6v6 Plate Voltage

This was remarkable compared to other tubes available at that time, which required higher plate voltages and/or higher driving power for the same output. Like JJ' for example. The 6AQ5 is a lower power 6V6 in a 7 pin package used originally in car radios, and the 6L6 is an upgraded 6V6 with higher voltage and higher current. An obvious way to lower the voltage is to add a resistor in series with the heater supply. One of the Tungsol’s went bad and decided to red plate. That will tell us the total plate and screen current thru both 6v6s, and will also enable the plate (and screen) dissipation to be calculated. 5V4s are indirectly heated and take longer to conduct which means B+ takes a few more seconds to get going. Tellegen in 1926. Plate dissipation 14 W Grid no. There are however plate voltage limitations on the basic 6V6/6V6GT, the basic 6AQ5, and the 6005 of 250v. If the tube can handle 400 Plate volts, then in this amp it has to be at the limit, pushing it IMO. I fitted my Tremoverb with variable bias for the same reason - the bias is *really* cold in the Spongy and Tube Rectifier modes, much lower than what you're getting. I use RCA nos and have a couple of sets and one set is not quite matched. >> It can be measured whether the tube is conducting or not. Made by JJ Electronic. Since the voltage on the secondary is set to 1 volt, the voltage measured on the primary will be the turns ratio. I used a 6L6 which if I remember is a higher power version of the 6V6. 9 non-keyed; keyed it is 148. The original metal version was rated for 19 watts dissipation while the later 6L6GC is usually rated for 30 watts. As the 6AQ5 is a higher power tube than the 6AK6, the power supply in this version is in the more traditional configuration of supplying the output stage plates first, at higher voltage than the pre-amp. The FCC wanted driver plate input power to be included as a full part of power amplifier plate input power. There is no set screw. K = Cathode. This 6V6S can handle higher plate voltage than a standard 6V6 like many of the vintage ones. 2 W Typical Operation AF Power Amplifier, Class A1 (single tube) Plate Voltage 315 V Grid 2 Screen Voltage 225 V Grid 1 Control Voltage* -13 V Peak AF Grid 1 Control Voltage 14 V Zero Signal Plate Current 34 mA Maximum Signal Plate Current 35 mA Zero Signal Grid 2 Screen Current (avg) 2. This would kill many 6V6 tubes (and had in the past). The amount of charge that moves into the plates depends upon the capacitance and the applied voltage according to the formula Q=CV, where Q is the charge in Coulombs, C is the capacitance in Farads, and V is the. Magazine entitled "Look Ma - No High Voltage" It is a milliwatt range vacuum oscillator kit assembled breadboard style using a new old stock 12K5 vacuum tube that uses 12 volts dc on both the filaments and the plate. If you use tubes that require less bias voltage, it's like having extra gain. The Tung-Sol, and RCA rate the GTA the same as a GT or plain 6V6 with plate at 315 V 12 W and screen at 285 V 2 W. To calculate the minimum amount of capacitance needed in the filter section. The MaxiBurn mounts 30 tubes in 6 strings of 5 tubes each. 20 ma is a little cold. While we could increase current by decreasing electrode spacing (denominator term), there are mechanical limits to the tolerance and size that can be realized in vacuum tube construction. Introduction. since each half-coil only has a 50% duty cycle. I had read where it was mentioned Marshall sets them at about 21. Since the voltage on the secondary is set to 1 volt, the voltage measured on the primary will be the turns ratio. From the graph, the red dot is the picked operation point, you can see the grid voltage is at -1V, plate voltage is about 130V, plate. (by modulating the screen and plate voltage), this results in. It was a very simple amp, using one 12AX7, one 6V6 power tube and a 5Y3 rectifier. We burn-in, test, and match all of our Ruby tubes. Please be aware of that using gz34 or diode rectifier will wear you 6v6 power tubes faster than with a 5u4gb due to the higher plate voltage. In these calculations, 5% of the cathode current is assumed to be screen current. Cathode voltage is 26V, so current is (26/470) = 55mA. Plate voltage is measured right at the plate of an operating and idling tube, with respect to ground. 