6l6 push pull amplifier schematics. Here's what I've got so far: -2 pcs.

6l6 push pull amplifier schematics. If you decide to replace the 6V6 tubes with 6L6 tubes this transformer as well all other circuit Push-Pull Tube Amplifier Simulation The results below present circuit simulations for a push-pull pentode 2-tube power amplifier. Nov 23, 2018 · Favorite Push-Pull 6L6 Scuffle. They all "scoop" the mids somewhat, even if it has a mid control that is set at max. GIF This Class-A Push-Pull Tube Power Amplifier uses a Pair of Push-Pull Class A, Ultra Linear Mono Block Tube Amplifiers that can be used with several different vacuum tubes including KT77 / 6L6GC / KT88 with a 12SL7 driver and 6NO30 tubes. A 20 watt 6V6 Class AB (push-pull) 2 channel footswitchable head, with is a high gain lead II design based on John That sort of thing. Is this supposed to be a class A push pull amp? Or was your intent to build a class AB amp? You'll get more power with a class AB amp, but you'll also need more B+ voltage to do it. all-audio. Here is a longer dissertation of the amplifier theory that I wrote up: Go To Tube Amp Theory Page I found a variety of different amplifiers that homebrew builders made. This index has a wide collection of Vacuum Tube or valve circuits or schematics, OddBlocks - Class-A Push-Pull KT88 Tube Amplifier (12SL7 Driver). Because you like Electronics. The amplifier schematic is very similar to the one I used for my very first tube amplifier. Diy push-pull (pp) 6v6 / 6v6gt tube amplifier with hammond transformersPush-pull (pp) el84 (6bq5) or 6v6 (6aq5) tube amp schematic with dynaco Tube 6v6 pull push schematics schematic amplifier amp pp guitar vacuum 6sl7 Return to Homebrew Radios and Equipment. A Pair of Push-Pull Class A, Ultra Linear Mono Block Tube Amplifiers that can be used with several different vacuum tubes including KT Sep 7, 2009 · Hi Can anyone recommend a simple, proven schematic for a 6V6 amp? I'd like to use 12AT7 or 12AX7's as drivers. I fear that even if the guy replaces the transformer with a new Jun 2, 2019 · For somebody reading this thread wanting to build a nice push-pull amp amp from the Golden Age of Audio, you can also refer to the Eico HF-87, a true audio classic. Amplifier & Power Supply Sep 29, 2011 · A google search turns up the following: a 6L6 power amplifier DIY Audio Projects Forum • Williamson 6SN7 - 6L6 (KT66) Tube Amplifier The EF86+6SN7+6L6 push-pull circuit - Amplifier_Circuit - Circuit Diagram - SeekIC. Users browsing this forum: Google [Bot] and 6 guests. I recently went through my desk drawer, which holds a good few years of scattered schematics, and I'm kinda suprised at how much I knew Nov 16, 2024 · 6l6 Push Pull Guitar Amplifier Schematics - Use aThe power amp has a pair of 6L6 beam power tetrodes in a push-pull configuration, from which we can expect a lot of power. Here's what I've got so far: -2 pcs. From mid 80's I went back to tube amplifiers and tried to build a 30W 6L6 push-pull mono block pair with 6SN7 drive tube. Preferably use a matched pair or a same brand / same lot pair of 6L6’s in each channel , because the quiescent current is high ( about those clips sounded very nice for sure. The components in this circuit will never produce 25 watts and is much more expensive than the 10 watt output transformer. That is, I took out the power Apr 23, 2021 · all-audio. The MAP-15 design thus offers an interesting feature: a push-pull 6L6 power amp that is designed to break into overdrive at substantially lower volume levels. Let's take a closer look. The bassman was a combo amp in the tweed era with the 1×15″ and 4×10″ speaker configurations. but getting back to my previous post, what are some examples of cathode bias push/pull 6L6 amps? and does anyone have any experience with 6L6's in triode mode? If you are going to do a stand-alone power amp for use with a variety of preamps, then in my opinion, it should be made as versatile as possible. I used a push-pull-parallel set of 5B/854M tubes, which are basically 807 tubes in a slim bottle with a loctal base. Push-Pull Driver Circuits Driver circuits here mean low-level input or driver amplifiers, not power amplifiers. Sep 4, 2019 · If you can source a good pair of output transformers with screen taps, you could recreate an original Williamson amplifier modified for Ultralinear operation. bought Jun 20, 2011 · The EF86+6SN7+6L6 push-pull circuit is shown in the figure. Jul 24, 2016 · Our collection of Hi-Fi Audio Schematics. A Pair of Push-Pull Class A, Ultra Linear Mono Block Tube Amplifiers that can be used with several different vacuum tubes including KT Dec 22, 2018 · Poddwatt: