6v6 bias current amp. 7 - (Plate Current / 1000) x 0.

6v6 bias current amp 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. When more current flows, the tube gets hotter, and the grid current goes up even more and you might get thermal runaway. In the introduction I stated "This lack of bias and operation data is the problem which I endeavor to address". 05V. 1 offer from $1699 $ 16 99. I’ve done this with NOS tubes and the JJ 6V6 (an The cathode of the second cap is grounded while the cathode of first cap and the bridge are leaft floating. 52 kB, 1078x600 - One of the things I'd like to be able to do is use 6V6s or 6L6s in it. The other of operating conditions need to be addressed for best performance. 2. So you might have to use the volume controls of a 6V6 amp, Buy Nobsound 8-Pin Dual Bias Current Probes Tester+Dual Large Ampere Meter for EL34,KT88,6L6,6V6,5881,6550,KT66,KT100,KT120 Tubes at Aliexpress for . You may like the sound in that configuration. Setup is a LL1660/18mA used as a plate choke with 0. Class A is reserved for very low power guitar amps (i. The 6V6 transconductance is about 3700 uMhos. Bias refers to the high-frequency alternating current applied to a tape recorder to minimize distortion. Customer ” Joe” puts his four brand new matched Tung Sol 6L6GC-STR into his amp and he checks the bias on each of the valves. Headroom for Having bias test points will let me replace the 6V6 power tubes myself using just a voltmeter or which means that Power (watts) = Volts * Current Draw (amperes). Banana Jack Plug ,same as your multi-meter probe; Tube socket cable lengh: 23cmCopper with excellent conductivity; Ceramic socket and gold pinsDouk Audio is committed to provide highest level of customer My current amp bias circuit only lets me get to about 12ma of plate current, need to get to about 28ma at 420vdc, hence the question. 9% still a bit hgih Say you set the bias at 22ma and I currently use a great little 6V6 PP integrated amp using the op275 J-fet opamp to drive the 6V6s in class AB with about 20v bias @ 25ma idle current from an LM317 CCS. diyAudio Community diyAudio Store. The current draw (the unknown variable we need for setting the bias) can be Since the amp uses two 6V6 tubes in class AB (push 0. I use 70% of max power dissipation method for the tube by measuring current at the cathode. The higher idle current of the hotter tube increases the cathode voltage and makes the colder tube run even colder. 025 14X=10. 25 X=80%. After performing this investigation, I now have a complete set of data on how to bias and operate the 6V6 in the SU UL configuration (at least at one load resistance) Douk Audio 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) 4. Cathode biased output stages don't need the 1Ω measurement resistors, that trick only applies to fixed grid bias that would normally tie the 6V6 cathodes directly to ground. In most common As long as you know (or can test) the plate voltage in your amp, and have a way to measure the idle current, you can determine where to bias it, using our calculator. Likewise although you could measure or calculate bias current, and that is handy to check one 6V6 against the other, Rob's "Tube Dissipation Using Cathode Resistor Voltage Drop" method is really quick and easy and accurate; and although it averages the two Between the bias system in your amp and the natural idle current of the tubes you use, you have the ability to tailor your sound. The cheapest solution. I tested it at idle, max clean (just before clipping) and then just flat out hammered it with a 1V input signal. Individual self bias resistors and bypass caps, one RC per each tube. Some smaller amps with 6V6 power tubes Still, set the mA current as rmconner80 said for an example plate voltage of 425vuse your Weber Bias Rite. using a 360R cathode resistor unbypassed. These probes are $25. Why is my plate current so high in this circuit using 6V6? 2019-04-12 - Single Ended Schematic - Power Amp 6V6. At that time there were two important aspects to this build. e. Arrow points to the insertion index notch. 99/ea. Amazon. Therefore, these tubes are "usable" in his single ended amp. It takes a Chicago BO-6 output with a tertiary winding for cathode FB. 05 V more bias means 3. Find more , and products. He sets the first valve up for See the thread "6V6 Behavior W/Fixed Bias (SE Amp)", post 80 to start with. General discussion area for tube amps. With the current setting on the bias pot, one tube measures 35mA while the other measures 19mA. I was concerned because after I repaired the amp, the 6v6 was still running Without seeing the schematic of your current amp, I am assuming from what you’ve said that this is a major upgrade. 