Kt88 Bias Chart

Chart rolls easily no visible date. The new Taylor Tubes 572B is virtually an exact copy (both mechanical & electrical) of the original Cetron 572B/T160L tube. Plate Voltage mA: Calculate Plate Dissipation Based On Plate Voltage And Cathode Current Readings. These are the older cousins of today's MC-275s, which Mac has just re-introduced as a set with a 60th aniversary C-22 preamp. If you need an analyzer which can test KT88, KT120 and KT150 and many others then this is One of the finest tube analyzers ever made. The rig as far as the power supply is concerned was solid stated and the audio driver transformer was removed in favor of a phase splitter. Single Ended 2 x 8 Watt Class "A" (KT88) Uses push-pull 6SN7, then KT88. Esoteric A-100 Modello celebrativo 25 anni Finale di potenza stereo a valvole in push-pull. 42 mV is within the bias range for 6550s. stick free operation and make sure the roll chart works as it should Bias voltage checked and set to spec. EL34 KT88 5881 6L6 KT66 6550 Vacuum Tube Tester Amplifier Bias Current AK985 T1. The output transformer as an impedance matching device, works on the principal of reflected load. thetubestore. Marshall had to go with other tubes, like the 6550 or KT77 (and then even back to the good old 6L6). The numbers here are WATTS at various frequencies. Have you ever wonder what the difference is between each of the 6l6 tubes, have a quick look at this chart to help you see what the differences are as it just might help you choose. This is possible because these products have special hardware that. If you have not been trained to work with high voltage then have an amp technician adjust the amp's bias. balance potentiometers between KT88/6550's should be set in the mid-position. Single-ended EL34 amps are fairly rare in the guitar world, for a couple reasons (one being SE amps are usually designed to be less powerful so it makes sense to use a smaller tube, and also output transformer for SE are much heavier and expensive so the smaller the "better"). The 6L6, 7581A, 6V6, 6550, EL34, 5881, KT66, KT88, KT90, KT100, etc. Abstract: 5881 5881 tube tube 5881 tung-sol 5881 6l6 ultralinear 6L6G tube RL 1962 triode push-pull circuit. A better conversion would offered by a 180-ohm resistor, which would set an idle current of 100mA through the output tube and offer a conversion ratio of 55mA per input. The practice studio (CPE Sound in Chicago) where I played this amp is known for their great amps and very good tech, but he wasn't around to ask about it. com over the years. 95; Back in the late 50s-early 60s, Harman Kardon manufactured a 60-watt push-pull tube powerhouse called the Citation II. AND has several Western Electric tubes types right on the chart! 300A/B, 101L, 102L, 396A, and 417A! Will also test most common audio tubes like 6CA7, 6L6, 6SN7, KT88, 7247, 12AX, AU, AT, 7247, 7199,7355, 7591 and 7868 (with adapter). They made the Marshall amps sound different. The chart below compares the distortion ratio at 50Hz of two mic preamps: a Dbx 386 and an AEA TRP. Use this as a guide for setting your bias. It's the ultimate 100-watt plexi-style amplifier with maximum flexibility, maximum functionality and zero compromise in components, signal purity, and tone. All these links open in a new browser window so that you can return quickly to this page without having to reload. He is the author of The Guitar Amp Handbook, The British Amp Invasion, Guitar Effects Pedals, The Fender Telecaster, The Gibson Les Paul, and a dozen other books, in addition to being a regular contributor to several prominent guitar magazines. The other tester we use is a New London Instruments Model 901A Transconductance Analyzer. The 10K (R1) biases the tubes to cut off in standby receive mode. The Official Blackstar Amplification site, featuring Guitar Amplifiers, Guitar Amps, Effects Pedals, Merchandise, Dealers, Videos, Artist News. Not to be outdone, Sylvania introduced fat-bottled 6CA7 in US soon after. Line Transformers. Biasing an amp requires some knowledge of tube amp circuits and experience with high voltage. Fi 2a3 Schematic. 50 volts over a 10 ohm resistor on each tube. The bias should be about 1,5 Volts, meaning that these resistors should be of 1,5 Ω each. Power Tubes - 6V6S STR 417 Slovokian - Matched Pair. Determining the required value. HICKOK,TUBE DATA ROLL CHART. Click here to buy complete sets of tubes for your Z amps from The Tube Store. Marshall 200 Amp, 200W head. KT66 EQUIVALENT = KT8C GEC (England) It is a beam power tube almost identical to the KT66 (made by the same company) EXCEPT that is has a 5 pin british type ceramic base and a top cap anode connection. I've had amps with 6L6, 6V6, and (IIRC) 6BM8 (in an oddball Univox), and played through lots of 6V6, 6L6, EL84 and EL34 amps. I bias the amps while playing them to find the swet spot with whatever particular set of tubes is in the amp. Working early 60's MONO Tube Amp ~ Plug-n-Play ! MCS 3865 integrated amplifier *SERVICED* 100 % working. It considers both reactive loads and resistive load. Solid state rectifier. In the case of this amp with EL34's I would personally bias the power tubes around 30 mA. So that's quite a big difference. When using multiple speaker cabinets refer to the back panel Speaker chart for the proper Impedance Selector position. The computer interface (Top Right) is a “Brainbox” US-159 isolated USB to RS232 interface, providing a galvanic-ally isolated USB connection to my PC. 2A N/A 26KV 0. The sound was reproduced through a 1971 Marshal cabinet with 4 Celestion G12M "greenback" speakers. Since even tubes of the same make and model can sound different, I find that is the best way to go to get the tone I am after. The first and foremost is not to set the bias current so high as to exceed plate dissipation at any portion of the tubes operation, as indicated by that nice warm red glow of melting plates and the sound of a cash register ringing up a new set. 95 or factory-wired for $229. 9A heater current draw per tube, but when you switch to 6CA7 or KT88 the heater current draw is 1. Tung-Sol KT120 Super cool KT88 variant made by New Sensor in Russia. Environmental Protection Agency 401 M Street, S. Maybe even turn it up, it depends on how you like it really. 