Class-A Stereo Push-Pull EL84 (6BQ5) Vacuum Tube Amplifier. May 15, 2006 · Hi quitvinny , As I said , this 6L6 PP Class A schematic is a classic and the correct Zout , that is the total load ( plate to plate ) is 5000 ohms , and the +B correct value is 270 – 300 Volts . Mar 2, 2023 · Circuit board for building the 6L6 push-pull aTube amplifier from Electrosonique . Dec 31, 2024 · It depends. Only some specific values for components were given. The 6L6 push-pull amplifier schematic is a popular and versatile option for guitar amplifiers. Apr 14, 2017 · I would like to make two monoblocks with a 6SJ7 voltage amp, 6SN7 LTP and a quad of 6L6GC in push pull, run on approx. That's a classic using 6L6 type output tubes and 6SN7s. The tube is popular in hi-fi vacuum tube audio as a low noise line amplifier, driver and phase-inverter in vacuum tube push-pull amplifier circuits. Oct 16, 2022 · Ketjie, That is a very interesting simple push pull amplifier. All models have a push-pull (class AB) dual 6L6GC power amp configuration. Power 20W. Just pick your poison 🙂 My opinion? Start with a push-pull. Offer a dormant project of a tube amp with building instructions. Nov 14, 2013 · Parallel push-pull just means twice the current at the same voltage, so half the impedance. A similar schematic uses the 6SL7 as a 2 stage driver, I might try it wired both ways. I selected a popular circuit diagram see picture: As an attempt I wanted to build a tube power amp to see if I could find that good sound I heard when I was young. 5 250ohm shared impedance: 9,000 output power: 24w If i were to ha e 425V at the plate and fixed bias I'm guessing 60-75ma per tube and maybe 30 watts? Just a rough Hunting a 6L6 push pull amp schematic Thunder 30 — Drop-in Upgrade! Cord length is a super-long 15 feet, cord thickness is 0. 3v 6A to heat 6SJ7 and 6SN7) - for heater power of 6L6 quad a Hammond 266S6 (6. There is also a huge library of effects and solid state schematics. 26 followers. Push-Pull /6L6 Amplifier. 300,275,250-0-250,275,300 @ 250mA and 6. Nov 10, 2019 · Oddwatt 225: KT77 Push-Pull Tube Amp - 19 May 2008 - Superseded, see OddBlock Class-A Push-Pull Tube Amplifiers. Now we have reached the part that can make or break an amplifier design. Apr 21, 2023 · Push pull designs, (great for 6L6 tubes!) require more components, but you gen more output power and cheaper output transformers. Variable NFB on a dial with a push-pull switch to defeat it altogether, cathode/fixed bias switching, bias circuit that can handle 6V6/6L6/EL34, pre-pi and post-pi master volumes. I've got a stereo amplifier chassis with a pair of push-pull OPTs with a 5K primary, three sockets per channel 2 for 6L6s and one for a dual triode. With the adjustable bias you're talking about it would be an awesome amp to try different tubes/bias in. Web here are the schematics for my 6l6 ultra linear amplifier that is the power amp in my main system. ch This index has a wide collection of Vacuum Tube or valve circuits or schematics, OddBlocks - Class-A Push-Pull KT88 Tube Amplifier (12SL7 Driver). com Not surprisingly, Pete Millett has a 6L6 design as well: Push-pull KT88 class A amp with "universal" driver PCB Rather than expecting everybody to bend over and hand you a The amplifier schematic has been redrawn to reflect my preferences. Hum is independent of level Category: 6l6 push pull amplifier schematics The LM is capable of providing extremely good load regulation, but a few precautions are Continually monitors battery voltage during use and consumes only about ? Schematic for 6l6 Single Ended Amplifier with 6N3P SRPP Driver Amp, Valve single end power amplifier circuit Valve Amplifier, Diagram, Circuit, Tube. 29% Tube Complement : 1x 6J5 (input), 1x 6SN7 (differential phase inverter), 2x 6L6GC (output), 1x 5R4GYB (rectifier) The Output Transformer : Jun 2, 2019 · For somebody reading this thread wanting to build a nice push-pull amp amp from the Golden Age of Audio, you can also refer to the Eico HF-87, a true audio classic. Nicola Pavan. - as power tranny I would use a Hammond 378CX (400-0-400v 534mA, 6. Is the amplifier current draw relatively steady all the way to full output power? Mar 9, 2025 · The 6L6 push-pull amplifier schematic is a popular and versatile option for guitar amplifiers. bmp Push-pull amplifier with 845 tubes for Altec systems by Sakuma 845PP_1. The PCB also includes a tube-based power supply, using 5U4 or whatever tube you like, and snap-mount capacitors on the PCB. Its only downside is that it needs a separate negative voltage supply and a constant current sink to feed the tail of the LTP phase splitter (and perhaps the second differential amplifier). 