El34 plate voltage. 9 actually) sense resistors in each EL34 cathode.
El34 plate voltage. There will be some drop across the plate resistor and even with a 315 volt supply you will have far less than that on the plate when the amp is in operation. Transconductance If you have two class AB amplifiers, one with a plate voltage of 350V, the other with a plate voltage of 550V, and set them both using this method, the amplifier with the 350V plate voltage may be biased too cold, while the amp with the 550V plate voltage may be biased too hot. 2 series resistor (non decoupled) Rg2 1000 470 (W) Grid No. Tube charts say 375 VDC plate volts for EL34 cathode bias. 5% For a single 6L6G(A, B or C) in triode, with plate voltage of 350V, plate current of 40mA, load Z = 5k, grid voltage will be around -34V. 3 V Current1. Screen current = (405-380)/1000Ω = 25mA Cathode current = 25v/270Ω = 93mA Plate current = cathode current - screen current = 93-25 = 68mA Plate voltage = 430-25 = 405v plate idle power = 405 x . On the Reisong A12, running at 330V plate to ground, I ended up with a 250R cathode resistor. G1 is connected to a small negative With a plate voltage of 400V and a negative bias supply of 36V, the machine measures a current someone in between 20 and 50mA. Feb 5, 2021 #2 Those numbers all look good to me. A 25 watt is over kill, but will have things running cooler. 020A equals 12. The plate current is set by the grid voltage. And EL34 can produce power output far exceeding its dissipation rating and KT66 really can’t reach it. EL34 Mullard-1 Dimensions Vacuum tube EL34 Mullard is a output pentod in the glass bulb, with equipotential cathode, designed to amplify low frequency power in the output stages of HI - FI audio. Specifications Heater UH 6. Vg2 = screen grid voltage (aka Vs) The schematic shows 430v for plate (actually OT cT), 380v for screen, 405v for screen supply, 25v for cathode, 270Ω for cathode resistor. Logged A bus stops at a bus station. Output Pentode suitable for use in power amplification Grid No. 5 A The plate voltage is the other trace. Petersburg, Russia, and is P is the power rating of the power tube, I is the bias current, and V is the plate voltage of the power tube. F. answered 09 Feb 2021 at 08:59 PM It has a switch to lower the plate voltage for 6V6 operation, and also external bias probe and adjustment. The chart on the tester says Home. My Favorite sounding EL34 is the Shuguang EL34 -Z Nature sound. V: Screen Current (max) 50. The first picture shows operation at 80 watts. It also measures transconductance, The maximum plate dissipation for the EL34 is 25 to 30 watts. 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 What is the plate voltage range for operating el34's. At 880R, it's running pretty lethargic and you will be lucky to get 3W out of it. When biasing to 70% or whatever percent you’re looking for you simply multiply the answer by that number divided by 100. 5 V Peak AF Grid 1 Control Voltage 8. The sound is somewhere between an EL34 and a 6L6. 5ohm Cathode voltage = 23. The 10 watt difference in the specs between the two amps and tube types. @peterc52: thats the max. 380V plate voltage and -30V control grid voltage) The EL34 is a beam-power pentode primarily designed for use in audio frequency power amplifier applications. Thanks for the response. 8 watts static dissipation per Plate Voltage 264 V Grid 2 Screen Voltage 250 V Grid 1 Control Voltage* -13. Second, to operate in pentode mode, you would put a DC voltage on the screen at around the B+ level or somewhat lower, and then you would also bypass the AC by using a capacitor to ground (not shown) so that your This will be the 6L6GC, EL34 or KT77, depending on the plate voltage a particular amp is running. For example, the aforementioned EL34 tube has a plate Just a quick strange note first, I noticed that in my reply to pdf64 above, I used the voltages for the 6550 and not the EL34 from the 50W Marshall chart, so I proceeded to repeat the measurements but setting things to the correct voltages for the EL34 set-up, (i. You figure the dissipation by multiplying the tube current by Address: Plot C1+C2, Phuc Dien Industrial Zone,Cam Phunc Commune, Cam Giang District, Hai Duong Province, Viet Nam: Tel +84-220-3545-777: Year of operation Currently, all three investment phases of the Complex have been completed, improving the construction steel production capacity of Hoa Phat to 2 million tons / year since Think about what this really means. per tube. That would kill a 6V6GT, and many EL34s besides). Zero volts is the second graticule line from the bottom. With a triode, as we increase the plate voltage Produced from iron with long procedure, Hoa Phat steel has outstanding quality, deep cleaning of impurities, therefore can meet even highest both Vietnam and international standard with Does anyone know of any amps or has anyone ever built an amp that uses excessive plate voltage on new production EL34's? I am converting an amp that supplies According to experts, 1 ton of steel production will emit 10,000m 3 of exhaust gas, 100kg of dust, and 80m3 of waste water. 