036 or 36 milliamps Most 50 and 100 watt amps using these tubes will have between 450 to 480 plate volts so even if you do not measure your plate voltage you will find that a setting between 35 to. If you want to compare only two tubes, you can input “2” for the C and D tube to hide tube C and tube D. The KT88 fits a standard eight-pin octal socket and has similar pinout and applications as the 6L6 and EL34. They were in production up to 1974. This calculator is for a single tube. Go here to see how to hook up the rectifier. Available immediately. KT120 TUNG-SOL. Groove Tubes Cross Reference Chart Groove Tubes Part Number Original Part Number GT-6L6B Sovtek 5881WXT GT-6L6S JJ 6L6GC GT-E34LS JJ E34L GT-EL34R Electro-Harmonix EL34. I played through a '70's V4B with KT88's last night. Latest: Hello from S. ) will change optimum plate to plate load impedance. We have found the Surgical Steel to be a stellar pedal platform for 6 string guitar, as it's high headroom and near endless sustain offers the perfect canvas for a variety of effects pedal configurations. d = Diode Unit. AMP SPECIAL LANEY CUB 12H LANEY CUBHEAD CUB 12H & CUBCAB and KT88separate power amp to sculpt Back it’s KT88 to sculpt your sounds. X̅ and R chart (858 words) exact match in snippet view article find links to article control-chart setup and A2, D3, and D4 are sample size-specific anti-biasing constants. 5 watts So, 24. Neuroscientific research has been obtaining consistent. The power amp can be equipped with2 EL34, 6550, 6L6 or KT88 tubes and has a power output of 50 or 100 Watts. In the case of this amp with EL34's I would personally bias the power tubes around 30 mA. Some of the new prod kt88's pull a boatload of current to power the heaters. 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. Model 86A; Model 87A; Model 142A. This holy grail of vintage combos has been used by Neil Young, Mike Campbell, Rich Robinson, Mark Knopfler, Billy Gibbons, and countless others. The KT88 / KT66 /6550 Directory. I am just looking for an explanation as to why the bias calculator numbers for KT88 tubes seem so high - compared to other common tubes. Current tube line up October-2019 Carmen Ghia. 7mA 88mA 3B2 25KV 1. 09% at just before clipping (82 watts each at 8 ohms) (Of course Woody had tweaked the bias reading on the regular service bench in the back of the. A Tale of Two Bias Settings. An American tube that has the same octal base as a 6V6 - and is a REAL PENTODE is the 6K6, and it requires about the same signal/drive/grid voltage to be driven to full power as a 6V6 - they can be used in lower voltage cathode biased (<300) amps with out any change of bias, etc. We agreed that I’d throw a few of my own tubes, including the Tung-Sol EL34B and Shuguang 6CA7-Zs I purchased from thetubestore. There is a lot of discussion on the black magic of setting the bias on the output valves in your amp. When Jon Esau of www. Full text of "Practical Electronics 1966 August" See other formats. HICKOK,TUBE DATA ROLL CHART. Aa04-p-sb315346-34 For - $288. The Electro-Harmonix 12AT7 preamp vacuum tube presents a clear, uncolored tonality with a very strong amount of signal gain. TABLE OF CONTENTS Please read these important safety instructions before operating this equipment. Because of our tradition of supplying the highest quality tubes, we are. Topic - Quicksilver KT88 blowing fuses/possibly power tubes-could a bad 5AR4 rectifier cause this? - padreken 11:19:21 02/12/10. This is possible because these products have special hardware that. Since even tubes of the same make and model can sound different, I find that is the best way to go to get the tone I am after. Should you be part of the audiophile world and need a second system, or if you are a current Naim owner wondering if the Qb passes muster, the answer is “without. I decided to build a tube amp for the fun. It is a single ended class A amplifier and features a Custom All Tube Guitar Amp Cascode 12ax7 Push Pull 6v6. Full text of "BK: B&K 700 707 1975 tube chart" See other formats. We have researched the proper grades to get the bias right where is should be with no bias mod. The sound was reproduced through a 1971 Marshal cabinet with 4 Celestion G12M "greenback" speakers. By using a very high value grid resistor and a coupling capacitor from the previous stage, stray electrons from the space charge surrounding the cathode are collected by the grid, and cause a voltage to appear. The EH 12AT7 is a good choice for reverb driver, line stage, and phase inverter positions. All elements with charts (e. Due to the high current and power capability of these tubes, it is very important that the KT88 tubes are well matched. It measures 12. Update December 3rd 2019: Added example valves Type 80, ATP4, 6V6G and 6SQ7. KT66 EQUIVALENT = KT8C GEC (England) It is a beam power tube almost identical to the KT66 (made by the same company) EXCEPT that is has a 5 pin british type ceramic base and a top cap anode connection. 8 Power Supply page. Tubes compatibility / Bias values Bellow you will find a bias chart for the most common compatible tubes for integre4. For this build, I will take this trade-off and save myself the complication of extra bias voltages or power supplies in fixed bias approaches. Marshall DSL40CR. Looking for a Tube not listed? If you can't find it, We'll find it for you! Email us at worldtubecompany @earthlink. TABLE OF CONTENTS Please read these important safety instructions before operating this equipment. We specialize in amplifier repair and guitar amplifier modification of vintage, hand wired tube amplifiers. An amplifier tube controls the flow of electrons running through it. 5 watts divided by a plate voltage of 450v would = 0. Stemming from over 6 decades of innovation, the latest Dynaco amplifiers and preamps deliver music with the dynamics and excitement that is only possible when mixing chemicals inside a glass tube. We agreed that I’d throw a few of my own tubes, including the Tung-Sol EL34B and Shuguang 6CA7-Zs I purchased. The KT88 fits a standard eight-pin octal socket and has similar pinout and applications as the 6L6 and EL34. the chassis is setup for 4 6l6 tubes. The same process is true for EL34's , KT66, KT77, KT88, but the numbers will be different according to the maximum power the valve can handle. The terminology for electrical connections to human subjects is not universally agreed upon. and became quick competition for the USA made 6550 tube. How you operate the tubes (push-pull, push-pull parallel, ultra-linear, class, B+, bias, operating points, etc. Any Penthodo grid bias are less than Triodo's bias so please try to use any kind of driver. This method, along with *listening* to the tubes I am capable of doing. Single Ended 2 x 8 Watt Class "A" (KT88) Uses push-pull 6SN7, then KT88. E-I lamination: A flat transformer steel lamination composed of pairs of E-shaped and I shaped pieces. For example, let's assume the Bias Reading for "V6" reads "38mV," and the Bias Reading for tube "V4" reads "36mV. The output transformer as an impedance matching device, works on the principal of reflected load. 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-C, Cathode Current) 4. Amplifier and amplifier modification kits. A Wrong Way to The Top. AMP SPECIAL LANEY CUB 12H LANEY CUBHEAD CUB 12H & CUBCAB and KT88separate power amp to sculpt Back it’s KT88 to sculpt your sounds. 