12W or so). : INTRODUCTION Last time I touched vacuum tubes was around 1967 when I was repairing radios and TV. voltage and plate current. 6V6 Pushpull Calss AB Tube Mono Amp. Fwiw my attempt at simplification is that plate voltage doesn't define the sound of a properly designed amp. This seems to be linked to the glowing of the 6v6 tubes. 2 out of 5 by 5. com: 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): Home Audio & Theater. the sound of the mini torri triode strapping is very relaxed with beautiful tones , perhaps not as clean as it was before. In most AB1 push pull amps, the Screen voltage is is very close to the same value as the plate voltage, most tube failure is due to exceeding screen voltage and current ratings. Plate current for each tube can then be calculated from the voltage drop between the OT center tap and plate lead using Ohm's law. Notice that the G1 voltage (Vg. This is really quite low compared to many of the Deluxe Reverbs I've worked on. 4 out of 5 stars 10 $16. They drop the plate voltage by 100 volts. SYLVANIA 6V6GTY Brown Base black plates Matched Pairs $55. The transmitting tubes TT21 and TT22 have almost identical transfer characteristics to KT88 but a different pinout, and by virtue of their anode being connected to the top cap have a higher plate voltage rating (1. Just 1 volt difference in the bias voltage can make a difference of 10 or even more ma, of anode current. I'm working on Stromberg -Carlson model 430. Sounds great. plate voltage. B+ voltages are 384-349-263. The design was based on the 6L6GC tube with higher power ratings, and featured a coke bottle shaped envelope like the European KT66 tubes. The JJ 6V6S (which doesn't sound like a traditional 6V6 to me, more like a 6L6) can handle 450V plate voltage. The ratings 7581 are roughly the same as the 6L6GC while the 7581A has higher ratings. Grid bias voltage would have to be changed too. For the 6V6 tube, find those that are for triode connection. Rectifier is 5u4g Fender. RF -Transmitter Tube Amplifiers I have built custom amplifiers using a variety of World War II transmitter tubes. The Tung-Sol, and RCA rate the GTA the same as a GT or plain 6V6 with plate at 315 V 12 W and screen at 285 V 2 W. The JJ 6V6S is one of them. It was a very simple amp, using one 12AX7, one 6V6 power tube and a 5Y3 rectifier. 6V6 Pushpull Calss AB Tube Mono Amp. The other secondary windings. the voltage on the plate are now 220V , the regulator are brighter than usual but it seems working. I just found my notes from original build; the 6V6 has 315v on the plate, 18. I play clean at low volume, with no external effects, and the warm, smooth midrange the Brimar's provide is just what my 52 Reissue Telecaster and I were looking for. The JJ 6V6 can even be used in place of a 6L6 in some amplifiers. It took a great deal of experimentation, but the Son of Yeti rocks (and much more). I mean 18 Watts. splawn amplifiers All Splawn amplifiers and cabinets are proudly hand-built in Dallas, NC, USA New Drop B+ Switch Option Lower plate voltage to give the QR more sag & feel. Since the voltage on the secondary is set to 1 volt, the voltage measured on the primary will be the turns ratio. You can measure it directly by placing the red. Call now! 516-314-0357. Real 6v6's(that can take the current)are hard to find these days as JJ"s and others label a small 6L6(5881)as a 6v6v. The Tung-Sol, and RCA rate the GTA the same as a GT or plain 6V6 with plate at 315 V 12 W and screen at 285 V 2 W. The author cames no responsibility for any information provided. If you use tubes that require less bias voltage, it's like having extra gain. This page is primarily concerned with a method of plate-modulating a class-C RF stage without the usual modulation transformer. However, you must take into account the duty cycle factor of the class of operation. And RCA 45 Single Ended Amplifier. 