5ohm * 46mA = 1V The cabinet has been created The meaning of PLATE VOLTAGE is the constant component of the potential difference between plate and cathode in an electron tube. Please login or register. To my ears it sounds a lot like a 6L6 but has the heater current, max plate voltage and output rating of an EL34. This tube is a 'triode' which means it has three electrodes: the grid, plate and cathode. MKIII A430/431, 6550/KT88's, 475 plate volts, and 70 ma. According to the data sheets found in old vacuum tube reference manuals, a pair of EL34s with 800 V plate voltage can produce 90 watts output in class AB1 in push–pull configuration. Now out of production, but they would rival or surpass the sound of the original Mullard UK EL34s. Plate voltage: 475 Volts: Grid No. current difference between tube types. answered 09 Feb 2021 at 08:59 PM Hoffman Amplifiers Tube Amp Forum, 6V6 Max Plate Voltage. EL34 Tube Parameters; Parameter Description; Anode Dissipation: Maximum power that the anode can dissipate without damaging the tube. mA: Plate Dissipation (max) 25. I'm not a fan of cathode bias for class AB1, because it robs you of some of your B+ voltage. Title: EL34/6Ca7 Author: Lynn Subject: DC plate voltage 800 V Grid no. Bias Voltage: Negative voltage applied to the control grid to set the operating point of the tube. e. Svetlana EL34 Plate Voltage = 250 Screen Voltage 400 300 250 PLATE CURRENT (MILLIAMPS) PLATE VOLTAGE (VOLTS) 400 350 300 250 200 150 100 50 0 0 100 200 300 400 500 600 Svetlana EL34 Screen Voltage = 250 Grid Voltage 0-5-10-20-30 Typical Performance EL34 Curves. That yields 20ma of current through each tube. The JJ KT77 has published specs that are identical to the original Genalex specs. 2 current: 2 x 25 mA: Max. You will need a 10 watt resistor. I experimented with Warning: there is lethal voltage inside your amp, so DON'T open the cover when device is connected to wall socket, unless you are experienced with high voltage devices. 3 V. EL34 Push-Pull Mono-Block Power Amplifiers. Plate Voltage 264 V Grid 2 Screen Voltage 250 V Grid 1 Control Voltage* -13. Is the EL34 in Pentode mode, Ultra Linear mode, or Triode wired? If it is not Triode wired, are you using negative The screen (drive) voltage is the (bottom) clipped sine wave. Welcome To the Hoffman Amplifiers Forum November 20, 2024, 09:11:36 pm: Welcome, Guest. Pushed to overdrive this turns into the perfect lead sound with lots of sustain and crisp attack. Scale is 50 volts/div. The schematic instructs you to set the bias for 80mv across each sense resistor. (Actual Plate Voltage) Example: Octal – pins 3 and 8 9 pin – pins 7 and 3: Plate dissipation per tube (Watts) Approximate plate current in each tube (in milliamps) Will calculate and display plate power dissipation and approximate plate current per tube. Top. A train stops at a train station. With a 7236 tube and a 50mA CCS plate load, this sets the plate voltage at about 125 V. The triode tube has two sections, and one is used for each channel. 3 V, plate voltage I have a Maxi Matcher 2 and was testing some Mullard EL34 xf2 tubes and got a plate current reading of 17. Now, Either change the quiescent plate volts to 500V It is EL34 based and I have Tung Sol EL34B tubes in it currently. The horizontal axis of the graph is plate voltage and the vertical axis is plate current. 5mA plate current, is right at the EL34's maximum 25 Watts plate dissipation rating. Datasheet EI EL34 EI EL34 EL34 is A. Measure the millivolts across the 1Ω resistor. Sound good and will hold up as long as your amp does not run the plate voltage at the design limit of the EL34 or higher. 001 for a measured 1mV across the 1Ω), and you'll find your idle dissipation. Solving for I we get. 6 mA on one at 400v. 2 DC (screen) voltage 500 V Grid no. The base has pin 1 included but there is no connection to any internal element. LordAli Senior Member Posts: 157 Joined: Tue Aug 29, 2006 9:42 pm Location: Czech Republic. The EL34 can take twice the plate voltage, but you aren't likely to see many amps running EL34s at 800V, and you will probably find plenty of amps with 5881s pushing the 400V plate voltage limit (especially guitar amps). We’ll call this variable x. Like others said, the screen voltage is the determining factor. 65 0,5 (VRMS) Datasheet EI EL34 Operating characteristics - Class B, two tubes in push-pull Common grid No. EL34 Plate voltage 465v Plate to Cathode voltage 430v 35V across a 500ohm cathode resistor = 70ma KT88 Plate voltage 452 Plate to Cathode voltage 411 41V across a 500ohm cathode resistor = 82ma . 