5V grid line and the 1. We stock KT88 tube sets that are precision matched. For a complete explanation of each column heading, refer to TM 11-6625-316-12. d = Diode Unit. stick free operation and make sure the roll chart works as it should Bias voltage checked and set to spec. In addition, we offer an array of new "select" Dynakit™ classic vacuum tube. This calculator is for a single tube. The setting is locked in place by the outer locking nut. 8 thoughts on “ Optimization of the 6V6 SE-UL ” Alexis Hernández on March 28, 2020 at 10:34 AM said: Gracias, Gracias Matt, excelente trabajo de laboratorio suficiente como para que Yo intente utilizar mis 6V6 GT que tengo por allí y otros 12AX7 que debo conseguir para el pre-Amp. EL84/6V6GT - 12W. Fi 2a3 Schematic. Overall, one of the best bands I have ever heard, and seen in concert!. Uberschall changes implemented after 8/16/04: Adjustable Loop send and Volume Cut function, Bias Test Points, Uberschall Power Amp Mod We have added a potentiometer for the effects loop send level, this gives two benefits. Of all the hundreds and hundreds of charts, the Model 9's were the only amps that had a flat line at the bottom of the chart with a notation about 20KHZ being ,08%, 1KHZ being. com over the years. or any other commonality for that matter. For one thing, your bias voltage is much bigger and so you have to factor that in if your B+ is already determined and you're using cathode bias. Rectifier Valves, GZ34, 5U4GB, EZ81, 5Y3, etc 27 Item(s) Show 10 20 50 100 All per page. Everything would look normal, but when I played reggae music through the amplifier, it would over heat and the plates of the KT88 would run red, especially when I played a mix from the great King Tubby’s that had subsonic drum and bass frequencies as well as razor sharp high frequencies I would have to re -bias the KT88 and make other changes. As mentioned, this amp uses KT88 output tubes. The award winning Cronus Magnum has garnered an enviable reputation in the high end audio world. Bias Calculator. I have seen 150k and 220k as well. There is a individual bias controls for each output tube as well as an AC balance control. Thanks to the many visitors who have scanned documents and donated images to. 9 15Aug Enhanced Distortion troubleshooting with more tips; Noted wiring of OT to Impedance switch. 100 Amplifiers, part 2 , 1945 – 54. The amp tech asked what I'd like the amp to be biased to. Increasing the cathode bias resistor is often necessary. The 5881 should break up earlier. The new KT120 has 50% more power than the KT88 tube. The middle projection or tongue of the E is placed through the center of a coil of wire, and the I placed at the end like this" EI" so the iron forms a complete magnetic path through the center and around the outside of the coil. Current tube line up October-2019 Carmen Ghia. The line-only integrated amp can also be supplied with an optional phono stage. 0A 1550V 300mA 1000mA 5AW4 3. another feature not found on most Hickok checkers. 95; Back in the late 50s-early 60s, Harman Kardon manufactured a 60-watt push-pull tube powerhouse called the Citation II. Also included in this comparison are direct substitutes for the 12AX7 including: ECC83, ECC803, 7025 and 5751. Because of our tradition of supplying the highest quality tubes, we are. The pentodes Hegeman chose were 12BY7 video pentodes. The data on this page reflects the approximate year that these amplifiers were made and not the actual dates of manufacture of the amplifier. For these cases consider the Tung Sol 6L6 STR valves instead. I had to make a 7dB change to get the HF/LF somewhat balanced back out. Apart from Craig's octupler (x8) ruminations , I have been looking at an end -driven hextupler (x6) which makes a bias supply a conventional doddle. BIOPAC uses a …. Trasformatori di output su specifica Esoteric. The ProLogue & DiaLogue One, Four, and Six amplifiers can use 6550 and KT88 tube types without any issues. KT88 - Kinkless Tetrode Power Tube - The Tubes that made Rock 'n' Roll - Power Amplification Tags: vale, poweramplification-marshall, stack, power, amplification Available in Plus Size T-Shirt. An amplifier tube controls the flow of electrons running through it. The KT88 audio tube is considered to be one of the best sounding power tubes for hifi tube audio amplifiers. For a quick test, inspect the tube for signs of damage and listen to the sound it makes. Musical details are very accurate with strong headroom dynamics. Just 1 volt difference in the bias voltage can make a difference of 10 or even more ma, of anode current. Using four KT88 power tubes, these amps were very powerfull, very loud and very expensive. Due to its enlarged bias current window, the SE can run not only with EL34, 6CA7, 6L6, KT66, KT77 or 5881 but also the higher-current 6550, KT88, KT90 or KT100. d = Diode Unit. Of course, there are the usual 6V6, 6L6, EL34 and EL84, but Bias Amp 2 adds additional tube models, the 6550 and KT88, which provide the drive for many classic amps. It has 100, 120, 220 and 240 Volt export primaries. ) will change optimum plate to plate load impedance. The monoblock MC611 Quad Balanced Power Amplifier produces 600 Watts of power - enough to satisfy nearly any loudspeaker. Power Tubes - EL34 STR 447 - Matched Pair. Tube Brand / Electrical Ratings. There is no provision to set the bias for and so there will be crossover distortion. Measuring Device For Bias Four octal socket adapters, For the control of the retirement, At 6L6GC, 6550, EL34, 6V6 GT, 5881, KT88, KT66, KT90, KT100, 7027A, With illuminated display, Made in Germany. Trasformatori di output su specifica Esoteric. A KT88 could have a power rating of 35 - 45 watts, which would make the calculation for 70% dissipation: So, 70% of 35 watts is 24. KT88 are not same sound getting if Maker is different. 91 23Nov15 Corrected connection to Bias supply from Rectifier from pin 8 to pin 6. They are scanned into my computer, all of the stray lines, dots, etc. You can actually plot tube curves on this device. hp = Heptode Unit. *Exception to this guideline: there are a few custom/one-off Peters amplifiers which are specifically meant for 6L6GC/5881/KT66 tubes (such as the Super Hawk). As mentioned, this amp uses KT88 output tubes. Abstract: 5881 5881 tube tube 5881 tung-sol 5881 6l6 ultralinear 6L6G tube RL 1962 triode push-pull circuit. Title: 6L6G 6L6 Author: Tung-Sol Subject: FP-2004-06-05 Created Date: 6/5/2004 11:41:47 PM. KT88's should work fine if the bias is adjusted for them. B iasing by negative grid voltage is highly inaccurate because the same grid voltage can produce drastically different plate currents in different tubes of the same type. ) will change optimum plate to plate load impedance. The data on this page reflects the approximate year that these amplifiers were made and not the actual dates of manufacture of the amplifier. thetubestore. Separate Rhythm and Lead channels with added footswitchable BOOST functions make the Tweaker 88 the decisive choice for live performance, studio or just plain rockin’ out. Of all the hundreds and hundreds of charts, the Model 9's were the only amps that had a flat line at the bottom of the chart with a notation about 20KHZ being ,08%, 1KHZ being. The 50Hz measurement was used for Lows, 700Hz for mids and 6kHz for highs. Last Update: Description. The KT88 fits a standard eight-pin octal socket and has similar pinout and applications as the 6L6 and EL34. WARNING: A tube amplifier chassis contains lethal high voltage--sometimes over 700 volts AC and 500 volts DC. Formed in 1994 with former TESLA equipment, Jan Jorgo started JJ manufacturing with just three tube types - EL84, EL34 and ECC83. This calculator uses the power equation. The line-only integrated amp can also be supplied with an optional phono stage. 