025 14X=11. Financial Bias: In finance, The 6V6 Lacewood amp was designed and built in the first half of 2011. Please login or register. 047uF values to anticipate this amp's transformation: This is the current circuit now: Douk Audio 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) 4. I have decided to build a guitar amp using the trannies. 6V6 bias under 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) : This device made tube bias of the 6V6 tubes a breeze. Im looking for an easy to build, great sounding 6v6 amp since I already have the tubes in hand. So, with LEDs in the cathodes (a kind of fixed bias), 1. Click any Calculate button to see the recommended tube bias currents in milliamps. The tester works for all popular octal-base output tubes (6V6, 6L6, EL34, KT66, KT77, KT88, 6550, and more). The voltmeter only method requires a few more simple math steps to get you there. Unless you take the plate voltage into consideration, a current specification is 6V6: 12 watts MAX: 6L6GC (and variants, like the 7581A) 23 watts MAX Hello everyone, I've been working on some simple single ended guitar amp designs over the past few months and I really want to try running a 6V6 and an EL84 in parallel for the power amp section! I've drawn a rough schematic and attached it to the post, so can someone take a look real quick 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) Used it to check a Fender 5e3 pair of 6v6 bias current. 0mA @ I've been tinkering with an amp build of mine and found the screen grids appeared to be running a bit hot. Particularly the different versions of the Champ using one 6v6 (or two). Select your If I ever design and build a 6V6 push pull amplifier, it will have the following: 1. under 5W) and for higher fidelity audio amps because a 6V6 valve running in class A is lower distortion than a pair or quad running in push-pull. My bias circuit has one 15 k resistor right after the diode and another 27K resistor going to leg of the 25K bias pot. 625 X=75. Normal / None / Heavy selectable feedback. your 250V anode voltage and enough bias to play with. Plate is pin 3 and Cathode is pin 8. 99 $ 16 . Nobsound (Douk Audio) (59360) 99. If you have a bias probe, it is much simpler, as the bias probe is already reading the plate voltage in relation to the cathode, so all you need to do is multiply the plate voltage reading by the current reading to figure power dissipation. If I can get around 4 watts from a smaller amp I think I'd be happy with it. In fact, that covers 90% of the amps out there. Skip to main content. Since 2006 we have offered a single octal bias probe for use with a Multimeter. Bias Current/Voltages 24. Cheers, 45 P. Do I need to worry about speaker impedance or anything if I switch to 6V6's? I'm about to bias my amp and have some questions regarding the differences between 'recommended' values and those found in Fender schematics. 14 being the 100% plate dissipation number for a 6V6. ac or dc mounting pos bottom view intermediate cathode bias operation vertical deflection heater voltage 515 1200 250 55 105 2. Delivering to Balzac T4B 2T3 Update location 12. The bias current Current production 7591s are intolerant of taking liberties with the grid to ground resistance limit and the high plate resistance 12AX7 triode must work into a The self biased schematic with the 392Ω bias resistor will give you about 4. Hoffman Amplifiers Tube Amp Forum, Clarification on Bias Settings for JJ 6v6. I'm about to retube my only 6V6 based amp. I will reuse the tubes (including the 2 5y3 tubes) if possible. current settings; telling you to bias your 6L6s at "35 milliamps" is nonsense. Member. Currently listening to the EL84 in triode which is sounding much better than I expected. a bit high. Otherwise your bias will be too low and the amp will overload easily. So now that I've gone through all this data it's time to decide if I've met my goal. This is an online calculator designed to determine the bias of a tube amp in amperes or milliamperes (mA or A). List of Amp Mods. what was done to the amp, and what the bias/current draw/plate dissipation is when the amp is picked up. Is there anything else I need to worry about? It will be built as a 6L6 amp, so the speakers/trannies, etc. Is it possible that biasing in Fender Champs was not ideal with respect to biasing a 6V6 for Class A operation as Without getting too technical, a 6V6 in ‘Class A’ would be a single 6V6 valve (I. 0mA @ -27. It will have a range of current that is not consistent from tube to tube (just like battery bias). An EL34 can dissipate more power than a 6V6, is everyone using the same bias for an EL34 as a 6V6? And AFAIK even with a 15W amp the maximum undistorted output volume will only be around 1/2 in comparison with the undistorted output volume of a 150W amp anyway. 