It does not need any convert from mV to mA. Price is in USD. Any thoughts anyone? TIA!. • Only then can the tonal potential of the 300B be fully exploited. 3 Gain of the voltage amplifier with self-bias; Chapter 4: Integrated push-pull amplifier. By Tim F, 1 hour ago in 2 Channel. The 6L6GC tube is a 30W valve. It costs nothing to do so as a manufacturer, but we refuse to follow the pack. I had all Winged C 34's in the RM100 biased up each one between 30mV and 31mV. Output Transformer. 300B 2A3 101D EL34 KT88 6L6 6V6 Bias Current Plate Voltage Tester Vacuum Tube B3 3. Bias setting (in conjunction with rear panel control) Tube Tester (tests at actual voltage and. The g1 biasing for UL is the same as for triode connection, and a rough estimate of -Vdc g1 bias may be calculated :-. The cheap way to get more power from a tube amp is to raise the tube’s plate and screen voltage, and bias them harder. ; BiasPro VI-8C: Bias and plate voltage combo probe for common 8pin octal tubes. I can, and I do, when I use a bias measurement tool, raise the ma for the KT120's, not by much though. REFURBISHMENT and VERIFICATION of the HEATHKIT TT­1 TUBE TESTER Kent Nickerson Dedicated to the memory of Lloyd Generoux, who introduced me to the wonders of old technology. Pentode, made in Russia In 1959 Tung-Sol developed a premium, up-rated version of the 6BQ5/EL84 for use in industrial and military circuits. EL34 KT88 5881 6L6 KT66 6550 Vacuum Tube Tester Amplifier Bias Current AK985 T3 - $44. The Dialogue Premium's biasing system allows for the use of EL34s, KT88s, and even the trendy KT120s. grids of the KT150/KT120 output tubes through a pair of coupling capacitors that provide low frequency loop-gain stability. The 150V zener establishes the DC voltage window within which the NPN transistor works. Bias Calculator. Product DescriptionBrand : AK985Model : T3It's suitable for EL34 KT88 6L6 6CA7 6V6 5881 6550 KT66 KT100 KT120 3. Output Transformers: Interleaved windings, super wide-band, low leakage inductance, proprietary design. The self-bias voltage and the peak-to-peak voltage were influenced by both bias and source RF power in the high-density plasma. has recreated the Genalex Gold Lion KT88 with gold plated grid wire, carbonized screen grids, and a tri-alloy clad plate structure. The 5881 should break up earlier. This is a single power amplifier DIY (Do It Yourself) kit, designed by Mr. If you can't get the bias that high the final bias resistor should be swapped for a different value. After making the correction, I noticed that not only was the switch’s effect subtle, but that I actually enjoyed the sound of the KT120 tubes set for EL34 bias. It costs nothing to do so as a manufacturer, but we refuse to follow the pack. With its auto-bias design, the VT80SE can also be used with KT120 or KT150 output tubes and the circuit will adjust immediately when a new tube is installed. And when I saw the anode curves for the KT120 it was all horrible to look at. Because of our tradition of supplying the highest quality tubes, we are proud that our ouput is the very best in the world for upgrade and replacement. Before you buy them, check. Scroll down to see sets of 2 (pair), 4 (quad), and 6 (sextet). The German page for the design states to bias the tubes at 500MV. Specifically designed for audio amplification, the KT88 has similar ratings to the American 6550 which was designed for use as a servo. It requires about -65vdc, and that's at the full 60 watts dissipation per tube. This runs the tube at full rated plate voltage, and plots the curves at 10 different grid bias levels. As concrete example, in class A the KT88 tubes get a 450V power voltage, whereas in class AB they get 520V, which is the reason the max power is limited at 30W in class A, but it the same time the evidence it is a true. I see New Sensor is putting out Tungsol KT120 tubes whch bias like KT88 but have Pda = 60W. Single-Ended Class A (c) Nelson Pass, Pass Labs Pass Labs: Articles: Single-Ended Class A page 1. Bias value is adjustable by -VB1 and -VB2 , and you can check direclty the emission current with mA-meter (Milliammeter) , so you can use KT88, 6650, 6L6, EL34 tube with different bias value: HIFI EXQUIS use double packages to ship this amplifier. One 12AX7, two 12AT7’s, four KT120’s (optional: KT88 or 6550) Hum and Noise: Better than 100 dB below 75 Watts, A-weighted. Cathode bias KT88 KT120 KTxx Push-Pull Amp. The output tubes are arranged in push-pull parallel, four in all. It can be work with all kinds of multi meter (Digital meter or analog pointer meters) , at range of 100mA or above. This information is for reference only. This is a single power amplifier DIY (Do It Yourself) kit, designed by Mr. Lab12 Integre4 Audiophile Integrated Amplifier NEW Integre4 – The centre of your modern high end audio system. All this with no global negative feedback. 500v plate, 300v screen, -30. - Massive fully regulated high voltage supply - Matched quad output tubes - Heavy-duty gold plated RCA inputs - Heavy-duty gold plated binding posts - User selectable 4 and 8 ohm output taps - User selectable triode or ultralinear output - (4) KT120, (2) 12AU7, (2) 12AX7 tube complement - Built in bias meter - Integral tube cage. Tadaatsu Atarashi. 2 types of amplifier modes - Switch between Ultra Linear and Triode. Tube bias is controlled by two KT120 tubes, each driving a bank of eight tubes. 50 Ohm bias tees or bias Ts from Pasternack are available with two different bias connector designs including solder pin and SMA female. The meters offer a simple, unambiguous indication of each tube’s status compared to conventional LED bias monitors. warm-up/brown-out mute. Question - bias of KT120 valves Sign in to follow this. The main vantage here is the low cost and ofcourse a triode could be used instead the pentode in triode connection as show. It requires about -65vdc, and that's at the full 60 watts dissipation per tube. com where the poster has an Dynaco ST120 he experimented with bias settings from 0. The Eiclone is a standard fixed bias design, where the user must adjust the voltage (a not dangerous ~1 volt) on each output tube, while monitoring with an inexpensive multimeter. After extensive research and engineering, New Sensor Corp. By considering stress bias, stress time, and operation temperature, the bias stress effect on the threshold voltage has been modeled and calibrated with measured samples. Protective fuses are installed for each output tube and can be replaced if the need ever arises. The amp is a fixed bias job that runs a very high plate voltage - the transformer in my amp supplies 485 volts to the power tube plates. W: Screen Voltage (max) 600. From the first steps of our design, we focused on achieving a wide open sound which is usually unprecedented in an integrated amplifier. With its auto-bias design, the VT80SE can also be used with KT120 or KT150 output tubes and the circuit will adjust immediately when a new tube is installed. Voltage amplification tube : ECC81/12AT7 x 4 pcs. The cheap way to get more power from a tube amp is to raise the tube’s plate and screen voltage, and bias them harder. Due to the high voltage in the circuit, biasing an 845 / 805 or 211 amp improperly may expose you to lethal high voltage causing instant death. Tube Complement: One 12AX7, one 12AT7, one 6AL5, six KT120 Hum and Noise: Better than 120 dB, referred to 350 watts, A-weighted Bias: Rear panel potentiometer adjust, front panel meter. This means that with the flip of a switch you can choose for the optimum bias setting for EL34 type of tubes or KT88/KT120 type of tubes. What most companies call Auto Bias is actually "Cathode Bias"- A commonly used method that is cheap to make, and often found in guitar amps, but also $20,000 high end audio amps. compatible amplifier is difficult to use. I think with the KT88s in place the amp was becoming unstable at very low frequencies. I am thinking that a possibility are the bias resistors. ; BiasPro 9C: Bias probe in measuring cathode current on 9pin miniature tubes. Get an amp without tubes. The 5881 SHOULD be ok with the plate voltages found in most guitar amplifiers designed for the 6L6GC. Four-function mete r. You may have to register before you can post: click the register link above to proceed. 