807, 5881, el34, 6146b, 6550b, kt88 Notes: The above examples of possible combinations are to help you narrow down the choices of transformers for your favorite tube types. The practice studio (CPE Sound in Chicago) where I played this amp is known for their great amps and very good tech, but he wasn't around to ask about it. The author cames no responsibility for any information provided. 572B Matched Triple Set (3) Taylor Tubes. EL34 handled lots of power in a small envelope. Increasing the cathode bias resistor is often necessary. The award winning Cronus Magnum has garnered an enviable reputation in the high end audio world. For the tubes, I decided to use some KT88. One thing you also need to consider is the amount of current draw that they have. ive used rca black plate 6L6gc's (still have a pair that i use for recording or when it really matters) and they are fantastic but the big, deep, tight bottom end, lush textured mid range, and silky. Please see the substitutes at the top of the page for more details. Used to build model 6G15 stand alone reverbs, Re-Vibe's and pre-amps. BIOPAC uses a …. 5V grid line and the 1. The Bruiser is a heavy duty stereo tube amp designed to handle these types of speakers. - Maybe I should divide this "chart-calculator settings" by 2? But why?. 36W Voltage Chart EL84 V7 V8 EF86 V9 36W EF86 Voltage Chart Plexi 100 Watt EL34 HT Plexi 50 Lead JTM45 KT66 B+ TrainWreck Express PPIMV (tested on Twreck Xpress PPIMV 120V - 11/12/06) Bias For PPIMV 38-40 (tested on 18W tremolo 240V - 21/12/06) EZ81 18W Tremolo - Tremolo Off 18W TMB (tested on 18WTMB 240V - 15/01/07) B+ = OT CT = 328 OT CT. KT88: pdf Bold designators are close or identical, Italic designators are different ratings, different pinouts or different filament voltages. Just 1 volt difference in the bias voltage can make a difference of 10 or even more ma, of anode current. The KT88 audio tube is considered to be one of the best sounding power tubes for hifi tube audio amplifiers. Title: 6L6 Author: RCA Subject: FP-1999-02-28 Created Date: 2/24/2002 7:46:40 PM. Even at its attainable price, it outperforms other integrated amps costing many times more. The amp tech asked what I'd like the amp to be biased to. How to test KT88 tubes (Last updated: 14-Mär-2017 17:41) The KT88 tubes is a curious tube. Maximum power input to PT = 444. Dynaco is the very soul of high fidelity audio. Many articles have appeared regarding projects using one of the most sturdy, versatile, and trustworthy audio tubes ever made — the 6550. Jadis OR bias value for Mullard RL34 and KT88 help I just swapped my Gold Lion (reissue) KT88 tubes for Mullard EL34's and was vwery surprised that the volume was so much lower. t = Triode Unit. Tube type: ----Choose---- 6V6 EL84/6BQ5 5881 EL34 KT66 6L6GC KT88/6550. The 12AX7 is a 9-pin miniature, high-mu, twin triode. Amplifier and amplifier modification kits. Photograph of a rare Marshall 200 head a. All of the tubes listed above have their cathodes on pin EIGHT, which will be grounded to the chassis. 35W with 6CA7/EL34 fixed bias; 50W with 6550/KT88 fixed bias; Univox. The only KT88 settings that I've been able find is on the 666-05 chart, but the pin settings are incorrect and the grid & plate settings appear way off. About 50 ma is right when in an ST-70 which is. Setting the Bias. This amp does not have user-adjustable bias settings, a common feature of most all Mac amps. In general, the KT88 tube has a magical mid-range similar to the smaller EL34 tube , but with low and high end extremes that reach much further. cv5220, kt88, kt88s, kt88sc, kt90 Warning: Substitutes are given as a guide only - please refer to original manufacturers data sheets to ensure that a substitute is safe and appropriate for your application. Higher powers are obtainable with either very large power valves, or by using multiple valves in parallel, but beyond about 15W it is usual to use. What are you talking about? We are talking a EL34 to KT77 switch. Use this tool at your own Risk. MCS 3865 integrated amplifier *SERVICED* 100 % working. The KT88 audio tube is considered to be one of the best sounding power tubes for hifi tube audio amplifiers. Typically this is negative 12volts for a EL84, -35 for a EL34 and -50 volts for a KT 88. 09% at just before clipping (82 watts each at 8 ohms) (Of course Woody had tweaked the bias reading on the regular service bench in the back of the. METHODOLOGY FOR XRF PERFORMANCE CHARACTERISTIC SHEETS Technical Branch National Program Chemicals Division Office of Pollution Prevention and Toxics Office of Prevention, Pesticides, and Toxic Substances U. All elements with charts (e. 5 watts So, 24. There is a lot of discussion on the black magic of setting the bias on the output valves in your amp. They are capable of delivering 100 watts per pair and this is the typical application in which they are applied in the TWO/NINETY/TWO and TWENTY ONE FIFTY power amps and SIG:X head. Bias Vdc for 8 x adjust pots for fixed bias = 135Vdc x 0. We agreed that I'd throw a few of my own tubes, including the Tung-Sol EL34B and Shuguang 6CA7-Zs I purchased. with 50 volt fixed bias output, a 35 watt output transformer, 6L6 power tubes, bigger filter caps and a fixed bias circuit. 1 - Gm test but with Gm signal disconnected from the grid, only bias remaining : no Gm reading with 6L6GC, KT88, that's normal, BUT reading at circa 4000-4500 on 6000 range with the 7x 300B, in REVERSE meter switch selection. Each amp had 15 KT88 tubes, two chassis connected by a thick umbilical, granite bases, big glass meters and immense output transformers on the back. They made the Marshall amps sound different. Bias Settings For Safe Plate Dissipation - Class AB 70% Class A 90%. Note that some real amps are “spitty” in nature due to PI bias shifting, i. And many European tube manufacturers soon started manufacturing EL34. The following tube tester manuals are available at any time. In the JD-1000P Level-2 mod we do the following [retrofit $1,000 + frt to your amp, New modified units are $2,790 + frt]:. Line Transformers. 