241) Hi, I'd like to know which out of the tubes listed are the best sounding, as I have found a dealer and he has a whole selection. Shunt Voltage Regulator with Zener Diodes This is a simple shunt voltage regulator for the screen grids of SE DC 6V6/6AQ5 finals. Normal function of each tube is indicated by an ‘active’ LED next to the tube socket. 6 divided by the plate voltage for 70% dissipation - if your plates are up around 500V you're gonna be looking for around 39mV - whether your bias has enough juice to get you there is to be seen - I'm willing to bet it's gonna be a close race the grid's gonna be up around. While you're at it, check and/or adjust the bias on your 6V6s. Key Features:. This is borne out in actual use and greatly simplifies the. Through this technique, you can take any voltage and lower it to any level you want. The 6CW5/EL86. NOS 6V6 tubes usually can't handle more than 300 volts on the plates. Use of these parameters shall be entirely at the user's own risk. The plate voltage is fine! However,if you want to try 6V6`s in a Rocker 30, you need to run them into an 8K load! The Rocker 30 has a 4K load which will become an 8K load if you use the 8 ohm jack to run a 16 ohm speaker! This amp also has 2 cathode bias resistors, one 270 ohm and one 330 ohm, wired in parallel. Unlike the 6V6 which showed distinct distortion variations by plate voltage, the 6L6 seems to not exhibit such a dependancy. The figure below is a plot of the static plate. Calculate Plate Dissipation In Cathode Biased Output Stage Based On Voltage And Resistance Readings In these calculations, 5% of the cathode current is assumed to be screen current. Overall this tube has a warm and balanced tone with incredible separation and response. On the common octal tubes, this can be measured with a voltmeter between pins 3 and 8. The pentode consists of an evacuated glass envelope containing five electrodes in this order: a cathode heated by a filament, a control grid, a screen grid, a suppressor grid, and a plate. We used JFETs to replace the two halves of the 12AX7 and the 6V6 power stage. The plate is at 345V relative to ground and the screen is at 290V. Current goes up voltage goes down. GROUP STUDENT PROJECT: SINGLE-ENDED CLASS-A TUBE AMPLIFIER – AUG 10, 2007. Any of the standard octal-base power pentodes common in today's audio amplifiers including 6L6, EL34, 5881 and 6550 can be tested. An OT was used, handling 8 watts and providing impedance matching from a 5k primary to an 8 ohm secondary, which is a common loudspeaker impedance. Plate voltages are similar 6L6 at 360 volts and the 6V6 at 350 volts. (Actual Plate Voltage) Example: Octal - pins 3 and 8 9 pin - pins 7 and 3. The vacuum tube "pulls" on the high voltage like a variable resistor. Perfect for high plate voltage amps like the Fender Deluxe Reverb. 5% Plate load impedance. Valve amps naturally have a high output Impedance and the output Voltage will automatically rise in an attempt to maintain constant power to the speaker. Heater voltages are the same at 6. The pentode was developed from the tetrode tube by the addition of a third grid, the suppressor grid. New user coupon on orders over US. You measure it by placing the red + multimeter probe on the plate pin and the black - probe on the cathode pin. Supplying 120 VAC to one primary yielded 114 VAC on the second transformer's primary, an easy way to make a low voltage transformer. Always measure plate voltage at the tube socket. The tubes I used are all used, these may be weak not sure, I do have some other 6V6's I will try out. power supply it played beautiful for 2 days and quit. Plate voltage DC voltage measured between plate and cathode. 