2V the MOSFET shuts down. 3-Way Negative Feedback Switch My favorite tube amp mod. Read more. I got a pair of PCBs off eBay that claim to be a "Dynaco 6V6 P-P" circuit and I'm trying to understand how it works, and hopefully build an amp around it. , will be chosen to handle the 6l6's. Conclusion. The current will reduce as the tube ages. If the votlage were 425 14X/425=. I don’t have your sophisticated measuring equipment so I don’t know if my audio quality compares to what you describe so for fun this week I will try to build your VER2 amp w/18. 3% positive; Seller's other items Seller's other items; Contact seller; US $19. 5K grid stoppers, and bumped the PI coupling caps up to more common . 1. 1vdc. Given a 5 WPC SE UL 6V6 amp, So id the bias current is to be set to 35mA you should measure 35mV on your meter. 6V6 ~ 12 watts max dissipation Plate voltage: assuming 350V, but you have to measure it in each amp Max current draw: 12w / 350V = 34 mA 70% of max dissipation: 70% x 34 mA = 24 mA Using EL34s I can bias the amp fine. Another solution could be 7x1. The 1st 2 sound very similar. 0 out of 5 stars 32 ratings CT1-P is a bias current probe tester for testing PLATE current of vacuum tubesSuitable for tube model EL34,KT88,6L6,6V6,5881,6550,KT66,KT100,KT120,7027 etc. Then plate dissipation Pa (including screen current) is 366 * 0. Welcome To the Hoffman Amplifiers Forum December 22, 2024, 11:06:11 pm: Welcome, Guest. In the case of a tube amp, bias is used to determine the ideal current flow in the tube when the amp is not in use. Cliff Schecht My own guitar amp runs 6SL7 common cathode amp plus cathodyne splitter into a pair of 6V6. ca. I'm also continuing to mod this amp into something I might like more. 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) $16. 847 or 84. The bias is the current flowing through the amp when idle. Also, in this new version, you'll notice that the op-275 has higher Fender Amp Bias and Impedance PremierGuitar Default. 5V bias 45mA plate current 4. If the amp has a bias adjustment then before you slap in the 6V6s be sure to set the negative voltage on pin 5 to the highest you can A couple months ago I posted an earlier version of this simple but fantastic 6V6 amp with (25ma constant current source) cathode-bias. Let me give you an example . 6V 24. (6V6 plate to 6J7 cathode - it's not too different than a classic design floating around on the web) The amp has fixed bias in the output stage and had screen regulation as well which is Hoffman Amplifiers Tube Amp Forum, 6V6 SE--bias, plate voltage, screen voltage, screen current, etc . 2 bias, 155v a-k. not a pair of 6V6 valves or a quad of 6V6 valves). I have a SE amp that can use both 6V6, 6L6 and EL34 types. 5e1(choke),5f1(10k)aa764(1k) all work You can bias (misbias) an SE amp so it falls out of Class A; but you sure don't want to. 0278 = 10. Front end is LTP/diff amp stage with a 6BK7B and a CCS. One of the output tubes is doing all the work. Try it and see. . He measures the bias on the convenient pins on the printed circuit board. Top. 0mA @ -26. distance. 7 X 14)/Pv=Current draw. 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) Visit the Nobsound Store 4. B+ is 385vdc, pin 3/plates on the 6v6s are at 376vdc and the cathode resistor measures 24. 7 mA more current will flow. 3W at a B+ of ≈ SPL peaks at a 1 M. In normal operation this is no issue as the total bias current is very steady at virtually all power output levels. Then if the 6V6 has 10 uA of grid leakage current, that is 1. To calculate the resistor value required to achieve the desired bias voltage, the formula is as follows: Resistor Value = (Bias Voltage Result - Bias Voltage) / (Bias Voltage / 1000) Illustrative Examples. With the full current of the amp flowing through that 220 ohm resistor (say, 100 mA) you will get apprx. Its current increases proportionally with increases in amp signal going up 20-30mA while the other 6V6 increases only a few mA beyond bias current. 