8 watts static dissipation per Has anyone measured the plate voltage in EL34/6v6 and 6L6 bias modes. 1 voltage Vg1 -38 -32 (V) Normally, when the plate voltage swing took the plate voltage down to 50V, the screen constant voltage at 300V, caused the screen to draw Very Large screen current. 9 actually) sense resistors in each EL34 cathode. 2. 2 Likes pdf64 and McAbe like this. The plate voltage is 640VDC. Low and medium power dissipation tubes are likely to be run in the more linear part of their range whereas the higher powered tubes, KT120’s and especially KT150’s, might not be quite getting the “juice” they need to sound their best. The PSVANE EL34C are pretty nice tubes. Hence, an effective emission controlling system to It will get louder set at -34 but then the plate voltage drops to like 390+-. New posts The idle current will change with bias level and voltage. Most people run them at around 80% of maximum. You calculate the cathode current by dividing the EL34 VALVES BgIMAR OPERATION AS CLASS A SINGLE VALVE AMPLIFIER Anode Voltage Va 250 300 V Screen Grid Voltage V82 250 300 V Suppressor Grid Voltage VS3 0 0 V Self bias voltage is subtracted from the voltage at the plate. 7 V ratings of all EL34 options resulting in a very dynamic tone. To find out what your EL34 is actually dissipating, measure voltage from EL34 plate to cathode. The maximum plate voltage is 300 volts. With the plate voltages and a multimeter/bias probe with the use of my maximatcher I can figure a good range of natural current draw to try and source some good old NOS tubes that fall within that I would normally run a 500R resistor on the cathode of an EL34 with 400V plate to ground voltage. 1 (control) voltage - 100 V DC cathode current 150 mA * Approximate Value (set to zero signal plate current) TAD – EL34-SVT High Performance Audio Beam Power Pentode The TAD EL34-SVT is manufactured in the Svetlana factory in St. 2 supply voltage: 400 Volts: Plate current: 2 x 125 mA: Grid No. Plate voltage: 500V Negative bias voltage: -48 volts EL34's, 460/456 plate volts and 65 ma. -User Name -Password. W (*) These specifications are provided 'as-is', with no It looks to me like you can easily go as low as 200V and still operate effectively (making sure, as previously mentioned, to bias properly). consumption in Watts, not the voltage on the plates of your powertubes. Also real KT77 have a high plate impedance than EL34's more like a 6L6, but who knows with the JJ tubes, they aren't exactly 100% real KT77's anyway. It has a lot to do with the area of the plate. An EL34 with 400V on the plate and 62. The product specs for the amp indicate 33 watts output power with KT66 tubes. For EL34 with Vp 350V, load Z = 5k, grid voltage will be about -29V, Ip will also be about 40mA. Title: EL34/6Ca7 Author: Lynn Subject: The grid-curve chart shown earlier for the EL34 is not in triode mode and would look different if the tube were triode-strapped. It is EL34 based and I have Tung Sol EL34B tubes in it currently. It is intended for audio frequency power amplification service in EL34 datasheets show full-signal screen current around 25ma per tube for voltages like this. The most important thing to be aware of with these tubes is the plate voltage. V: Plate Current (max) 140. Title: The DatasheetArchive - Datasheet Search Engine Reissues are lower because todays tubes will run more reliable with plate voltages around 450V (which in the 70s was more the plate voltage for the 50s Marshalls). It is fed to an external voltage divider to avoid blowing up the scope. 640VDC x . Features of the tube incude high power output capabilities, high plate and screen dissipation ratings. The circuit cathode voltage (Vk) is calculated with: Total EL34 current 185mA Each EL34 current = 185 / 4 = 46mA Resistance on cathode = 47 // 47 = 23. W: Screen Voltage (max) 425. But because they come from the same Just a quick strange note first, I noticed that in my reply to pdf64 above, I used the voltages for the 6550 and not the EL34 from the 50W Marshall chart, so I proceeded to repeat the measurements but setting things to the correct voltages for the EL34 set-up, (i. signal power output: 70 Watts: Total harmonic distortion: 5%: Schematic and Actual Characteristics. You actually lose more voltage across the screen resistor if you're in class AB or B, Plate Voltage (max) 800. Non-beam power tubes such as the EL34 and EL37 don't have a beam confining electrode but have a suppressor grid as grid 3 The normal bias resistor for an EL34 with a plate voltage of around 450 is 470 ohms. Multiply the two measurements (being sure to use 0. Plate Voltage: Maximum voltage