5% Plate load impedance. Use this bias calculator to calculate the current based on the amplifier class type, plate dissipation, tube type and plate voltage. You can daisy chain pedals off of the Iso-Pump, provided that you do not exceed the maximum current capability of the IP-1 at the given voltage. I do have it set for buck/boost now. Limiting the plate voltage limits the total plate dissipation, which in turn limits the output of the tube, which is contradictory to most traditional designs which are trying to maximize output per tube (and that's why it's not as common)so if it doesn't matter to me that my EL34 will only be putting out 5 watts in class A (or if that's. EL34's require only 40 volts or less depending on the plate voltage. It will make your amp sound better over stock and deliver clean and crunch tones. I know that many sources for biasing information just specify plate (or cathode) current settings; telling you to bias your 6L6s at "35 milliamps" is nonsense. Find the graph that plots the plate current against the plate voltage labeled average plate characteristics. I'm thinking of having a 6V6 drive a 6V6 for 10-12 watts of output using a plate voltage of 300-ish. Tung Sol on the other hand has a cap on its maximum plate voltage of 315Vdc. The voltage then comes out of the tube through a interstage capacitor into the 6V6 tube that drives the audio transformer. It takes a lot of negative voltage to show a 'healthy' crossover notch on this amplifier. The voltage and power rating of the 6L6 series were gradually pushed upwards by adding features such as a Micanol base, thicker plates, thicker grid wires, grid cooling fins, and special ultra-black plate coatings. The average beam power output tube, such as the 6V6 requires a load of around 5,000 ohms, and the average speaker voice coil can vary from as low as 1 ohm to 8 ohms or more. The JJ 6V6 can even be used in place of a 6L6 in some amplifiers. 6L6 tubes will draw more heater current and can operate at higher plate voltages. The plate voltage of the 6V6 output tube is stated as 342V DC, giving us a 13V drop across the output transformer primary, which is certainly possible. The original design requires that the plate-tuning capacitor (C4) be insulated from the chassis as the plate voltage is present across the plates. The voltage then comes out of the tube through a interstage capacitor into the 6V6 tube that drives the audio transformer. Used with a basic multimeter (Get Yours Here). For example, if the voltage on the primary measures 25 volts, the turns ratio is 25:1 as illustrated in figure 2 below. But due to the ruggedness and quality, most people got away with it. Free shipping on orders $105 and over. Chances are, yours will, all other things being equal, and assuming your bias is set to the B+ voltage and not just some generic spec that was used for the "average" amp at the factory. Using only a pair of KT88 I have got 25W in triode connection and 35-40W using the ultra linear configuration. Control plate in silver coloured plexi and chassi in black tolex is standard issue. This information is for reference only. The TAD-1 is designed to be used in any single output tube, class A, cathode biased, amplifier with plate voltage below 425 volts such as a CHAMP, PRINCETON, HARVARD, BRONCO, or CLARK lil'bit. Two 6V6 tubes per channel is 1 amp rating and four tubes per channel is 2 amp rating on the 150 volt winding. 45 amp for the 6V6 and. This was remarkable compared to other tubes available at that time, which required higher plate voltages and/or higher driving power for the same output. So, how do we determine which of our output transformers will match that impedance range?. 6V6 (METAL) GE,RCA $10. Is there a way to decrease the plate voltage in an AL-811H without using a variac? My line voltage is around 120v or so and the plate voltage in my amp is right at 1800 - right at the red mark. 6V6 Single-Ended (SE) Ultra Linear (UL) Bias Optimization At fifteen feet it mellows into an acceptable sharpness. The rig offered some rudimentary AM (plate) modulation. experienced any problems with the higher plate voltages and the Electro Harmonix 6V6 tubes. Set up your DMM to measure DC volts, selecting an appropriate voltage range (at least 400 volts DC). If the chart is right, both your Plate voltage and bias setting are too high for this tube. Beam power tetrode with a specially developed cathode coating, careful alignment of the grid, tri-alloy plate material for flawless performance