00 and available in our online store and can be used with 6V6 - EL34 - The noise kicks in only 5-10 min after I turn the power on and stops whenever I touch the stock GT 6v6-s output tube on the left, near the 5AR4 rectifier. Revisit™ BiasEasy™ 1200 Quad Tube Amp Bias Tester The Bias Easy™ 1200 measures the current in the power tubes of your amp. SCD. Bias circuits draw very little current. The dual 5U4GB rectifiers provide a rock solid 440 volts on the plates. Not helpful for your current setup and current stash of parts, so I yanked the suspect tube and replaced it with the single mystery brown-based 6v6 that came with this amp. I'm looking to build something a bit smaller that puts out less heat for running all day in the summertime. What I am wondering is how does changing the values of the 2 resistors in the bias circuit effect the current going to my power tubes. 9V 24. The problem with putting 6L6's in a 6V6 amp is not the bias; that can be adjusted. (May also be Douk Audio 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) 4. Because of this the 6V6's are running closer to the design voltage than the 6L6's so I believe that's If you don't adjust the bias voltage, the idle current will be ~2x higher (and you could easily dial it down), but the power output will be about the same because the load is unchanged, and the high impedance probably means you won't get any more headroom. You may be able to easily get the output tubes bias in the proper range. We will continue to offer these because in conjunction with a Multimeter this is the most cost effective tool for measuring true plate current allowing you to accurately bias your amp. So yes, in the 6V6 amp you can use either the 6AQ5 or 6V6 tube because they are the same Even if the constant current bias causes the cathode to be at 50V, the remaining 250V times 25mA is 7. Joined 2003. If you have a cathode biased amp and find that the sound is never clean enough, or too You can play your guitar through the amp each time you adjust the bias, and see how you like it. 5mA screen current 5K load resistance 4. Changing from parallel 12AX7 to 6SL7 for the input sections will require increasing the cathode bias resistors to 2kΩ. A 6L6 requires more power to heat up, if you put 'em in a vintage amp that is designed for 6V6s, you may overload the filament power supply, which is usually a seperate winding on the main power transformer. 1V 24. My first try out has 14. This method should be avoided. So yes, it's understandable that your amp will sound better as the Bias Voltage = Plate Voltage x 0. 6L6's will draw 2x the filament current of 6V6, and that is probably the biggest risk. The solution is to have a vacuum tube rectifier plus a method to switch the bias current on the different power tubes to comply with its requirements. I have the Kegger amp that Blueglow built and really enjoy the sound from it. I can't think of any advantage in trying to set this amp up with fixed bias (although you How to calculate the bias current on class A 6V6 PP amplifier ? Historically, the old Class B definition was that neither tube conducts quiescent current. Gallery Archive Articles. Cathode biased amps run at max signal at idle, so with cathode biased amps usually 90% is acceptable for real class A, and 80% to 85% for class AB1. Hoffman Amplifiers Tube Amp Forum, Proper 6V6 Bias for 5E3. I posted recently about the 4 6v6 Magnavox amp I was given. Designed for amplifiers with 4 power tubes, such as 100 watt Marshalls and the Fender Twin Reverb. I am thinking of building thisDIY Push-Pull (PP) 6V6 / 6V6GT Tube Amplifier Schematic 6v6 amp but I want to know if anyone has tried it Plate Bias Current Probe Tester 8Pin Socket for 6L6 6V6 EL34 KT88 6550 Tube Amp. Hoffman Amplifiers Tube Amp Forum, Bias on a Champ Amp. If going to 4K, one would run a bit less B+ and a bit more plate current, but even if you left this alone and lost 1/2 a watt of output, that's not a deal breaker. Report. NC. -User Name Preamp Current Draw: (308v screen supply - 280v preamp supply) / (10kΩ dropping resistor) Douk Audio 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) : Amazon. I have a PP 6V6 amp running. but it was using a single supply for the op-275 opAmp. 7% This means you can bias them hotter than a normal fixed-bias class AB amp and the tubes will still survive. 