2Vdc, similar for all 4 new KT150 tubes. The heart of the Rogue Audio Stereo 100. Voltage: 115-120V or 230-240V, 50-60 Hz. KT120's can be used in place of KT88's in many amps, as long as the power supply, and bias system can accomodate them, the heater current with the KT120's is a little higher ie; around 150, to 200ma more than a regular KT88, However, the surge current is greater, especialy with the KT150's,[in excess of 3 amp initialy] But both the KT120's and KT150's settle down after a couple of seconds. I simply adjust the fixed bias to obtain 120ma or 100ma or 75ma with each respective power tube. I say not dangerous (electrically), but the circuit board is laid out with the bias adjustment almost between the two power tubes. KT120 Push-Pull Tube Amplifier Schematic (Oddwatt Audio OBHO) This KT120 tube amplifier is a follow on to the smaller Oddwatt power amplifier. CHAMP ELECTRONICS -" THE VINTAGE VALVE AMP HOSPITAL" NOTTINGHAM, ENGLAND. 75ma bias setting and that experiment was a disaster. Cathode bias amplifiers use a cathode resistor to generate a positive bias voltage on the cathode while the grid is grounded through a 'grid leak' resistor. Jim Clark Stereo has sold these amplifiers all over the world and the feed back has been terrific. • Heating and operating voltage are electronically controlled, sound instabilities due the fluctuating mains voltage is a thing of the past. If an op-amp is said to be biased to 2. With a single switch you can calibrate the amplifier for EL34 or KT88/KT120 valves, thereafter you can leave it alone. select the first character of the tube. Huge 400W toroidal transformer guarantees high margin of spare power supply for amplifier. actual power output is dependent upon both line voltage and “condition” i. View details & Buy. Lab12 Integre4 Audiophile Integrated Amplifier NEW Integre4 – The centre of your modern high end audio system. Audio Research has added a new flagship, tube-based mono-block amplifier to its Reference Series. If you are inclined, measure the voltage across the bias resistor when a new set of tubes has been installed - well. I recently purchased a Cayin A88T integrated amp and have read a number of different recommended bias settings for this amp. 6550 / kt88 / kt90 KT88's generate a lot power, handling significantly more plate voltage than other power tubes. A built in bias meter simplifies keeping biasing. Enter plate voltage: Select output tube: EL84: 6v6: 6L6: 7027: KT66/EL34: 6L6GC: kt77: KT88: 6550: KT120: This information is for reference only. This will kill (and it has) most other new KT88's I have tried (except the Gold Lion, Electro-Harmonix and the JJ). Then factor in your transformer’s regulation and the variation in your mains voltage. G1 Bias Negative voltage to achieve a 50 mA cathode current at a given screen voltage GM Transconductance at 50 mA cathode current in micromhos. 2 amps current draw on your heater supply. Question - bias of KT120 valves. (For instance, an EL34-family tube tends to sound more lush and the 6550/KT88/KT120/KT150 family more clean and analytical. If you can't get the bias that high the final bias resistor should be swapped for a different value. We have batteries used on PCBs that work for more than 10 years with minimal voltage loss. There is an individual bias pot for each output tube, as well as a signal balance pot for the phase splitters. the KT120 need at least 90ma plus bias to sound good LT 67: I'm unfamiliar with the sound signature of the KT-120 (7. Audio Research 610T (NEW KT120's) R 600,000. The maximum output power of the amplifier closes from 2 x 1W for KT88 through 2 x 1,2W for KT120 to 2 x 1,5W for KT150. By comparing figs. 8 kQ VI) = -3 V 1 IOMQ IOMQ = 6 mA DSS 750 Q 6. I do know fixed conditions I'm aiming for, like expected power output (50w each tube), B+ ( probably 520VDC since that's what I have on hand), and cathode current which is what I've calculated to be 94mA per tube. Last Update: Description. Conrad Johnson mono-blocks LP125M SE, this is the special edition using KT120 tubes. Home Amplifier Tube Amplifier KT88 KT120 KTxx Tube Amp KT88 KT120 KTxx Push-Pull Amp YaQin MC-100B KT88 Push-Pull Tube Amplifier HIFI EXQUIS 6SN7 12ax7 Lamp AMP MS100B. 3 Design Maximum Values Class A - Class A Amplifier, Pentode Connection Amplifier, 800 600 600 -200 230 250 Grid #1 Voltage (negative bias value) Cathode Current Plate Dissipation Grid #2 Dissipation Cathode to Filament Voltage Typical Operation and Characteristics - Plate Voltage. Tube Dissipation Using Cathode Resistor Voltage Drop Please enter Tube Type and Plate-to-Cathode Voltage above before calculating Tube Dissipation. In this article, the 6550 is used in a clean, sweet-sounding, single-ended design. KT120's can be used in place of KT88's in many amps, as long as the power supply, and bias system can accomodate them, the heater current with the KT120's is a little higher ie; around 150, to 200ma more than a regular KT88, However, the surge current is greater, especialy with the KT150's,[in excess of 3 amp initialy] But both the KT120's and KT150's settle down after a couple of seconds. "Self-bias" (automatic) and "Fixed bias". Simply take the plate voltage and multiply it by the current measured in mA. G1 Bias Negative voltage to achieve a 50 mA cathode current at a given screen voltage GM Transconductance at 50 mA cathode current in micromhos. What most companies call Auto Bias is actually "Cathode Bias"- A commonly used method that is cheap to make, and often found in guitar amps, but also $20,000 high end audio amps. Plate Voltage, triode (Ua): ≤ 650 V, 400 V typical Plate Voltage, tetrode (Ua): 850 V Grid 2 Voltage: ≤ 600 V, 225 V typical Grid 1 Voltage: ≤ -200 V, -14 V typical Plate Dissipation (Wa): 60 W Grid 2 Dissipation: 8 W Cathode Current (Ik): 230 mA Grid Circuit Resistance (Rg), Fixed Bias: 51 kΩ Grid Circuit Resistance (Rg), Self Bias: 2. 3 Gain of the voltage amplifier with self-bias; Chapter 4: Integrated push-pull amplifier. the amp is musical paradise MP-501, single ended parallel mode using KT-120, whatever that means. What Exactly Is Bias? Before we talk about different types of biasing found in tube amps, it is probably a good idea to explain what exactly the bias is. For individual sound adjustment, the negative feedback can be adjusted in three steps, each for 4 and 8 ohms. Calculate approximate Eg1 bias. They are select by "Filament volt" / "Bias volt" selector. The product measures the cathode current of the power tube for bias reading (at low voltage side of the tubes ). The VT80 will also work with different types of output tubes, including. The cheap way to get more power from a tube amp is to raise the tube's plate and screen voltage, and bias them harder. Even if you are unable to bias the tube all the way down to the recommended current draw you can probably still use KT120 tubes. 