up to 475 volts. Plate current for each tube can then be calculated from the voltage drop between the OT center tap and plate lead using Ohm's law. It appears for RCA and Tung-Sol, the only difference between the GT and GTA is the heater warm up time. The value of the cathode resistor will vary depending upon the type of output tube used, and can range in value of 150 to 600 or so ohms. 1 x Plate current / voltage probe for testing anode current / voltage on most octal power tubes like 6L6 6V6 EL34 KT88 5881 6B4G At the moment all units are equipped with a Fujisoku function switch, also insulated or gold plated banana plugs are optional ( no difference in the price ). 6V6 and 6L6 tubes share the same base. The transmitting tubes TT21 and TT22 have almost identical transfer characteristics to KT88 but a different pinout, and by virtue of their anode being connected to the top cap have a higher plate voltage rating (1. Re: Which 6V6 Tube Is Best? Originally Posted by tweedguy The suffix may indicate glass changes but can also indicate internal operating changesFor example, difference between 6L6G (lower plate voltage max) and 6L6GC (higher plate voltage max)also suffix like GT can correlate slope shoulder glass etc. This 6V6S can handle higher plate voltage than a standard 6V6 like many of the vintage ones. IC = Do Not Use (Internal Connection). I think the wall voltage was right at 120 v AC that day. The plate voltage rating is a little lower than for a 12AU7, but for most applications, it will work quite fine. The schematic shows the output transformers' primary impedance to be 8,500-Ohms(plate-to-plate) (Zoo), so the tube impedance is something LESS than 2,125-Ohms (Zo), assume 2,000-Ohms (Zo'). I'm thinking of having a 6V6 drive a 6V6 for 10-12 watts of output using a plate voltage of 300-ish. The waveform is seen below. What brand/model power tubes are installed? JJ tubes are rated at 500V but most old stock or original characteristics indicate 315-350 volt maximums. Thus in a conventional ultra-linear circuit there is no way the Screen-grid DC voltage can be stable. Plate 7B6, pin 2 132 126 Plate 6V6, pin 3 230 216 Grid 6V6, pin 4 250 242 Section 3 PL. As the output Voltage rises, especially at high power, a tranny without sufficient Inductance at bass frequencies can easily saturate creating intense distortion. The pentode consists of an evacuated glass envelope containing five electrodes in this order: a cathode heated by a filament, a control grid, a screen grid, a suppressor grid, and a plate. Every datasheet I see for the 7062/e180cc has the max plate voltage at 275 volts. These are among the very best 6v6 tubes for the cost. 6V6G used/tested $15. Fwiw my attempt at simplification is that plate voltage doesn't define the sound of a properly designed amp. According to my RCA tube book that's falling apart at the seams, literally. Plate voltage DC voltage measured between plate and cathode. It takes a lot of negative voltage to show a ‘healthy’ crossover notch on this amplifier. If you have not been trained to work with high voltage then have an amp technician adjust the amp's bias. (Actual Plate Voltage) Example: Octal - pins 3 and 8 9 pin - pins 7 and 3. New Duncan Munro Vacuum Tube Models. For instance, 40 mA at 250 volts is 10 watts; the same 40 mA at 500 volts is 20 watts. The Howler Monkey Push Pull 6AQ5 Guitar Amp (C) 2012, G. This means that our equipment really needs three supply voltages: A low voltage for filament power (possibly AC), a positive voltage (B+) in the order of 50-350V for plate power, and a negative voltage (B-) in the order of 6-20V for grid bias. I'm thinking of having a 6V6 drive a 6V6 for 10-12 watts of output using a plate voltage of 300-ish. I'm here to say I've never been happier with a new 6V6GT, nor has any new offering come close to its full dynamic range and overall sweetness. I have tried different loading on the output transformer secondary to improve things, but without any noticable difference. No additional bias/plate voltage combo probe is required as the plate voltage is the same across all power