70) Posted by The Bear on 2009-01-21, 16:27:18 (71. You check the bias on the EL34s, swap in the KT77s and adjust to match, or a little hotter if you want. Full text of "BK: B&K 700 707 1975 tube chart" See other formats. This amp does not have user-adjustable bias settings, a common feature of most all Mac amps. 300B Triode Vacuum Tube Comparison Review The Cardinal is a self bias unit with the B+ set at 400 volts with a median current of 65-75 milliamps. All the major brands are covered. Insert the black and red ends into the proper test points and note the reading on your multimeter. This new electrode is called the screen or shield. Kessler is not exaggerating. DC measurements : NEVER run the high voltage power supply line without tubes as a load , this will damage the Black Gates and the Siemens , always use the stand bye switch or disconnect. Chart properties provide many ways to customize chart appearance. Twin Tube Amp Bias Matching Meter 6L6 EL34 KT88 6550. This is a story about the making of that monster. EL34 KT88 5881 6L6 KT66 6550 Vacuum Tube Tester Amplifier Bias Current AK985 T1. The chart below compares the distortion ratio at 50Hz of two mic preamps: a Dbx 386 and an AEA TRP. Power Tubes - 6L6 STR 441 - Matched Pair. High-mu Power Triode for use in Class AB2, Class B, Class C RF, and audio amplifiers. The 6L6GC tube is a 30W valve. Also, the KT150s tend to bias hotter (a higher bias current for any given set of operating conditions) than KT-88s so you need to be sure you can adjust the bias properly - bias that can't be adjusted properly is not a defect in the tube. thetubestore. Small Signal Audio Design is a unique guide to the design of high-quality circuitry for preamplifiers, mixing consoles, and a host of other signal-processing devices. My recommended bias measurement method is the "Output Transformer Resistance Method. Amplifiers of this type, such as Marshall amplifiers, are used in a range of genres, including hard rock, metal (though they are often boosted with a pedal for more gain), and punk. hx = Hexode Unit. The numbers here are WATTS at various frequencies. The amp can also handle the even more powerful KT150. Dynaco™ replacement parts & vacuum tube audio amplifier kits. This tester differs substantially from the 539B & C and unfortunately the settings from the B&C don't work for the 539A. T are many charts online that will give you the proper range of current for your tubes. Use a fine flat-head adjustment screwdriver (we recommend a 2. Have you ever wonder what the difference is between each of the 6l6 tubes, have a quick look at this chart to help you see what the differences are as it just might help you choose. EL34 became very popular in audio amplification. Last Update: Description. Original power tubes in this amp are 6CA7 but the owner likes to use KT88 and use it for bass. In German: Single Ended: 48. Should you be part of the audiophile world and need a second system, or if you are a current Naim owner wondering if the Qb passes muster, the answer is “without. 1: RE: Jackson 648A Tester Settings (10. 23 Watts For the JJ 5881's 14 watts for 6V6's 35 watts for KT88's and 6550's Example: 25 watts divided by 480 =. I do know the bias current requirements for the 6550's, KT88's & KT90's when I was using Manley monoblocks, which required individual biasing. Choosing between EL34, KT88, or KT120 tubes. I am just looking for an explanation as to why the bias calculator numbers for KT88 tubes seem so high - compared to other common tubes. Total maximum power to amp from all Secondary windings of PT = 399W + 120W + 2. How to test KT88 tubes (Last updated: 14-Mär-2017 17:41) The KT88 tubes is a curious tube. The only KT88 settings that I've been able find is on the 666-05 chart, but the pin settings are incorrect and the grid & plate settings appear way off. bias resistor to 47K from 22K in PSU HiV Sec. 1: Easy SET: just disconnect the input to one KT88: this will damage nothing unless your KT88's are DC coupled. It shows 813's but the KT88, 807, almost any tetrode or beam tube will do. Abbreviations. 6l6 Amplifier Circuit 5E3 Deluxe Amplifier Modifications. A Stock 3444 can not read these tubes for plate current, this o. The Ultra Linear/Triode switch on the amp allows switching from 80 watts to 40 watts of triode sound. For these cases consider the Tung Sol 6L6 STR valves instead. This is possible because these products have special hardware that. THE GROOVE TUBES RATING SYSTEM. 8 thoughts on “ Optimization of the 6V6 SE-UL ” Alexis Hernández on March 28, 2020 at 10:34 AM said: Gracias, Gracias Matt, excelente trabajo de laboratorio suficiente como para que Yo intente utilizar mis 6V6 GT que tengo por allí y otros 12AX7 que debo conseguir para el pre-Amp. hp = Heptode Unit. In the case of this amp with EL34's I would personally bias the power tubes around 30 mA. 1 bias supply KT88 22K, 1/2W 71-RN65D-F-22. "A receiver tube is a consumer-grade tube, so it's got to be cheap," Charley Hansen says of tubes made for home. Speaker: 13. PI BIAS SHIFT – Controls the amount of phase inverter bias shift. In these calculations, 5% of the cathode current is assumed to be screen current. Speaker: 13. DIY KT88 Push-Pull Monoblock Tube Amp Kit - 30 November 2009 KIT A build and review of the Odd Block KT88 Series 1 Tube Amp Kits. proper tube tester calibration, hickok tube testers, tube tester restoration, restoring tube testers. We stock original Marshall switches and logs, cab feet, ohms selectors and voltage seletors. Tube type: ----Choose---- 6V6 EL84/6BQ5 5881 EL34 KT66 6L6GC KT88/6550. On the one hand, we always told not so mistreat a tube. QUAD TUBE AMP Bias Meter 6L6 El34 KT88 Probe with PLATE VOLTAGE MEASUREMENT - $69. 8417, KT77, KT66, 6L6-GC, 58810utput tubes, using with triode connected output tubes 5. I used the Sovtek KT88/ 6550's and they worked great without any mods whatever in a Johnson Ranger. The 50Hz measurement was used for Lows, 700Hz for mids and 6kHz for highs. A super value compared with TV-10 and TV-7. a push-pull amp. Manufacturer's data is available for triode operation of some popular types of tetrode, pentode and beam power tubes such as EL34/6CA7, 6V6GT, KT66, KT88, 807, 6146. This modification will allow use of either 8417, KT88 or 6550 valves & possibly EL34. Discussion in 'Audio Hardware' started by Brian I run EL34's but I am not too fond of KT88's. Page 14 Power On The BIAS ADJustments were made during the final Input Switch testing of the MC2000 at the factory. This calculator uses the power equation. 