0C3A / 0C3W Gas discharge tube / 105 volt regulator, octal base, aka VR-105, WY-3P A Gas discharge tube / voltage regulator is used as a shunt regulator to hold a voltage constant at a pre-determined level. Hybrid Tube/solid state rectifier system provides the stability of diodes with the smoothness of a tube rectifier. - RCA terminals are specially designed by Line Magnetic for the amplifier. EL34 KT88 6L6 6CA7 6V6 5881 6550 KT66 KT100 KT120 Vacuum Tube Tester Amplifier Bias Current Tool Radio Preamp mA Version V8 12-Plug Pro Audio Cable Tester - 12-in-1 Line Finder, Continuity Checker, Wire Tracker w/ Internal Battery, LED Light Indicator - Supports 12 Types of Cables, USB, RJ45, XLR, and More - Pyle PCT40 Apr 18, 2018 · These. To be able to supply this high current to the tubes, the PAB microprocessor changes the bias setting and main power voltage. When you changed the blew tubes, there must be some resistors out of their value. KT120 Push Pull Amplfier. For the M125 with KT88 power tubes, we recommend a bias level of 0. rockstah wrote:bias range is calculated by the b+ of the given amp. GOLD LION KT88 Made in England Draft of new spec sheet 4/30/2002 BEAM TETRODE 6-3V INDIRECTLY HEATED The KT88 has an absolute maximum anode dissipation rating of 42W and is designed for use in the output stage of an a. The A50i relies on two Tungsram ECC83 tubes for the input stage, with four E88CC tubes driving voltage and four KT120 pentodes for power output amplification. At a typical transconductance for 7000 umhos (7 mA/volt) the 10 volt difference will cause a 70 mA bias difference. the KT120 need at least 90ma plus bias to sound good LT 67: I'm unfamiliar with the sound signature of the KT-120 (7. The output tubes are arranged in push pull parallel, three up, three down for a total of six in all. I am surprised VTL hasn't jumped on the KT120 bandwagon and designed an amp around that tube if it's as great as those said it is. Three potted transformers reduce transfer noise, and the presence of the KT120--with 50% more power than the KT88--immediately yields improvements in sonics, power, and balances. BiasPro 8C: Bias probe in measuring cathode current on common 8pin octal tubes. 3 Design Maximum Values Class A - Class A Amplifier, Pentode Connection Amplifier, 800 600 600 -200 230 250 Grid #1 Voltage (negative bias value) Cathode Current Plate Dissipation Grid #2 Dissipation Cathode to Filament Voltage Typical Operation and Characteristics - Plate Voltage. EL34 KT88 6L6 6CA7 6V6 5881 6550 KT66 KT100 KT120 Vacuum Tube Tester Amplifier Bias Current Tool Radio Preamp mA Version V8 12-Plug Pro Audio Cable Tester - 12-in-1 Line Finder, Continuity Checker, Wire Tracker w/ Internal Battery, LED Light Indicator - Supports 12 Types of Cables, USB, RJ45, XLR, and More - Pyle PCT40 Apr 18, 2018 · These. Meixing MINGDA MC368-B KT88 Push-Pull tube amplifier HIFI EXQUIS 50wx2 integrated lamp 6n8p (6SN7) AMP with remote KT88 push pull integrated audio tube amplifier. One 12AX7, two 12AT7’s, four KT120’s (optional: KT88 or 6550) Hum and Noise: Better than 100 dB below 75 Watts, A-weighted. Biasing using their guidelines should be just fine (assuming you don't have abnormally high or low line voltage at your house). Tube CAD, Se Amp CAD, Audio Gadgets For those of you who still have old computers running Windows XP (32-bit) or any other Windows 32-bit OS, I have setup the download availability of my old old standards: Tube CAD, SE Amp CAD, and Audio Gadgets. (Note: 5U4G is 10% more current than silicon diode) and 5AR4 is higher voltage to get than direct heating valuve like a 5U4G. After making the correction, I noticed that not only was the switch’s effect subtle, but that I actually enjoyed the sound of the KT120 tubes set for EL34 bias. but KT88 are around 3. Followers 2. the voltage across the bias resistor. About twice the price of a 6550. Simple but highly effective discrete voltage regulators supply rock-solid stable DC voltage to the critical voltage gain and inverter stages. We were hoping the two would have a booth at CEDIA but they are walking around instead this year checking out the competition and serving as audiophile "booth. The most accurate method to test tubes, the curve plots can actually be compared to the printed examples for each tube type that appear in the manufacturer technical data sheets and books. KT88 upgrade Thought I was getting the KT120 when I did the upgrade. The probe is a 10X probe, meaning that the voltage is actually 10X larger than shown on screen. KT88 tubes draw ~1. 65 with no problems. It can be work with all kinds of multi meter (Digital meter or analog pointer meters) , at range of 100mA or above. QUAD TUBE AMP Bias Meter 6L6 El34 KT88 Probe with PLATE VOLTAGE MEASUREMENT - $69. Since its production ceased in the early 1980s, the Genalex Gold Lion KT88 has become expensive and hard to find. Inside Jadis Orchestra Reference chassis photo, you will find the bias of each tube can be easily adjust, I set the voltage across the Plate resistor is 0. Bias is the negative voltage we put on the control grid of a tube to make the tube conduct the current we desire. Plate Voltage Grid #2 Voltage Plate to Grid #2 Voltage 16. The small hole beside each KT120 tube is for bias adjustment - you will see a small screw in each hole. EL34 KT88 6L6 6CA7 6V6 5881 6550 KT66 KT100 KT120 Vacuum Tube Tester Amplifier Bias Current Tool Radio Preamp mA Version V8 12-Plug Pro Audio Cable Tester - 12-in-1 Line Finder, Continuity Checker, Wire Tracker w/ Internal Battery, LED Light Indicator - Supports 12 Types of Cables, USB, RJ45, XLR, and More - Pyle PCT40 Apr 18, 2018 · These. ” 'Nuff said, if you're a fan of Bob Carver and have the money. The KT120 is an impressive power valve with a long plate structure and huge grid cooling. Crossover Roll-Off. Allows measuring both the bias current and the plate voltage with a flip of the switch. For high frequencies (above 15 KHz), the treble boost will be typically of 10 dB with a cut at 11 dB. 61) It sounds very good to me. I do know fixed conditions I'm aiming for, like expected power output (50w each tube), B+ ( probably 520VDC since that's what I have on hand), and cathode current which is what I've calculated to be 94mA per tube. While similar in form to the ’60, the chassis has been reworked and refined to reflect the industrial design for which Audio Research is known: the front panel reflects those on full-size components, the perforated cover hearkens back to earlier Audio Research products, and the. We were hoping the two would have a booth at CEDIA but they are walking around instead this year checking out the competition and serving as audiophile "booth. I recently purchased a Cayin A88T integrated amp and have read a number of different recommended bias settings for this amp. There must be a reason why those tubes blew up. As the negative voltage supplied to the grid is a “fixed voltage” the amp is called a fixed bias circuit. The Bob Carver Crimson 275 has been making customers happy since its release late last year. A built in bias meter simplifies keeping biasing. Question - bias of KT120 valves. 845's are bright. How to use KT88 and KT120 tubes in the ProLogue One, Four, Six & DiaLogue One, Four, Six Adjusting the Adaptive AutoBias™ Board. And there came a day when I discovered that I’d spent a few hours listening with KT120 power pentodes, but with the tube-selector switch—which controls bias voltage—set for EL34. Re: KT120 bias voltage by Peter W. Dynaco™ replacement parts & vacuum tube audio amplifier kits. This perception of depth is influenced by the raw quantity of bias current. Biasing using their guidelines should be just fine (assuming you don't have abnormally high or low line voltage at your house). EL34 Push-pull Tube Amp Kit TU-8340 adopted "Semi-automatic bias adjustment system" - which allows users to adjust the bias simply by pressing buttons even if the model takes on the fixed bias method - no need of manual adjustment every time of tube rolling. The VT80SE tubed power amplifier is built to last a lifetime, and its quality is evident both on the inside and the outside. The product measures the cathode current of the power tube for bias reading (at low voltage side of the tubes ). I think with the KT88s in place the amp was becoming unstable at very low frequencies. Some amplifiers provide a bias voltage to the grids of the power tubes, but do not have a way to adjust the voltage. Tung-Sol KT120 x 4. Question - bias of KT120 valves. The KT77 avoids this. Voltage: 115-120V or 230-240V, 50-60 Hz. 4 ±100 pA At TA = –40°C to +85°C See. While similar in form to the ’60, the chassis has