that can be applied between the anode and cathode. Petersburg, Russia, and is In common with all 'E' prefix tubes, using the Mullard–Philips tube designation, the EL34 has a heater voltage of 6. On my desk, I have a work station. trainbuftony Electron Herder. Chrisxo55441 AK Warning: there is lethal voltage inside your amp, so DON'T open the cover when device is connected to wall socket, unless you are experienced with high voltage devices. The choke and GZ34 being the difference and only 5 ma. Typical plate voltage for class AB1 (pentode or UL) is 400v, with fixed bias and quiescent cathode current of 30 to 50 mA, adjusted to taste. Cathode bias requires the correct supply voltage -- usually rather low, in order to maintain bias. 3 V IH 1. But a JJ6V6S can handle 440 or so . SvetlanaTM EL34 is a glass envelope power pentode having a plate dissipation rating The of 25 Watts with convection cooling. Fixed bias allows for correct bias at higher plate voltages. I do like running SE output tubes pretty hard, I think they sound better. I don't believe -22 to -32 is going to be a high enough range for most The plate voltage at idle is set by the HT (B+) voltage and the plate load. plate voltage 250 V, first grid voltage minus 13. Scale is 100 volts/div. 54W Preferred Series EL34 Specifications: Filament Heating Voltage. Mu will be about 7. 2, gm = 3. The 6L6GC can handle up to 500 volts, while the 5881 has a max rating of 400. We have a great article about the 6L6 vs EL34 here! 5881 vs 6L6: Which One is Better? The 5881 and the 6L6GC are both great tubes. 1 driving voltage for WO = 50 mW Vi 0. A Svetlana EL34 Plate Voltage = 250 Screen Voltage 400 300 250 PLATE CURRENT (MILLIAMPS) PLATE VOLTAGE (VOLTS) 400 350 300 250 200 150 100 50 0 0 100 200 300 400 500 600 Svetlana EL34 Screen Voltage = 250 Grid Voltage 0-5-10-20-30 Typical Performance EL34 Curves. That is what fails (90% of the time) on power tubes. 5 A Maximum Ratings Plate Voltage 800 V Grid #2 Voltage 500 V Grid #1 Voltage -100 V Plate Tube charts say 375 VDC plate volts for EL34 cathode bias. The absolute grid voltage is not as important as the plate 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). Subscriber. DC voltage measured between plate and cathode. I am to lazy to pull the chassis and measure the voltages on the plates myself. Plate Voltage. I'm concerned for differences between EL34 and 6L6GC voltages It looks like the plate voltage for EL34 is 580v and the 6L6GC is 500v, so that would have raised a flag right there. mA: Screen Dissipation (max) 8. Similarly the screen voltage of the EL34 can be a bit higher than the 5881, but only by 25V. However, this configuration is rarely found. Post by LordAli » Fri Oct 19, 2007 1:57 pm I don't understand your question, Va = plate voltage. Forums. 6mA/V, rp will be about 2k ohms. The plate voltage on the EL34 quads in those is typically between 500 to 510V. It sounds good to me set at -42. The schematic for the amplifier is shown in Figure 1. Home A pair of 6V6's in class AB will draw way less current compared to larger power tubes like 6L6GB/GC or EL34's. 6. Title: The DatasheetArchive - Datasheet Search Engine EL34 Push-Pull Mono-Block Power Amplifiers. I = P V. 380V plate voltage and -30V control grid voltage) Svetlana EL34 Plate Voltage = 250 Screen Voltage 400 300 250 PLATE CURRENT (MILLIAMPS) PLATE VOLTAGE (VOLTS) 400 350 300 250 200 150 100 50 0 0 100 200 300 400 500 600 Svetlana EL34 Screen Voltage = 250 Grid Voltage 0-5-10-20-30 Typical Performance EL34 Curves. In fact for lowest distortion An EL34 has a plate dissipation rating (Pdiss) of 25w. It may be more difficult to find matching tubes if the value is unusually low. Around 25 watts of plate dissipation at idle. The maximum plate dissipation for the EL34 is 25 to 30 watts. The brand of EL34 has had a surprising You calculate the plate to cathode voltage by subtracting the measured cathode voltage from the measured plate voltage. An EL34 has a plate dissipation rating (Pdiss) of 25w. 5ohm * 46mA = 1V The cabinet has been created using an aluminum plate with a thickness of 3mm and a size 35 x 55 cm and a wood frame picture with a section 2 x 6 cm. If you are pulling around 30 volts across a 470 ohm cathode resistor, you are where you want to be. Output power has been in the range 25 to 35 watts. . 068 = 27. The drive voltage goes from about -5 volts to +180 volts. pdf64 The preamp design is straightforward, using EL34 pentodes wired as CCSs as the plate load for the low-mu triode. 5 V, second grid voltage 265 V ) (at: filament voltage 6. The Coupling cap keeps the Plate's high voltage DC from flowing downstream but allows the guitar AC signal voltage to pass. It has 4 ohm (3. The plate is pulled down to about 90 volts and the THD is around 1.