tubes. The all new 6V6EH combines a specially developed cathode coating, careful alignment of the grid, and tri-alloy plate material to create a rugged, wonderful-sounding 6V6 that performs flawlessly up to 475 volts. The amount of charge that moves into the plates depends upon the capacitance and the applied voltage according to the formula Q=CV, where Q is the charge in Coulombs, C is the capacitance in Farads, and V is the. The 632 based amplifier uses the dual sections of each tube in a push pull configuration. The 6V6 is a low-output power tube (12-18 watts) often used in Groove Tubes amplifiers, including the Champ, Deluxe, Dual Professional, Vibro-King, Princeton, Vibrolux and others. Specifically, the 6L6, 807and KT66 families prefer a Screen-grid load of 18. (Actual Plate Voltage) Example: Octal - pins 3 and 8 9 pin - pins 7 and 3. The screen voltage adjustment is housed on the Royalist's rear panel Voltage adjustment Thanks to Coda Music, Tone King - one of America's top boutique amp brands - is now available in the UK, and it coincides quite nicely with founder Mark Bartel's first design aimed at reproducing classic British looks and tones. We all know that if you try it in an amp, as you change the idle current, you will sag the power supply more or less, changing the plate and screen voltage, which will then effect the actual plate current. When the audio waveform drives Pin 5 of the 6V6 more negative, the plate of the 6AG7 goes more positive. of 6SJ7 + 6SL7 tubes or 12SJ7 + 6SL7 tubes. Using only a pair of KT88 I have got 25W in triode connection and 35-40W using the ultra linear configuration. NC = No Internal Connection. The plates of the beam pentodes used in this, and most other amplifiers, are fairly immune to ripple in the plate voltage. splawn amplifiers All Splawn amplifiers and cabinets are proudly hand-built in Dallas, NC, USA New Drop B+ Switch Option Lower plate voltage to give the QR more sag & feel. These are among the very best 6v6 tubes for the cost. Fitted in new bathroom looks great. But, although we can easily measure plate voltage, we need a way to determine how much current a tube is actually drawing. Another had 250V max volts for both plate and screen which is closer to a 6aq5 spec. By simply plugging in a 6146B in place of the original 6146, and raising the screen voltage from 160 volts to 200 volts, (an operation that wasn't usually very difficult) a transmitter that originally had an output of 69 watts would now have an output of 85 watts. If using four 6V6 tubes, double the current capacity of the high voltage 150 volt winding. 6v6 PP Amp Conversion Read more. A, B and C show a 6V6 grid. But leave them alone so you can pop in EL34's if you want. Title: 6V6 6V6G 6V6GT Author: Tung-Sol Subject: JA-FP-2005-11-06 Created Date: 11/6/2005 11:41:14 AM. 4 out of 5 stars 10 $16. Maximum signal power output for the 6V6 is about 5 watts. Find great deals on eBay for tube bias tester and tube bias meter. The 150 volts is rather high with 220uF I would use on the voltage doubler capacitors vs the 22uF shown that does require 150 volts. 025A x 140 ohms = -3. As the plate voltage is about optimal for driving the 6G6 close to its limit, and is pretty easy on the 6K6, I can't see too much advantage to be gained running the 6V6/6AQ5 hungry. But 6V6 at 300V (and 30V cathode-bias) is a very fine amp, and in-line with your simple 330V supply. 12W or so). com: 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): Home Audio & Theater. I also read about typical Champs with bigger PTs running 350v-400v on the 6V6 plate, using a similar 470r cathode resistor. Electro-Harmonix 6V6 EH Vacuum Tube Sweet, singing tone for high plate voltage amps. A note about 6v6 plate and screen voltages: So the north American distributor for JJ electronics (eurotubes. History shows Hafler and Keros successfully patented in the USA a further development of the general concept that had already been patented by. The JJ 6V6S is one of them. It was found that under optimum conditions such circuits could provide extremely high gain -even more than at high voltages- and