been reworked and refined to reflect the industrial design for which Audio Research is known: the front panel reflects those on full-size components, the perforated cover hearkens back to earlier Audio Research products, and the. Silverface Fender®s from the Fender® CBS era offer a bias balance control, which balances the bias between the output tubes, but doesn't really offer full bias adjustment. Hi-Fi Tube Amplifier 110V input Voltage Tubes: EL34*2 6N8P*2 5Z3P*1 Hi-end Tube Well balanced tone EL34 gives you outstanding highs mids when 6N8P brings deep lows Class A Single Ended Amplifier to reduce distortion Self-Biasing Design Analog Inputs Output tags for speaker impedance both 4ohm 8ohm Particularly Ideal for Vocals Strings Pipes and. Protective fuses are installed for each output tube and can be replaced if the need ever arises. The German page for the design states to bias the tubes at 500MV. As the guitar signal causes the current flow through the cathode resistor to fluctuate so does the voltage drop across the cathode resistor (the bias voltage). Question - bias of KT120 valves Sign in to follow this. Bob Carver describes the amplifiers as "stand[ing] with a small handful of the world's great vacuum tube amplifiers. KT88 Author: M-O Valve Subject: JA-FP-2000-10-01 Created Date: 10/1/2000 7:35:29 PM. The cheap way to get more power from a tube amp is to raise the tube's plate and screen voltage, and bias them harder. The VSi75’s wide bandwidth output transformers are the same as those in the remarkable Reference 75, and we also incorporate some key REF75 parts including proprietary coupling. biasing your amp ever again, and the need for matched tubes is eliminated. Calculate Plate Dissipation Based On Plate Voltage And Cathode Current Readings. Volt Ampere Meter measures voltage of 0-70V or 0-500V with 100mV resolution and current consumption 0-10A or more with 10mA resolution. About twice the price of a 6550. KT120 could have idle Pda = 36W with Ia 59mAdc, Ig2 6mAdc. Output Transformer. Simply take the plate voltage and multiply it by the current measured in mA. You will see claims of as high as 100 watts from a pair of KT120’s. The deceptively simple circuit uses a single NOS (new old stock) 12SL7GT driver tube and a pair of Tung Sol KT120 output tubes in a configuration the company calls unique and that skeptics said "couldn't work" but clearly does. Youll just have to do a little math to be sure the tubes are running safely. The purpose of this KT88 / KT66 /6550 / KT90 / KT120 page is to give an overview about what KT66, KT88. New Sensor, 55-01 2nd Street, Long Island City, NY 11101 Tel:718-937-8300 Fax: 718-937-9111 www. Operating Mains Voltage changeable with power transformer re-wiring and fuse value change. 2 –Un autre ultérieur avantage est, que la connexion est contrebalancé immédiatement du Input-terminal au Output-terminal. electron Tube Data sheets - Type index. FREQUENCY RESPONSE: (-3dB points at 1 watt) 0. Dynaco™ replacement parts & vacuum tube audio amplifier kits. KT120's can be used in place of KT88's in many amps, as long as the power supply, and bias system can accomodate them, the heater current with the KT120's is a little higher ie; around 150, to 200ma more than a regular KT88, However, the surge current is greater, especialy with the KT150's,[in excess of 3 amp initialy] But both the KT120's and KT150's settle down after a couple of seconds. KT120 or KT150 are used as power amplifiers tubes. The Challenger 250 is a single-track amplifier with quite a moderate size, although the output per track is up to 350W. Reply to this topic; Start new topic; Prev; 1; 2; Next; Page 2 of 2. Plate Voltage, triode (Ua): ≤ 650 V, 400 V typical Plate Voltage, tetrode (Ua): 850 V Grid 2 Voltage: ≤ 600 V, 225 V typical Grid 1 Voltage: ≤ -200 V, -14 V typical Plate Dissipation (Wa): 60 W Grid 2 Dissipation: 8 W Cathode Current (Ik): 230 mA Grid Circuit Resistance (Rg), Fixed Bias: 51 kΩ Grid Circuit Resistance (Rg), Self Bias: 2. For the M125 which KT120 power tubes, we recommend a bias level of 0. Question - bias of KT120 valves Sign in to follow this. Young Ahn 1,297 views. This added stage of filtration was originally designed into the SE input board to complement the Lower Voltage Amplifier Power Supply Kit for use in a SE 6C33C amplifier,. I prefer to use the fixed-bias circuit because the sound is very stable. A good few months ago back in 2010 I received an 'out-of-the-blue' phone call (which is quite often the case regarding enquiries like this) from a really nice gentleman named Andrew. Once the tubes are installed and the unit is poweredup, the VT80 will automatically adjust bias for each output tube. This means that with the flip of a switch you can choose for the optimum bias setting for EL34 type tubes or KT88 type tubes. One thing you read about from end users is the claim that Rogue's gear. TUBE CATHODE BIAS Current Probe Tester 8-Pin Socket for 6L6 6V6 EL34 KT88 6550 - $21. The correct BIAS is vital for the constant sound quality of the V 110 SE. Tung-Sol KT120 Super cool KT88 variant made by New Sensor in Russia. W (*) These specifications are provided 'as-is', with no. The recommended tube complement is 4 X KT88, 6550, KT90, KT100 or KT120 output tubes, 2 X 12AU7 or 12BH7 driver tubes, and a 5AR4/GZ34 tube rectifier or a Weber WZ68 Copper cap solid state rectifier. Re: Traynor YBA-1A KT-120 mod Help me please? by projectMalamute on Thu Dec 02, 2010 7:46 pm Some cursory poking around the net gives me these figures for current to the heaters: 1. The KT120 has far greater dynamics, is a more powerful power beam tetrode, has solid impact in the bass, holds the soundstage together extremely well, even on loud passages, and delivers a sort of "fuller sound". The switch between the two KT120 tubes is for checking bias. By allowing you to manually bias the quartet of main valves, you don't need to go for matched pairs or quartets because you can set each to output the same as the rest. The 50C has the highest plate voltage - higher than spec, about 410 between pins 3-8 (435 to ground - dropping 25 across bias resistor) and has the strongest 5u4GB tubes. com where the poster has an Dynaco ST120 he experimented with bias settings from 0. Dynaco™ replacement parts & vacuum tube audio amplifier kits. Huge 400W toroidal transformer guarantees high margin of spare power supply for amplifier. Young Ahn 1,297 views. There is no solid-state glare. So the 6L6GC will give you more power and more clean headroom. The heart of the Rogue Audio Stereo 100 consists of four matched KT120 output tubes operating in push-pull configuration. Power transformer is MX208 old Tango. Mechanical Data:. A set of green LED's, one for each KT120, are on the top plate to indicate the bias condition. V: Filament Current: 1. Voltage amplification stage: 2 stages, Phase inversion - differential amplifier (first stages) B -Power: MOSFET, ripple filter (for L and R separately) Tube options: Output tube : EL34/6CA7 (standard) x 4 pcs. You will see claims of as high as 100 watts from a pair of KT120's. Before insert KT88 check the bias voltage on grid setting the trimmer for the max negative voltage. I suggest if you have adjustable bias to measure the actual current to keep from smoking something. What most companies call Auto Bias is actually "Cathode Bias"- A commonly used method that is cheap to make, and often found in guitar amps, but also $20,000 high end audio amps. Before insert KT88 check the bias voltage on grid setting the trimmer for the max negative voltage. warm-up/brown-out mute. It has a new power transformer that was designed around the KT120 output tube. Own transformers. The recommended tube complement is 4 X KT88, 6550, KT90, KT100 or KT120 output tubes, 2 X 12AU7 or 12BH7 driver tubes, and a 5AR4/GZ34 tube rectifier or a Weber WZ68 Copper cap solid state rectifier. This tube is a drop-in replacement for KT88s no special re-wiring required! The KT120 is rated to have a plate dissipation of 60W compared with the 35W of the 6550, the 42W of the KT88, that's a lot of juice! The KT120 also draws more filament current from your amp's output transformer(s). 