6CA7 was not a copy of EL34, it was a design of its own. Consult an amp tech if you are unsure. Introduction. Whichever way you choose to set the impedance for these tubes, use the same bias range in the chart for these 3 tube types (treat them all as 6L6GC). The new KT120 has 50% more power than the KT88 tube. Vacuum tubes are an older technology not often used today, but they still show up in some amplifiers and other devices. Power Tubes - KT-88 STR 488 - Matched Pair. We stock KT88 tube sets that are precision matched. Uses a bridge rectifier. When Jon Esau of www. Troubleshooting Procedures 7. Musical details are very accurate with strong headroom dynamics. EEG sensors are able to pick up these tiny signals from the scalp surface. 1: RE: Jackson 648A Tester Settings (10. KT88 (6550 equivalent) Genalex GOLD LION reissue, new productionMATCHED PAIR: Looks and sounds like the 1960s vintage Genalex Gold Lion KT88, one of the most famous vintage power tubes in the world. The indicator can be arranged to provide audible and/or visual indication of system performance, function, status, or any other desired indication. hx = Hexode Unit. 0: 12AX7, 6V6: 231: DIY Plasma-Tweeter: Looks better than the other one. proper tube tester calibration, hickok tube testers, tube tester restoration, restoring tube testers. Studer A810 Archival half track IEC EQ tape machine. How to Test Vacuum Tubes. How to test KT88 tubes (Last updated: 14-Mär-2017 17:41) The KT88 tubes is a curious tube. mike Mike's Corner, Vintage Restorations 6sn7, amp, amplifier, bias, capacitor, dynaco, kt88, mark iii, modification, monoblock, power, restoration, upgrade Recently we had an original owner pair of Dynaco Mark III amplifiers brought to us for restoration and modification. 23 Watts For the JJ 5881's 14 watts for 6V6's 35 watts for KT88's and 6550's Example: 25 watts divided by 480 =. Choose from names like RCA, Mullard, GE, Philips, Amperex, SED (Svetlana Electron Devices), Sovtek, JJ, Tung Sol (NOS and Reissue) and Electro Harmonix. 1-16 of 269 results for "vacuum tube amplifier kit" Skip to main search results Amazon Prime. If you have not been trained to work with high voltage then have an amp technician adjust the amp's bias. There is a individual bias controls for each output tube as well as an AC balance control. That would mean 54 mA per tube. Have you ever wonder what the difference is between each of the 6l6 tubes, have a quick look at this chart to help you see what the differences are as it just might help you choose. DC measurements : NEVER run the high voltage power supply line without tubes as a load , this will damage the Black Gates and the Siemens , always use the stand bye switch or disconnect. 0: 6SN7 (2), KT88 (2) 230: Audio Amplifier with transistor [In Dutch] Schematic Only. Click here to buy complete sets of tubes for your Z amps from The Tube Store. AmpliTube recreates the entire guitar/bass signal chain from instrument to recording device, and does so in a very realistic and intuitive way. This holy grail of vintage combos has been used by Neil Young, Mike Campbell, Rich Robinson, Mark Knopfler, Billy Gibbons, and countless others. Rebranded tubes just means that they will be more expensive. com - Your online source for audio vacuum tubes. This is one of the most affordable tools to measure an amp's bias, and see how two tubes perform at the same time. In our case, we have just over 200V B+ to work with and we want to use a self-bias scheme, so our grid/bias voltage (the grid lines) plus the anode voltage (the horizontal axis) should add to about. Congratulations on your purchase of the Ampeg V-4B 100W all-tube bass head. WEBER BIAS SETTINGS. BE A SMART CONSUMER Those products made in China might be cheaper, but the LED type meter display used a lot of power. To create this article, 21 people, some anonymous, worked to edit and improve it over time. The computer interface (Top Right) is a “Brainbox” US-159 isolated USB to RS232 interface, providing a galvanic-ally isolated USB connection to my PC. Many folks use a bias probe incorrectly. Covering a wide range of tubes including 12AX7, 12AT7, 12AU7, EL84, 6L6, EL34, 6V6, KT88, KT77, 300B, 2A3, 6CA7 and the list goes on. (Check out the TEA2025 datasheet for more information on that) On the input side, you should use a dual potentiometer. Full text of "Practical Electronics 1966 August" See other formats. electron Tube Data sheets - Type index. T are many charts online that will give you the proper range of current for your tubes. An amplifier tube controls the flow of electrons running through it. What is Bias? Bias voltage is the voltage difference between a tube's cathode and control grid. “Ground” and “reference” are often used interchangeably. 35W with 6CA7/EL34 fixed bias; 50W with 6550/KT88 fixed bias; Univox. com offered a set of five EL34-type tubes for review (JJ KT77; JJ EL34 II; Svetlana EL34; Genalex Gold Lion KT77 and Mullard EL34) I jumped at the opportunity. Designed for endurance and longevity for application in the audio industry. ) will change optimum plate load impedance. EL34 Review Chart (View our complete selection of EL34 / 6CA7 / KT77 vacuum tubes) Test Amps: 1973 Marshall Super Lead model 1959: This amp is completely stock using NOS pre-amp tubes. Even at its attainable price, it outperforms other integrated amps costing many times more. You check the bias on the EL34s, swap in the KT77s and adjust to match, or a little hotter if you want. I've had amps with 6L6, 6V6, and (IIRC) 6BM8 (in an oddball Univox), and played through lots of 6V6, 6L6, EL84 and EL34 amps. You can actually plot tube curves on this device. a push-pull amp. The Tube Amp Schematics Library. The 10K (R1) biases the tubes to cut off in standby receive mode. Amplifier and amplifier modification kits. Not to be outdone, Sylvania introduced fat-bottled 6CA7 in US soon after. thetubestore. “A receiver tube is a consumer-grade tube, so it’s got to be cheap,” Charley Hansen says of tubes made for home. 2 POWER TUBE GRID BIAS. The negative grid voltage method: This method involves measuring the DC voltage on the grid of the output tubes, and setting it to a recommended value. 00 * Tweed One-5, 5F1 Style Amp-Kit Tweed One-5, 5F1 From €315. The OP’s amp can accommodate either an El34 or Kt88 tubes and these aforementioned bias setting are also quoted in the OP. An amplifier tube controls the flow of electrons running through it. Power Tubes - 6L6 STR 445 - Matched Pair. Thanks to the many visitors who have scanned documents and donated images to. Found 148 records in Search of Tubes Asylum. The Bruiser is a heavy duty stereo tube amp designed to handle these types of speakers. Stemming from over 6 decades of innovation, the latest Dynaco amplifiers and preamps deliver music with the dynamics and excitement that is only possible when mixing chemicals inside a glass tube. 9 15Aug Enhanced Distortion troubleshooting with more tips; Noted wiring of OT to Impedance switch. This Custom Special amp head is a mid-year 1967 model which is a mix of '67 and '68 models. Electron tubes are almost outdated, but there was one time when the electron tube. Many articles have appeared regarding projects using one of the most sturdy, versatile, and trustworthy audio tubes ever made — the 6550. EL34 handled lots of power in a small envelope. the 2 tubes and set the current level to the value on the chart. The market expanded. Due to many requests by fans of our Tung-Sol line of tubes, the Tung-Sol EL84/6BQ5 has been reissued. QUAD TUBE AMP Bias Meter 6L6 El34 KT88 Probe with PLATE VOLTAGE MEASUREMENT - $69. 