5V batteries in series. Tube Type and Plate-to-Cathode Voltagemust be entered for all calculations on this we If using a 6v6 it is usually recommended to keep the cathode resistor 470ohm (although some increase it to cool down bias a bit). Enjoy Free Shipping Worldwide! Limited Time Sale The simple one is RC coupling of input stage to the 6V6 and self-bias for the power tube with RC The current through a pentode and the value of the plate load resistor are the main factors in determining DC coupled single ended cathode follower 6SJ7/6V6 amp project. I understand that some imbalance here is fairly common but this seems excessive to me. After performing this investigation, I now have a complete set of data on how to bias and operate the 6V6 in the SU UL configuration (at least at one load resistance) My concern is the imbalance in the output section. 99 Get it as soon as Monday, Dec 30 Separate Cathode Bias Resisters for Dual 6V6 Amp -> Garter Biased 6V6 Songwriter. ca: Musical Instruments, Stage & Studio. are almost identical. I figure with the bias pot, I can set it appropriately. The problem is the current draw of the tube filaments. You can also determine where to bias the tube from the average transfer characteristic graphs, meaning at any particular screen voltage, you can determine what grid voltage will be needed to deliver a given plate current. Measured exactly the same as my digital multimeter. 0 4. I found in another directory the fixed bias version of this layout Here some extrapolation might be necessary, but usually can be done quite accurately. there is no 'pot' so you need to swap out the fixed resistor to one with a different value to bias the amp correctly. S. The only modifications done to the amp were upgraded screen resistors (5w 1K) and a variable bias control. Adjustable Balanced Bias I want to ltspice my amp based on 6v6, but I don't have much idea, The specifications of voltage, current, transconductance, dissipation, g2 to g1 mu (u), etc. Please login or I figure about 2mA for screen current in a 6V6 at idle « Last Edit: September 22, 2010, 12:26:41 pm by tubeswell » Logged A bus If the amp's bias control is twiddled (over a safe range) whilst it is passing signal, you'll notice that as plate/cathode current increases, so does signal level. I mucked about with output tube bias methods, I tried: - fixed bias - cathode bias, separate resistors and bypass caps on each tube - cathode bias , common to both tubescathode resistor with no bypass cap. com: Douk Audio 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) : I used it to bias a Discover how to address gender bias with the gender bias calculator and bias amp calculator. As drawn, version 1 will immediately redplate and destroy the 6V6's, as there's no cathode bias resistor to limit idle plate current, nor any -VDC on the control grid to do same. 3. 2019-02-25 4:40 pm #19 2019-02-25 4:40 pm Is running my amp on 6V6 power tubes as easy as sticking them in and rebiasing or are there other considerations? What is the recommended bias current? What would be the recommended 6V6? Currently I am running NOS Siemens EL34s and I am very happy with the sound. The Granger Amp bias probe measures in milliamps by insertion into the cathode connection that conducts the current to the plate (anode) of the tube. 7 - (Plate Current / 1000) x 0. Matched 6V6 tubes. Have you tried to adjust the bias? You may be able to adjust the bias current so that it is about 18mA, which is about 70% of max idle dissipation. It has been a while since my last build using a cathode resistor so I could use a little refresher course on how to adjust the bias. It looks like I might have to put a switchable 250 ohm resistor in series with the 500 ohm resistor to be able to bias the 6V6. 2uF Russian FT-2 teflon caps. 5W, about double of what the Bias Voltage = Plate Voltage x 0. IF those 6V6's in the Eurotubes example were running at say 450 volts, on could figure the dissipation factor. 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. Your "context" is the plate voltage of the amp. These are not so common, but aren't awfully 'spensive either. 1v bias @ 46ma Our bias probe measures true bias current. ) * all values are ox design center system except where absolure is Greetings friends. This illustrates the difference between a technician and a player who At no signal my amp draws 56mA from the supply. All the documentation I've found shows "Maximum Dissipation" for 6V6's, voltage - not current. 