108: I use kt120 in SEP mode w/fixed bias (4. 4 ±100 pA At TA = –40°C to +85°C See. Bias is an alternating current of high frequency which is applied to the tape recorder to reduce distortion. As concrete example, in class A the KT88 tubes get a 450V power voltage, whereas in class AB they get 520V, which is the reason the max power is limited at 30W in class A, but it the same time the evidence it is a true. I am surprised VTL hasn't jumped on the KT120 bandwagon and designed an amp around that tube if it's as great as those said it is. Tung-Sol KT120 x 6. is the power rating of the power tube, is the bias current, and. Most Marshall® amps with 8-pin output tubes offered adjustable bias up through the 1990's. for an amp with a B+ of 480dcv, 70%MPD would be 36mA 2. - Massive fully regulated high voltage supply - Matched quad output tubes - Heavy-duty gold plated RCA inputs - Heavy-duty gold plated binding posts - User selectable 4 and 8 ohm output taps - User selectable triode or ultralinear output - (4) KT120, (2) 12AU7, (2) 12AX7 tube complement - Built in bias meter - Integral tube cage. 7dBW) at 1% THD—the Titan Atlas Magnum is more linear below clipping with KT120s than with KT90s. Note that the Premium Series, like all PrimaLuna designs, is compatible with the KT120, which should be used in the KT88 bias setting. TUBES To create a push pull amplifier is possible to use triode and pentode but obviously to test many configurations like the ultra linear we need a pentode. What most companies call Auto Bias is actually "Cathode Bias"- A commonly used method that is cheap to make, and often found in guitar amps, but also $20,000 high end audio amps. I'm probably not going to switch over to them just for the fact I've read if the amp wasn't designed around them I shouldn't see any bump up in power only a subjective improvement in tone -if at that. CR type equalizer from negative effects was to develop a separate power supply unit. For example, if the gate requires positive voltage to conduct, forward biasing adds positive voltage. Probably, the KT120 will last longer in an amp which has just the one shared grid bias voltage supply, or two, to the 1, 2, or 3 tubes each side of the PP circuit, and this is because one would use the same bias current in KT120 as in 6550, in a bass amp. If an op-amp is said to be biased to 2. I now have all of them at just over 31mV. fixed bias self bias bulb temperature 850 650 650 600-200 60 8. Cheap valve tube amplifier, Buy Directly from China Suppliers:Douk Audio HiFi Dual Bias Current Probes Tester Meter for EL34 KT88 6L6 6V6 6550 Vacuum Valve Tube Amplifier Enjoy Free Shipping Worldwide! Limited Time Sale Easy Return. 8 kQ VI) = -3 V 1 IOMQ IOMQ = 6 mA DSS 750 Q 6. BiasPro VI-9C: Bias and plate voltage combo probe for common 9pin. The Chinese site for this amp states 400MV. 1pcs T4 Tester. • TACs marked L are to be used in amplifiers with a plate voltage between 250 and 350 volts DC. View details & Buy. The driving voltage as well as. 5mm Male Plug and Banana Plug Copper used for excellent conductivity. power amp-tubes (EL34, KT88, KT120 and KT150). All this with no global negative feedback. Audio Research 610T (NEW KT120's) R 600,000. A byproduct of the regulator is a slightly quieter output. What most companies call Auto Bias is actually "Cathode Bias"- A commonly used method that is cheap to make, and often found in guitar amps, but also $20,000 high end audio amps. ð•"On-the-Fly" Triode/Pentode Switching. The purpose of this KT88 / KT66 /6550 / KT90 / KT120 page is to give an overview about what KT66, KT88. Then factor in your transformer’s regulation and the variation in your mains voltage. The VT80SE tubed power amplifier is built to last a lifetime, and its quality is evident both on the inside and the outside. 6 amp volts volts volts grid 1 to plate input output. ) Grid #1 Driving Voltage (when P = 50 mW) Grid #1 Driving Voltage (when P = 6 W) Output Power (at 10% THC) with fixed grid bias) Output Power (when I 0. Support 4Ω-8Ω loudspeakers, KT120 / KT150 power tube (55W per channel). New (2) 7247 and (4) EL84 NOS Tubes. Only a few of the most popular tubes are shown. EL34 Triode Connection Non-NFB Push-Pull with Hashimoto Transformers - Project #1. select the first character of the tube. A massive fully regulated power supply ensures that low frequency information will not go unheard, and that the power and attack of transient musical passages will be recreated in full. In contrast, reverse bias holds the device in a non-conductive state until the sum of the control voltage and bias is sufficient to bring it to the. Young Ahn 1,297 views. The Heathkit TT­1 Assembly and Operating manuals are arranged logically enough. It costs nothing to do so as a manufacturer, but we refuse to follow the pack. Huge 400W toroidal transformer guarantees high margin of spare power supply for amplifier. If you want Audio Research sound without the price of their Reference series, this amplifier delivers!. Some amplifiers provide a bias voltage to the grids of the power tubes, but do not have a way to adjust the voltage. Direct Price: $3,875 with KT88/KT120 or $4,200 with KT150. T-2000 KT120 STEREO INTEGRATED AMPLIFIER voltage gain, instead of three or four stages as one finds in many conventional integrated amplifiers. ), directly heated triodes cannot operate directly in parallel because of the complex demands on the heating system needed increase output power. As the bias is reduced the perception of stage depth and ambiance will generally decrease. Money Back Guarantee Refund in. TUBE CATHODE BIAS Current Probe Tester 8-Pin Socket for 6L6 6V6 EL34 KT88 6550 - $21. Output Tube Biasing, An Introduction - Part 2. At the same time, however, the unregulated bias voltage becomes more negative, biasing the power tubes colder, thus offsetting this effect somewhat. About twice the price of a 6550. The 845SE glows in the dark. I keep running into tubes that don't list this so I need to be able to determine it. Followers 2. Bias with these tubes is actually something to be concerned about. Describe your experience with the Knight T-150 and tell us why you give it the rating you did (required). The cheap way to get more power from a tube amp is to raise the tube's plate and screen voltage, and bias them harder. Buy your own. The 845 SE is the evolution of the O2. TUBES REQUIRED 2 - Matched pair KT120. KT90 and types and brands exist, and what you can do with the this tube. Huge 400W toroidal transformer guarantees high margin of spare power supply for amplifier. After you’ve completed the bias adjustment changes, it is a good idea to go back and check the bias measurements for all the other tubes since changes made to one tube could possibly affect the setting of all the others. EL34 KT88 5881 6L6 KT66 6550 Vacuum Tube Tester Amplifier Bias Current AK985 T3 - $44. Plate and screen voltage. You will see claims of as high as 100 watts from a pair of KT120's. The Audio Research VT80SE Special Edition Tube Power Amplifier provides a spectacular soundstage and a natural sounding presentation. Uses the new Tungsol Kt120 Cryoed Tubes or the JJ KT88 Cryoed Tube; Output Power 100 Watts RMS with the KT120 tubes and 75 Watts with the KT88 tubes. I keep running into tubes that don't list this so I need to be able to determine it. Price is in USD. It uses a 6922 for input, ECC99 for splitter. To avoid serious and permanent tube damage when constructing an amplifier, always ensure the grid bias voltage is present at grids 1, 2 and 3 before applying B+ high voltages to the circuit. Nobsound Vacuum Tube Amp Amplifier Plate Bias Current Probe Tester 8 Pin Socket for EL34, KT88, 6L6, 6V6, 5881, 6550, KT66, KT100, KT120, 7027 (CT1-P, Plate Current. 