5 watts divided by a plate voltage of 450v would = 0. With an output of 300 Watts, it provides enough high power to drive even the most demanding loudspeaker. 36W Voltage Chart EL84 V7 V8 EF86 V9 36W EF86 Voltage Chart Plexi 100 Watt EL34 HT Plexi 50 Lead JTM45 KT66 B+ TrainWreck Express PPIMV (tested on Twreck Xpress PPIMV 120V - 11/12/06) Bias For PPIMV 38-40 (tested on 18W tremolo 240V - 21/12/06) EZ81 18W Tremolo - Tremolo Off 18W TMB (tested on 18WTMB 240V - 15/01/07) B+ = OT CT = 328 OT CT. Measuring Device For Bias Four octal socket adapters, For the control of the retirement, At 6L6GC, 6550, EL34, 6V6 GT, 5881, KT88, KT66, KT90, KT100, 7027A, With illuminated display, Made in Germany. When you care To have the MC2000 automatically turn On or Off The INPUT Switch allows selection of two different when a Control Center turns On or Off, rotate the to make BIAS ADJustments, please follow the steps input sensitivities. Should you be part of the audiophile world and need a second system, or if you are a current Naim owner wondering if the Qb passes muster, the answer is “without. Line Transformers. Input sensitivity 0. 06% and 20 HZ being. the chassis is setup for 4 6l6 tubes. EL34 Power Tube. Vintage amplifiers can take effects to the next level. Musical details are very accurate with strong headroom dynamics. How you operate the tubes (push-pull, push-pull parallel, ultra-linear, class, B+, bias, operating points, etc. When trying to bias them in an actual amp they differed as much as 8 mA in current draw. 495,-- SPIRIT III Integrated or Power amplifier; 2x55W Pentode or 2x35W. I don't know what's a good bias, but I suggested 44 mA, as that's lower than some 6550 bias settings I've seen online, and at the same time isn't very low. A full balance EQ section feeds a pair of ultra-linear connected KT88 power tubes. The author cames no responsibility for any information provided. They seem to bias very hot when you use them in place of a 6L6GC. Oscilloscope) have chart properties. Amplificatore a valvole - Italian DIY SE amp with EL34 or KT88 Amplification audiophile et DIY AWG to Metric Conversion Chart - For Self Bias- DIY Ultra-Fi. the "Pig" from 1967 (thanx to and courtesy of Jacques of www. The calculator will give you the bias current for each tube. Kt88's usually have 100k bias resistors for a pair. To help explain this, refer to figure 1 below. So that's quite a big difference. The other tester we use is a New London Instruments Model 901A Transconductance Analyzer. Full text of "Practical Electronics 1966 August" See other formats. I don't know if this is because of the tetrode instead of pentode design. Sound I am emphasizing again that my impression is based on SR1a which Aegir isn’t recommended to drive (even Jason mentioned so!). It has the choke of the '67 head with preamp. Some old radios had 3 batteries, Filament, Bias, and Plate supplies (yes a small horror then) The below radios use 75mA of filament current alone, 10 times what the transistor radio needs to operate. Class AB Power Amplifiers. It seems odd to me that I would have gone from a higher output tube (KT88) to a lower output tube (EL34) and the bias went from. So that's quite a big difference. At that time, I praised everything about the amp save for its excessive sweetness. In this article, the 6550 is used in a clean, sweet-sounding, single-ended design. In these calculations, 5% of the cathode current is assumed to be screen current. Electro-Harmonix owns 100% of the largest remaining vacuum factory in the world. The letters "CCW" in the BIAS column, under METER SETTING, represents "counter-clockwise. These are the older cousins of today's MC-275s, which Mac has just re-introduced as a set with a 60th aniversary C-22 preamp. Just 1 volt difference in the bias voltage can make a difference of 10 or even more ma, of anode current. 100 watts with two KT88 is also push-pull. The resistor value is determined based on design averages for plate voltage and current. are all easily biased with this method. Enter values in blue and click any Calculate button. The indicator can be arranged to provide audible and/or visual indication of system performance, function, status, or any other desired indication. A KT88 tube has a recommended bias at around 380mv-420mv. and sound very similar to EL84 - they only produce about %75 of. Tubes supplied by www. SPECS: (similar to KT66 specs) Heater Voltage: 6. Design your own custom Turret Board or Eyelet board. It has an international octal base (indicated by the '3' in the part number) and is found mainly in the final output stages of audio amplification circuits and was designed to be suitable as a series regulator by virtue of its high permissible voltage between heater and cathode and other parameters. If you have an amp which uses power tubes which are not listed above, you will need to consult a spec manual (the RCA RC-30 Receiving Tube Manual is one of the best) for the basing, and adjust. All elements with charts (e. I think it's the greatest amp ever made, next to the Ampeg Gemini I. The 12 VDC PS powers the input/output and bias relays. Oscilloscope) have chart properties. If you need an analyzer which can test KT88, KT120 and KT150 and many others then this is One of the finest tube analyzers ever made. As musical tastes transformed from big band to swing to jump. 10 Revamped the Start-Up procedure; added cathode bias section 1. The KT120 is probably the best all around tube out of all of them but the others have their merits. AMPLIFIER KT88 SERIES ORION II Integrated amplifier; 2x50W Pentode or 2x30W Triode - switchable, 4x Ayon KT88s, 3x12AU7, 0dB NFB, 3 x Line-In, 1x USB-In, 1x Pre out, 1 x Direct in, RC, Auto-Fixed-Bias system& Tube test program, PPP; N E W € 2. Tube tester data roll chart. Self-bias output tubes require no bias adjustments, and configured for Ultralinear operation; if you have a KT88 based amp, buy the Sophia Blue Bottle 88s) "Roll With Me" reached 10 and "Always The Last To Know" which hit 30 on the US charts. Line Transformers. 