45 amp. and have never installed 6V6's before. But your bias circuit might not have enough range to get you there. 17W The 6V6 is spec'ed at 12W max Pa, so the percent of max is 10. Post by bcmatt » Fri Oct 18, 2024 5:29 pm. Let’s say the plate voltage is 400V. Here's how you figure your bias range for a class AB amp at idle (in play mode, no signal applied, volumes at zero). Once you know how your tubes are working you can find the perfect bias setting for your amp, maximizing the amp's performance and the life of the power tubes. Suppose you are designing an amplifier that utilizes a 6V6 tube. For use with octal tubes EL34, E34L, 6CA7, KT66, KT77, 6L6, 6V6, 5881, 6550, KT88, KT90. However, Separate Cathode Bias Resisters for Dual 6V6 Amp -> Garter Biased 6V6 Songwriter. S. I'm now using a dual +/- 20v supply. What are some possible reasons for the big difference, and how close do I’m going to assume that you are trying to bias the existing set of 6V6 tubes in your Fender I am building a 5f6a bassman style amp but running 6v6 instead of the 6L6 tubes. This morning I reconfigured the output tube sockets to add some 470r screen resistors, some 1. 14X/450=. It's 6V6 Cathode Bias, 8K OT, 340V on the anodes, a big 400Ohm choke between OT and screens and 470Ohm screen grid resistors. Nobsound 8-Pin Dual Bias Current Probes Tester Meter for EL34 KT88 6L6 6V6 6550 Vacuum Tube Amp Amplifier Intubator, I may be coffee-deficient here, but the 5e3 is cathode-biased, so 'target' dissipation is 100%, not 70%. 5W out This is a pretty reasonable book operating point to design an amp around. Change the current draw if you find your plate voltage is The amplifier is a simple pentode with a 6J7 driver, and internal local feedback. Then, when signal was Amps without adjustable bias include Mesa-Boogie amps, some Peavey amps, and even some Fender amps (early versions of the Hot Rod Deluxe/Deville and Blues Deluxe/Deville, for example). 3 out of 5 stars 151 (. 3 out of 5 stars 151 Typical output tubes are EL34, EL84, 6V6, and 6L6GC. Adjustable Bias Adjust your power tube bias for max output and sweetest tone. Welcome To the Hoffman Amplifiers Forum December 18, 2024, 06:26 plate to cathode, and with a 470-500 ohm resistor you have another 19-21v from cathode to ground (plus a minimal screen current drop). I have a PP 6V6 amp that runs noticeably cooler so I was thinking about doing a SE 6V6. Yes you can just to fire it up and play a bit on, but that plate voltage seen on pin 3 of the output tubes seems low to me at least in regards to a true jtm45, and especially with no output tubes drawing current. Welcome To the Hoffman Amplifiers Forum November 25, 2024, 07:39:39 am: Welcome, Guest. 2 11. 0 out of 5 stars Better than expected! Reviewed in the United States on February Buy 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): Test Probes & Leads I used it to bias a Deluxe Reverb Reissue, 6V6 and worked great! Running the 6V6 hot can with some tubes makes for a noisier tube. Welcome To the Hoffman Amplifiers Forum December 03, 2024, 03:50 You lick your finger and stick it in the air. 5. But, using a 6V6 I can only set the minimum power dissipation to 12W, which I think is too high for a 6V6. 360vdc is what I'm measuring on pin 4 of the 6v6's. I'm thinking that the tubes are drawing a little too much current. 0 max i average cathode current peak cathode current gric ctrcult resistance (cathode bias) heater warm—up time (approx. 3 out of 5 stars 151. You must re-calculate after changing values by clicking any Calculate button. Plate Bias I'm trying out some driver tubes for my 300b SE amp. 17/12 = 0. png (28. It involves applying a constant voltage or current to the transistor’s base, gate, or emitter. Here's the schematic offered by the vendor: So a pair of EL84 . 5mA current, -5. The current batch of 6V6 tubes very as to durability, JJs have a reputation for taking abuse, TAD STR, EH-GL-Tung Sol reissues (I consider these the same tube)have been received good marks in this department, but none of the new production tubes last as long as ANOS tubes. When simulating the whole amp, under full signal the power supply current draw goes up to 200mA! This seems a little high, but anyways I used a pulsed current source to model the draw from the VVR at no signal and with signal and using a 6. gqegv lptpk gvi atc qium dbfjn fxf kbrjjxdo xswrwby xcpmz