6SN7 or 6SL7 driver stage in SRPP mode. Based on his earlier constructions warmly adopted by HiFi enthusiasts all over the world, TU-8200R is the fantastic amp which can give you a lot of great fun while building it and fantastic musical experience later on. 1 Output stage, or power stage. where V is bias voltage, J is the voltage-dependent forward current density, T is temperature, and [gamma] is the first integer higher than the n value. The KT88 / KT66 /6550 Directory. In all normal circuits higher bias voltage (that's a higher negative voltage) means lower idle current and vice versa (the bias voltage acts to "squeeze off the current"). ) The components I have are sort of on the cusp of when this particular company moved from an older design that was a bit warmer and less analytical to the opposite, so it is like having the best of both worlds. The Maggie is very forgiving re: biasing because of the cathode bias on the power tube. Ceramic socket and gold pins for long life,Tough gold pins with a thick gold. Before insert KT88 check the bias voltage on grid setting the trimmer for the max negative voltage. A set of green LED's, one for each KT120, are on the top plate to indicate the bias condition. Add to Favorites Seller Join newsletter Payment Shipping Return Policy About Us Contact Us View All Categories Nobsound®——Douk Audio Germany Warehouse USA Warehouse UK Warehouse HiFi Art-Elfidelity Hi-Fi Tube Amplifier Famous Brand Amplifier Integrated Amplifier Digital Amplifier Phono Pre-Amplifier. For example, in the HK-10 the bias voltage is applied to the KT-88's grid via a 100K resistor from the "fixed bias adjustment" Yellow_Light_Colorz_PDT_17 resistor network. Posted on 2017/11/15 by Steve Graham in Amplification, it might be possible to swap out resistors to increase the current draw to work more optimally with a 6550 or KT120. 1 Fixed bias for vacuum tubes; 3. Tube bias is controlled by two KT120 tubes, each driving a bank of eight tubes. V: Filament Current: 1. The typical 50 Hz AC heater voltage would cause unacceptably high hum and power disturbances in the speaker. This will kill (and it has) most other new KT88's I have tried (except the Gold Lion, Electro-Harmonix and the JJ). The maximum output power of the amplifier closes from 2 x 1W for KT88 through 2 x 1,2W for KT120 to 2 x 1,5W for KT150. The meter uses PIC16F876A microcontroller with 16x2 backlighted LCD. line voltage. fixed bias self bias bulb temperature 850 650 650 600-200 60 8. 0C3A / 0C3W Gas discharge tube / 105 volt regulator, octal base, aka VR-105, WY-3P A Gas discharge tube / voltage regulator is used as a shunt regulator to hold a voltage constant at a pre-determined level. After you've completed the bias adjustment changes, it is a good idea to go back and check the bias measurements for all the other tubes since changes made to one tube could possibly affect the setting of all the others. KT120s bias at a different point. Tube compliment: four- KT120, two- ECC99, two- 12AU7. KT120s bias at a different point. Hybrid Tube/solid state rectifier system provides the stability of diodes with the smoothness of a tube rectifier. Forward bias voltage brings the transistor or tube into or closer to its conductive state. : if power line has high distortion, maximum power will be affected adversely, although from a listening standpoint this is not very critical. 5" x 11" printing. The new KT120 has 50% more power than the KT88 tube. Here at Dynakit™ you will find the right parts to restore, repair or upgrade your original Dynaco™ vacuum tube amplifier. User bias control has been used for bias adjustment. Due to the high voltage in the circuit, biasing an 845 / 805 or 211 amp improperly may expose you to lethal high voltage causing instant death. Factory set for 100V, 120V or 220-240VAC operation for original destination country's mains voltage. If you want Audio Research sound without the price of their Reference series, this amplifier delivers!. 5mm Male Plug and Banana Plug Copper used for excellent conductivity. Allows measuring both the bias current and the plate voltage with a flip of the switch. New (2) 7247 and (4) EL84 NOS Tubes. Specification and max ratings(*) Filament Voltage: 6. Specifications and Features. I say not dangerous (electrically), but the circuit board is laid out with the bias adjustment almost between the two power tubes. After you’ve completed the bias adjustment changes, it is a good idea to go back and check the bias measurements for all the other tubes since changes made to one tube could possibly affect the setting of all the others. No hassle with screwdrivers, no messing around with meters etc. All models are available in three distinct high voltage ranges. For individual sound adjustment, the negative feedback can be adjusted in three steps, each for 4 and 8 ohms. Under the exact same operating conditions (e. HT @ 435 volts but now with the -52 volts bias rail added gives us a total usable voltage of 487 volts), raising both the drive voltage and clipping points. It will be found that a quad of 6550, KT88, KT90, KT120 will do at least the same work as 6 x EL34, and the same PSU can be used but with one less differential amp for balanced bias. 1pcs T4 Tester. Presetting the AB-Q-M125 module bias level: Before the AB-Q-M125 module can be fully wired up, you need to preset the bias voltage on the AB-Q-M125 module. The VT80SE tubed power amplifier is built to last a lifetime, and its quality is evident both on the inside and the outside. The Challenger 250 is a single-track amplifier with quite a moderate size, although the output per track is up to 350W. how to measure bias B+ filament voltage without opening bottom cover, 300B KT120 EL34, multimeter - Duration: 4:28. It's suitable for EL34 KT88 6L6 6CA7 6V6 5881 6550 KT66 KT100 KT120. Posted on 2017/11/15 by Steve Graham in Amplification, it might be possible to swap out resistors to increase the current draw to work more optimally with a 6550 or KT120. as KT120 Single-Ended Amplifier sound from Raspberrypi 3 Runeaudio bias is high voltage, low current and impedance is high like from 5K to 3. Specifications and Features. It uses only two stages of driving circuit to achieve +35dB of voltage gain, instead of three or four stages as one finds in many conventional integrated amplifiers. for the poseidon board to drive KT120,KT100,KT90 tubes to full output or close to, would it be a matter of just having a bigger power transformer and adjusting the bias to suit the larger plate dissapation of these tubes or would resistor values etc have to be changed or is it possible at all. One hundred watts per channel, Class AB Integrated Stereo Amplifier with KT120 output power tubes, 12AX7, 12AU7 and 6SN7 input tubes. it voltage operation maximum heater-cathode voltage heater negative with respect to cathode fixed bias self bias bulb temperature average characteristics class al audio amplifier - single tube. Anyone who listens to the M-100 never feels the need for more wattage, all they want to do is put on more music. KT88 Author: M-O Valve Subject: JA-FP-2000-10-01 Created Date: 10/1/2000 7:35:29 PM. The R5 100k (100,000 ohms) Plate Load resistor transforms the triode circuit from a current amplifier to a voltage amplifier. 