some engineers exploited this property for DC instrumentation amplifiers. D shows a 6L6 substituted for the 6V6 and tuned for optimum. I use JJ's but have good transformers so it's ok. It was not designed for 6V6' but,I was told I could use ones that can handle the plate voltage. Title: 6BQ5 8BQ5 Author: General Electric Subject: JA-FP-2000-11-19 Created Date: 11/19/2000 11:18:15 PM. Free shipping on orders $105 and over. It also requires somewhat greater plate voltage (but less power wasted in the screens) to produce the same power and occupies more space. I'm looking to build a 6V6 SE guitar amp and will be grateful for your advice. The 6V6s should see about 305VDC at the plates and SGs, so their B+ should be 310-315VDC, depending on the DCR of the OPT primary. The first thing to notice here is that the distortion does not seem to vary by plate voltage. 8 % Maximum signal power output 55 W Svetlana SV6L6GC High Performance Audio Beam Power Tetrode. This is not surprising since they all have very similar construction. plate voltage is 350V. Plate voltage x current = plate dissipation (watts) Example: 450 volts plate voltage x 40 mA (meter reading) = 18 watts plate dissipation; this would be considered safe for an EL34 but dangerous for a 6V6. plate dissipation, it can be done by re-biasing, but you need to know what you are doing. In the 1950s, professional audio designers began to make use of the 6V6 for high-fidelity amplifiers; this ultimately resulted in a “premium” version of the tube, designated the 7408. Tadaatsu Atarashi. I usually keep bias around 19 or 20. Plate voltage DC voltage measured between plate and cathode. Extremely hot for a 6V6 tube, but apparently intentional on Fender's part. 20 ma is a little cold. A pair of 6V6 can do 14 Watts with 285V cathode-bias, 25+ Watts with 360V and fix-bias. I'm thinking of having a 6V6 drive a 6V6 for 10-12 watts of output using a plate voltage of 300-ish. Fitted in new bathroom looks great. In these calculations, 5% of the cathode current is assumed to be screen current. The NOS GE 6V6 and the current-production EH 6V6 are essentially the same in power draw. with a 6V6 Class A modulator. The plate voltage with them I measured is 435V ! The question now is, can I put those NOS tubes in that Deluxe Reverb? Will they blow? I read somewhere that for some old NOS 6V6 tube the max. V6 12at7 = Phase inverter. This page is primarily concerned with a method of plate-modulating a class-C RF stage without the usual modulation transformer. Plate voltage x current = plate dissipation (watts) Example: 450 volts plate voltage x 40 mA (meter reading) = 18 watts plate dissipation; this would be considered safe for an EL34 but dangerous for a 6V6. The transmitting tubes TT21 and TT22 have almost identical transfer characteristics to KT88 but a different pinout, and by virtue of their anode being connected to the top cap have a higher plate voltage rating (1. (Actual Plate Voltage) Example: Octal - pins 3 and 8 9 pin - pins 7 and 3. Call now! 516-314-0357. A voltage change on the control grid will cause a corresponding change in the plate current, so basically, the tube is a voltage amplifier, but the input voltage signal is changed to a current signal. Power output, of course, will be a function of plate voltage. I tested 10 different sets of 6V6s in a Fender Tweed Deluxe and Fender Blackface Deluxe Reverb. The tubes I used are all used, these may be weak not sure, I do have some other 6V6's I will try out. The JJ 6V6 can even be used in place of a 6L6 in some amplifiers. CALCULATE PLATE DISSIPATION Based on Plate Voltage and Cathode Current Readings. The 6AQ5 is a lower power 6V6 in a 7 pin package used originally in car radios, and the 6L6 is an upgraded 6V6 with higher voltage and higher current. 75v on the cathode, 38. I'm using a 16-ohm speaker on the 8-ohm tap as per advice on the interwebs. The 6K6 is almost identical to a 6V6 but requires a lower plate voltage and a different resistor value for cathode biasing. 