50L6 : 50V *. Marshall Amp Parts for marshall amps. Given below is the tube amp bias calculator to find the bias in ampere or milliampere (mA or A). Please see the substitutes at the top of the page for more details. In this old Marshall bias chart for a 2203 with 6550s, it appears to me to be suggesting a bias of 51 mA per tube. V6-V9- 6L6GC (50/100 Watt) and KT88 (150 Watt) Output Each fine production tube is tested and matched to our exacting specifications. The purpose of this KT88 / KT66 /6550 / KT90 / KT120 page is to give an overview about what KT66, KT88. Topic - Quicksilver KT88 blowing fuses/possibly power tubes-could a bad 5AR4 rectifier cause this? - padreken 11:19:21 02/12/10. Tube Bias Calculator Instructions & Help. 8 thoughts on “ Optimization of the 6V6 SE-UL ” Alexis Hernández on March 28, 2020 at 10:34 AM said: Gracias, Gracias Matt, excelente trabajo de laboratorio suficiente como para que Yo intente utilizar mis 6V6 GT que tengo por allí y otros 12AX7 que debo conseguir para el pre-Amp. hp = Heptode Unit. The Electro-Harmonix 12AT7 preamp vacuum tube presents a clear, uncolored tonality with a very strong amount of signal gain. BIOPAC uses a …. ~ Schematic Diagrams & Service Information ~ T he following is a list of Valve and some classic transistor equipment schematic diagrams and some service information T o increase clarity and or reduce the file sizes some have been traced redrawn and output in Adobe Acrobat pdf format. DIY KT88 Push-Pull Monoblock Tube Amp Kit - 30 November 2009 KIT A build and review of the Odd Block KT88 Series 1 Tube Amp Kits. i for now want to use a 12ax7 since there is a 9 pin socket already. Tube amp Bias Calculator. X̅ and R chart (858 words) exact match in snippet view article find links to article control-chart setup and A2, D3, and D4 are sample size-specific anti-biasing constants. In our case, we have just over 200V B+ to work with and we want to use a self-bias scheme, so our grid/bias voltage (the grid lines) plus the anode voltage (the horizontal axis) should add to about. The 50Hz measurement was used for Lows, 700Hz for mids and 6kHz for highs. This was a “Question of the Day” post from Max in Stanhope, PA. cleaned up and then printed on my Laserjet 5000 printer. the chassis is setup for 4 6l6 tubes. V6-V9- 6L6GC (50/100 Watt) and KT88 (150 Watt) Output Each fine production tube is tested and matched to our exacting specifications. KT88: pdf Bold designators are close or identical, Italic designators are different ratings, different pinouts or different filament voltages. But if the EL34 amp uses a lot of negative feedback and is fixed bias while the 6L6 amp has no feedback loop and is cathode biased the 6L6 might actually behave more like a traditional EL34 amp and vice versa. For example, judged according to plate characteristic curves 6L6 tubes generally overdrives harsher than a EL34 tubes. Bias Settings For Safe Plate Dissipation - Class AB 70% Class A 90%. a push-pull amp. The 102D’s are supposed to draw 1 Ampere through the series coupled heaters. This article has also been viewed 140,592 times. Dynaco™ replacement parts & vacuum tube audio amplifier kits. That would demand a supplied Voltage of 2V+2V+1,5V+1,5V = 7 V. I checked the bias and found it to be less than 10mv while the KT88's had been biased at 110mv. So back to push pulls, as EL34 and EL84 i allready made many before and the KT88 family is one of my favourites i choose for a KT88 design. The amplifier class is selected by biasing the control grid of the output tube into the range to select the appropriate conduction cycle. Class AB Power Amplifiers. The purpose of this KT88 / KT66 /6550 / KT90 / KT120 page is to give an overview about what KT66, KT88. Everyone please stay safe and we are filling orders daily. Power Tubes - KT-88 STR 488 - Matched Pair. , Bill Traylor (bozzy369) Username: bozzy369 Registered: 02-2008. Class A operation is often found in high-end audio, but less often in guitar and bass amplification. Abbreviations. The power amp can be equipped with2 EL34, 6550, 6L6 or KT88 tubes and has a power output of 50 or 100 Watts. later i might try a 6sl7 im not very familiar with those. When the. There is a 22V zener diode that regulates the voltage that powers the reverb and biases the preamp that needs to be taken into account. Class A operation is often found in high-end audio, but less often in guitar and bass amplification. My Marshalls are all biased a little differently. In our case, we have just over 200V B+ to work with and we want to use a self-bias scheme, so our grid/bias voltage (the grid lines) plus the anode voltage (the horizontal axis) should add to about. When trying to bias them in an actual amp they differed as much as 8 mA in current draw. The pin out is the same. The only KT88 settings that I've been able find is on the 666-05 chart, but the pin settings are incorrect and the grid & plate settings appear way off. Leaving the bias set to a 6L6GC setting and/or using the Tungsol 5881 in a high voltage amp with a solid-state rectifier, will likely cause problems and are not covered by warranty. Rectifier Tube - 5U4GB. 40 and the amp made my HF section a lot louder. For a complete explanation of each column heading, refer to TM 11-6625-316-12. Please be advised that, I will be out of town from 20 Oct 2010 to 29 Oct 2010 , hence no shipment will be made during this period. It has test points on the front of the amp to bias it with. Pat was blown away with the build quality on these amps, and looking at the plate voltage which was running at 780volts, thought it would be cool to put some KT88s in. The Tung-Sol EL84/6BQ5 was a popular OEM tube for American-made EL84/6BQ5 guitar amplifiers, such as those built by Gibson and Harmony. cv5220, kt88, kt88s, kt88sc, kt90 Warning: Substitutes are given as a guide only - please refer to original manufacturers data sheets to ensure that a substitute is safe and appropriate for your application. Medical, Plug-In Isolation, Autotransformers. Before insert KT88 check the bias voltage on grid setting the trimmer for the max negative voltage. A Tale of Two Bias Settings. Find the test points on your amplifier labeled V1, V2, etc. Marshall DSL40CR. KT88's or 6550 tubes will last longer in an ST-70 than EL34 tubes. 6CA7 - America's Answer. Plate Voltage mA: Calculate Plate Dissipation Based On Plate Voltage And Cathode Current Readings. How to Measure Bias. Designed for endurance and longevity for application in the audio industry. You can actually plot tube curves on this device. EL34 Review Chart (View our complete selection of EL34 / 6CA7 / KT77 vacuum tubes). - Maybe I should divide this "chart-calculator settings" by 2? But why?. Of all the hundreds and hundreds of charts, the Model 9's were the only amps that had a flat line at the bottom of the chart with a notation about 20KHZ being ,08%, 1KHZ being. I hope your tech had a schematic and didn't just install a bias pot willy-nilly. We agreed that I'd throw a few of my own tubes, including the Tung-Sol EL34B and Shuguang 6CA7-Zs I purchased. Bias Calculator. 6 POWER TUBE HARDNESS. Title: KT88 Author: M-O Valve Subject: JA-FP-2000-10-01 Created Date: 10/1/2000 7:35:29 PM. It considers both reactive loads and resistive load. The fixed bias output stage offers wonderful punch with a smooth break-up when pushed.