65 amp per tubes, KT120 draw up to 1. The purpose of this KT88 / KT66 /6550 / KT90 / KT120 page is to give an overview about what KT66, KT88. Lab12 Integre4 Audiophile Integrated Amplifier NEW Integre4 – The centre of your modern high end audio system. threshold voltage shift, dVth, appears in IV characteristics of a-Si:H TFT as the integration of the flat band voltage shift Δvfb along the channel. Tube bias of an amp is used to find the optimum setting for the flow of current in the tube when the amp is idling. R1 and R2 need to be chosen to give a peak-voltage-output of ~1V. One thing you read about from end users is the claim that Rogue's gear. 1 Fixed bias for vacuum tubes; 3. The preamplifier and booster tubes use 6J8P (6SJ7) tubes dedicated for audio amplification. there have been a significant number of problems with current production KT120 and KT150 Tungsol tubes in power. (3) and (4), the threshold voltage dependence on the drain-bias is obtained with η η η − − + = ⋅ 2 2 2 3 2 2 th0 th dV dV (8) where dVtho is the threshold voltage shift when. KT88 upgrade Thought I was getting the KT120 when I did the upgrade. The product measures the cathode current of the power tube for bias reading (at low voltage side of the tubes ). CR type equalizer from negative effects was to develop a separate power supply unit. So that’s quite a big difference. The peak value of the sinusoidal input voltage, Egm which gives the indicated power output, Pm and harmonic levels, F2m and F3m for each point in both the curves and the table, is numer- ically equal to the grid biasing voltage at that point. Calculate Plate Dissipation Based On Plate Voltage And Cathode Current Readings. Hard to find parts including Dynakit™ original drop-in replacement components typically ship within 24 hours of ordering. After you’ve completed the bias adjustment changes, it is a good idea to go back and check the bias measurements for all the other tubes since changes made to one tube could possibly affect the setting of all the others. They emailed back advising against using the 120s-no surprise there. PFM setup for 5420/5500/5600 AFM system. In the case of dual-gate OFETs, the same V GS was applied to bottom gate and to gate electrode. Due to the high voltage in the circuit, biasing an 845 / 805 or 211 amp improperly may expose you to lethal high voltage causing instant death. If you want Audio Research sound without the price of their Reference series, this amplifier delivers!. It reduces the available power of the amp and runs the tubes hard, meaning shorter tube life and failures via "shorts". CHAMP ELECTRONICS -" THE VINTAGE VALVE AMP HOSPITAL" NOTTINGHAM, ENGLAND. KT88, KT120- Le systeme brevété ABR adapte le courant de bias automatiquement. The configuration in section C shows a simple approach for PFM experiments with high voltage bias, using a commercially available stand-alone high voltage amplifier. 1 In traditional audio parlance, any architecture in which signal-grid bias is supplied by a dedicated supply of negative voltage is referred to as a fixed-bias circuit, even though that voltage can and must be changed from time to time. I am wondering what is the problem with using 220k since my current build uses a LARMAR Master which is just over 225k. A range of the more obscure amp building tools and items, from drill large holes for sockets to building turret boards for you custom amp build, we have everything you need. A set of green LED's, one for each KT120, are on the top plate to indicate the bias condition. EL34 with B+ set to 500v: Plate=455v, G2=441v, Ia=68ma: 12w RMS clean, 16w total. It is no problem to use KT120 for CS-600 due to self-biasing system, however, some people who tried KT120 for CS-600 said the sound of KT120. I love the sound my Yaqin MC100B, I removed all china made tubes and put in 4 Tung-Sol Kt120 (set bias with 4 cheap multimeters to 0. The Eiclone is a standard fixed bias design, where the user must adjust the voltage (a not dangerous ~1 volt) on each output tube, while monitoring with an inexpensive multimeter. This product is suitable for EL34,KT88,6L6,6V6,5881,6550,KT66,KT100,KT120,7027 The product measures the cathode current of the power tube for bias reading (at low voltage side of the tubes ). You will see claims of as high as 100 watts from a pair of KT120's. It does not need any convert from mV to mA. Bias value is adjustable by -VB1 and -VB2 , and you can check direclty the emission current with mA-meter (Milliammeter) , so you can use KT88, 6650, 6L6, EL34 tube with different bias value: HIFI EXQUIS use double packages to ship this amplifier. KT90 and types and brands exist, and what you can do with the this tube. This results in the grids being negative with respect to the cathode. 2 Cathode bias or self-bias for vacuum tubes; 3. on Wed Mar 15, 2017 3:26 pm Generally, unless Zero, and generally, as long as all (tubes) are biased the same, improper bias will be inaudible at normal volumes. Weight: 26 lbs. From speakers to batteries to transformers and many other components. The 150V zener establishes the DC voltage window within which the NPN transistor works. GOLD LION KT88 Made in England Draft of new spec sheet 4/30/2002 BEAM TETRODE 6-3V INDIRECTLY HEATED The KT88 has an absolute maximum anode dissipation rating of 42W and is designed for use in the output stage of an a. You can substitute EL34’s for the KT88’s, and switch the toggle on the side to give the proper bias voltage for the EL34’s vs. Classic 60's Dynaco ST35 Tube Amplifier. Outstanding soldering taken in every adapter. • TACs marked L are to be used in amplifiers with a plate voltage between 250 and 350 volts DC. I see New Sensor is putting out Tungsol KT120 tubes whch bias like KT88 but have Pda = 60W. Page 1 350 Watt Vacuum Tube Amplifier Owner's Manual; Page 2 CIRCUIT DESCRIPTION The input stage consists of a 12AX7 current sourced long-tailed balanced pair, which is direct coupled to a second long-tailed balanced pair comprised of a 12AT7. Tadaatsu Atarashi. (We always need the drive to be clean, unclipped before the output stage clips!). In considering the fact that output voltage of a standard preamplifier is more or less 40V,. 2dB) -55kHz - 3dB. Pentode, made in Russia In 1959 Tung-Sol developed a premium, up-rated version of the 6BQ5/EL84 for use in industrial and military circuits. It costs nothing to do so as a manufacturer, but we refuse to follow the pack. According to the manual, I am in range on the cooler side. Calculate Plate Dissipation Based On Plate Voltage And Cathode Current Readings. It includes three 10H Trafomatic smoothing inductors for the G2, driver stage and high-voltage power supplies. KT120 or KT150 are used as power amplifiers tubes. In the first step the microcontroller drops bias voltage to a very low level called the "safety zone" to reduce the output tube current. the KT88's. max AC voltage is 320V so will be get 370V DC if use silicon diode. Adaptive Autobias is a circuit that takes care of bias, it ensures that each valve gets an optimal voltage, there is even an indicator for every power valve that lets you know when it has reached the end of its lifespan. It costs nothing to do so as a manufacturer, but we refuse to follow the pack. The REF160M also features a proprietary auto-bias circuit that works with various tubes types, including 6550, KT88, and KT120, in addition to the supplied KT150 and works constantly to maintain precise bias of the output tubes, while also adjusting for tube wear. The Auto Bias module will compensate for aging tubes as well as the slight difference bewteen each KT120 power tube to keep the bias for each tube at the pre set optimum operating level for the best sound and longevity of each KT120 output tube. Selection of tsl100 boards, marshall caster and amp knobs. CHAMP ELECTRONICS -" THE VINTAGE VALVE AMP HOSPITAL" NOTTINGHAM, ENGLAND. Operating in class A up to 400 watts, the XA200. The output tubes are arranged in push pull parallel, three up, three down for a total of six in all. 4 and 8 ohm speakers output (24W/Channel KT120) (15W/Channel KT88 Stock Tube) 3. It's suitable for EL34 KT88 6L6 6CA7 6V6 5881 6550 KT66 KT100 KT120 3. Output Power 100 Watts RMS with the KT120 tubes and 75 Watts with the KT88 tubes; Primary Voltage is custom wound to suit customer. Voltage: 115-120V or 230-240V, 50-60 Hz. And speaking of simple, maintenance of the Classic amplifiers could hardly be easier: the owner need only make a simple bias adjustment using the built in bias indicators when installing fresh output tubes. You have to re-bias the amplifier when you change from 6550 to KT120. The screen voltage in both cases was 300V. 6V or 600mV. Reply to this topic;. the KT88’s. Even if you are unable to bias the tube all the way down to the recommended current draw you can probably still use KT120 tubes. Followers 2. After making the correction, I noticed that not only was the switch's effect subtle, but that I actually enjoyed the sound of the KT120 tubes set for EL34 bias. Electro-Harmonix owns 100% of the largest remaining vacuum factory in the world. With its auto-bias design, the VT80SE can also be used with KT120 or KT150 output tubes and the circuit will adjust immediately when a new tube is installed. This will kill (and it has) most other new KT88's I have tried (except the Gold Lion, Electro-Harmonix and the JJ). Single-ended triode voltage gain and inverter stages are coupled to an output stage comprised of a single pair of ultra-linear operated EL34 tubes for each channel. If you have an auto/self bias KT88 amp, the KT120 should be a direct replacement as long as the power transformer can handle the extra filament current and not getting too hot. It is about as large as that design can be pushed. 