5V4s are indirectly heated and take longer to conduct which means B+ takes a few more seconds to get going. Again, this is likely due to the excessive voltage that I’m running as well as having the bias a bit hot. about 9W, my question is, if you were to run those tubes at or around 12W, how much would it shorten the life of the tube by? would it halve it. The designs I have seen list the HT at 320~340V. You should always avoid having more than 430 volts across a 6V6 (plate voltage minus cathode voltage). Restoration download hi res. Clip the black test lead to a secure chassis ground point. Preamp Tubes are Cathode Biased, in which the tube biases itself. 6V6 Single-Ended (SE) Ultra Linear (UL) Bias Optimization At fifteen feet it mellows into an acceptable sharpness. 9 watts) Divide your desired wattage by the plate voltage that you wrote down from step 2. The day I recorded the numbers on the 5U4 versus the 5R4 rectifiers, the voltage at the wall was 122 AC. I'm thinking of having a 6V6 drive a 6V6 for 10-12 watts of output using a plate voltage of 300-ish. Re: Which 6V6 Tube Is Best? Originally Posted by tweedguy The suffix may indicate glass changes but can also indicate internal operating changesFor example, difference between 6L6G (lower plate voltage max) and 6L6GC (higher plate voltage max)also suffix like GT can correlate slope shoulder glass etc. We know RCA first released the 6L6 as 400V, then quickly re-rated for 360V. There was a PA-497-6 as well. The modern tubes will handle higher plate voltage, the older ones will not. The original design requires that the plate-tuning capacitor (C4) be insulated from the chassis as the plate voltage is present across the plates. I also read about typical Champs with bigger PTs running 350v-400v on the 6V6 plate, using a similar 470r cathode resistor. High I know but not uncommon in these amps I think. The 17" reverb tank provides a deep echoey sound. I remember this old radio HIFI that was stripped from a console back in the early 60s There was a 12 inch speaker and a smaller speaker I think mid. Rocker 15 - Orange Amps Forum Read more. I usually keep bias around 19 or 20. Tube action translates the DC voltage into tube current draw, which is how the operating point is expressed. To calculate the minimum amount of capacitance needed in the filter section. Here, however, the 6V6's are driven by 6AU6 pentodes operating at a very small plate current with large plate resistors, and a grid bias of -1. I gave a full review of the Ruby tubes in an earlier blog post. This 6V6S can handle higher plate voltage than a standard 6V6 like many of the vintage ones. This new driver stage can be used without changes in the PP2010 to get 50W. V5 12ax7 = Vibrato. The 40mv is for both tubes. In the 1950s, professional audio designers began to make use of the 6V6 for high-fidelity amplifiers; this ultimately resulted in a “premium” version of the tube, designated the 7408. JBH 6j4 ( EF94 ) 6p6p ( 6v6 ) Tube Pre-amplifier HIFI EXQUIS best sound high density bass preamp finished product - This tube pre-amp use some very welknow tubes:Chinese 6j4. New Plate Current Matched Pair of JJ 6V6 (6V6GT) Vacuum Tubes. Since the voltage (relative to "ground") on the cathode is lower, it is safer to measure than is plate current or voltage. ) will change optimum plate load impedance. 6V6 Pushpull Calss AB Tube Mono Amp. pentode meg. I got about 282V at the plates, and 12V at the cathodes. The JJ 6V6S (which doesn't sound like a traditional 6V6 to me, more like a 6L6) can handle 450V plate voltage. Please do not copy info contained here without a link back to this page !. Free shipping on orders $105 and over. This is not surprising since they all have very similar construction. The lower portion of the inside is wider and would fit about a 7mm shaft, which would need to extend out about 15 mm from the face plate. Plate voltage definition is - the constant component of the potential difference between plate and cathode in an electron tube. The TAD-1 is designed to be used in any single output tube, class A, cathode biased, amplifier with plate voltage below 425 volts such as a CHAMP, PRINCETON, HARVARD, BRONCO, or CLARK lil'bit.