2 x 12SN7 – Auto-bias 4 x 6550 (supplied), KT88, KT90, KT100, KT120– Power tubes Auto-biased power tubes, interstage transformers IMPORTANT: USING YOUR VACUUM TUBE AMPLIFIER • Do not unplug an interconnect while the amplifier is on • Do not unplug a speaker cable while the amplifier is on. com KT-150 Tube. No hassle with screwdrivers, no messing around with meters etc. Tadaatsu Atarashi. Operating voltage is 230v, 50/60Hz. 1 there is the inut diagram In fig. Biasing using their guidelines should be just fine (assuming you don't have abnormally high or low line voltage at your house). and uses a modified VTA Mark III driver circuit. The 5881 valve is a 23W valve. The output power of single tube can reach 6. ; BiasPro VI-8C: Bias and plate voltage combo probe for common 8pin octal tubes. I am surprised VTL hasn't jumped on the KT120 bandwagon and designed an amp around that tube if it's as great as those said it is. Simply take the plate voltage and multiply it by the current measured in mA. The input stage is stocked per channel with a fine 6SL7 double triode. According to the manual, I am in range on the cooler side. It reduces the available power of the amp and runs the tubes hard, meaning shorter tube life and failures via "shorts". at plate voltage ,I have 405V same voltages when use KT88/6550. EL34 KT88 6L6 6CA7 6V6 5881 6550 KT66 KT100 KT120 Vacuum Tube Tester Amplifier Bias Current Tool Radio Preamp mA Version V8 12-Plug Pro Audio Cable Tester - 12-in-1 Line Finder, Continuity Checker, Wire Tracker w/ Internal Battery, LED Light Indicator - Supports 12 Types of Cables, USB, RJ45, XLR, and More - Pyle PCT40 Apr 18, 2018 · These. Most Marshall® amps with 8-pin output tubes offered adjustable bias up through the 1990's. Scroll down to see sets of 2 (pair), 4 (quad), and 6 (sextet). Able to utilize EL34, KT88, KT120 and KT150 tubes to produce anything from 20 watts of Triode-strapped sound to 80 watts of ultra-linear power- these mono blocks are robustly over-built and can handle virtually any speaker with ease! Features Compatible with EL34, KT88, KT120 and KT150 power tubes; Compatible with 6SN7 or 6SL7 input tubes. What most companies call Auto Bias is actually "Cathode Bias"- A commonly used method that is cheap to make, and often found in guitar amps, but also $20,000 high end audio amps. 5 repeats the measurements with the amplifier fitted with KT120 output tubes, each biased to the same 35mA. Money Back Guarantee Refund in. The A50i relies on two Tungsram ECC83 tubes for the input stage, with four E88CC tubes driving voltage and four KT120 pentodes for power output amplification. Also the most common electrical circuits are given for KT88 and 6550. 95 amp per tube. With a flick of a switch, you can set your amplifier up to operate 6550, KT 88, KT 120, KT 150 or EL34 Vacuum Tubes. The frequency range of the RE 320 extends from an amazing 5 Hz to 85 kHz. According to the manual, I am in range on the cooler side. The author cames no responsibility for any information provided. line voltage. 55mV), 4 Electro-Harmonix 6SN7EH gold pins and 2 JJ Electronic ECC803 S gold pins tubes. In these calculations, 5% of the cathode current is assumed to be screen current. This product is suitable for EL34,KT88,6L6,6V6,5881,6550,KT66,KT100,KT120,7027 The product measures the cathode current of the power tube for bias reading (at low voltage side of the tubes ). kt120 plate voltage, dc tetrode triode grid 2 voltage, dc tung-sol continued from previous page maximum ratings design maximum values - see eia standard rs-239 volts volts volts volts volts watts watts ma ma ohms ohms celsius volts volts volts ma ma rna/v ohms watts percent 850 650 650 600 -200 60 8. DC Analysis: (1) Treat the capacitor as an open-circuit since its reactance (1/ jwC)= ¥ for DC ( = 0). grids of the KT150/KT120 output tubes through a pair of coupling capacitors that provide low frequency loop-gain stability. The relationship between bias voltage and idle current depends on the tube both the tube number and the individual tube which is why bias gets adjusted. Withous this negative bias the tube will conduct its full possible current and burn up very fast. The new porthole style bias meter and simply beveled face plate have a clarity of design that escaped the fussier XA200. All this with no global negative feedback. Crossover Roll-Off. Youll just have to do a little math to be sure the tubes are running safely. Each power tube of the Challenger 250 is controlled by the Auto Bias Regulator, and you don’t have to adjust the bias manually and can enjoy the music as you like. For the M125 with KT88 power tubes, we recommend a bias level of 0. Use this tool at your own Risk. The Bob Carver Crimson 275 has been making customers happy since its release late last year. The beta and Vd transistor parameters, can be measured, or gathered from a data sheet. Youll just have to do a little math to be sure the tubes are running safely. It's suitable for EL34 KT88 6L6 6CA7 6V6 5881 6550 KT66 KT100 KT120. You will see claims of as high as 100 watts from a pair of KT120's. Cheap valve tube amplifier, Buy Directly from China Suppliers:Douk Audio HiFi Dual Bias Current Probes Tester Meter for EL34 KT88 6L6 6V6 6550 Vacuum Valve Tube Amplifier Enjoy Free Shipping Worldwide! Limited Time Sale Easy Return. Due to the high voltage in the circuit, biasing an 845 / 805 or 211 amp improperly may expose you to lethal high voltage causing instant death. POWER REQUIREMENTS 100-125VAC 60 Hz (200-250VAC 50Hz) 300 watts at rated output, 500 watts maximum, 200 watts at "idle". Audio Research 610T (NEW KT120's) R 600,000. 1pcs T3 Tester. - User bias control has been used for bias adjustment and two meters have been added to the front plate to allow you to monitor bias with ease. Audio Research has added a new flagship, tube-based mono-block amplifier to its Reference Series. Reply to this topic;. THE CHAMP CBA-200/200 (8 x KT88) STEREO AMPLIFIER. The claim is for 45 watts of class "A" power (the circuit uses a constant current source output stage) at less than 2%. The larger octal 6550 to KT120 allow a higher idle bias Ia and Ig2, and thus there will be more initial class A power than for EL34. Since its production ceased in the early 1980s, the Genalex Gold Lion KT88 has become expensive and hard to find. Visually, the Reference 750 is a monolithic tower design, finished with monochromatic panels for a clean, contemporary appearance. After extensive research and engineering, New Sensor Corp. 32-600ohm headphone output 4. Generally speaking (in my experience) less expensive Chinese amplifiers tend to fitted with power transformers that are just barely adequate, so I wouldn't recommend running them.
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