5kHz. The OddWatt 6SL7 SRPP / KT77 SIPP Class-A Ultra Linear DIY Tube Amplifier Project. Jun 19, 2024 · Is it a single ended amp or push pull? How is the output stage wired—triode, UL, or pentode? If Pentode what is the screen voltage you are using? What amp is this? Got a schematic? I've drawn an awful lot over the years (gosh, come to think of it, I'm coming up on my 10th anniversary of getting a soldering tool :), from Doom levels to mechanical contraptions to metal-melting devices to electronic circuits. Apr 2, 2024 · WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES. Included are schesmatics for diy amplifiers and for some popular vintage Hi-Fi Audio Components. LTPI vs Cathodine needs to be decided and it can be either. OddWatt 212: Push-Pull EL84 (6BQ5) Tube Stereo Amplifier - 22 October 2007 - Superseded, see Update. But the problem seems to be a bit different May 7, 2011 · Today we’ll look at some of the more interesting audio-circuit plans and schematics from the first two years of Audio Engineering magazine. Is the amplifier current draw relatively steady all the way to full output power? Schematic by David Hafler & Herbert I. Aug 11, 2011 · hi everyone, my name is mike, i come from a small country called new zealand- i am currently planning to build a 6l6 push pull stereo power and pre amp using 12ax7s in the preamp and driver stages and have had real trouble finding a schematic that has been tried and proven using the above Jun 16, 2017 · As of lately I've been sourcing some parts for a new project after last years build of a Baby Huey. I selected a popular circuit diagram see picture: Stage 1 voltage amplifier calculation. And they all have Bass and Treble controls. You may want to look at the Brown era. A poorly designed output can make an otherwise good amplifier sound terrible. Dynaco Push-Pull EL84/6BQ5 or 6V6/6AQ5 Tube Amp Schematic. May 15, 2024 · Does anyone recgonize this 6L6 push-pull stereo amplifier with 7199 drivers and a 5AR4 rectifier? It was given to me and I have had it for years and believe it is missing a bias rectifier as only Web The Output Stage (See Schematic) Consists Of 3 6L6 Tubes (Common Cathode) In Push Pull Mode. This is a 6L6 or KT88 family amp that was an effort between Kegger and myself to try a different triode-pentode driver tube in a cathodyne configuration. Check Tubelab's SPP here, it is very popular, relatively cheap, well regarded, and a ton of support here for your build. OK, the frequency is a very little higher than that, because of the 6SJ7's parallel plate Dec 23, 2010 · Schematic for 6L6 push-pull amp Homebrew Equipment Apr 13, 2021 · Now I can say without a doubt in my mind that my scratch built 6L6 Push Pull Stereo Tube Amplifier is finally complete with proper voltages and all!! All recycled parts. I gutted out the electronics and pulled the necessary components. Keroes. N. Dec 1, 2015 · Hello all, Just finished my new 6L6 Push-Pull amp but I have too much of hum in my speakers. I'd appreciate any input that members might have regarding this circuit. These are simply the combined anode characteristics of the stage, as if the two valves in the circuit are rolled into one big valve (which as far as the output transformer is concerned, they are). I've got a critical amplifier chassis with a pair of push-pull Flocks with a 5K primary, three scientists per channel 2 for 6L6s and one for a woman triode. Schematic by Rainer zur Linde from his book Dec 1, 2015 · Hello all, Just finished my new 6L6 Push-Pull amp but I have too much of hum in my speakers. (and I do not really like almost all concertinas). Thanks in advance Jul 9, 2014 · All of the push pull BF/SF Fenders have a tone stack IIRC. The output transformer is a hamondP-T160 at 10W instead of the 25 watt transformer in the ordinal schematic. The amp is a kit (not chinese,is from Germany) ,I bought the power transformer and OTs , the tubes , and then I made the assembly according instructions. Power : 10W RMS for 700mV RMS input, with a THD+Noise of 0. The following document contains the tube amp I chose as my first tube amp. From mid 80’s I went back to tube amplifiers and tried to build a 30W 6L6 push-pull mono block pair with 6SN7 drive tube. Any of the fixed bias setups can be run using cathode bias instead. With its impressive muscle and superior tonal characteristics, the 6L6 has been a staple of music production for decades. Dec 23, 2019 · It is an incredibly powerful and versatile way to generate a huge range of sounds. bonavolta. In my push pull cathode bias amp I did try using a 6v6 in one socket and a 5881 in the other. The tube uses a 6,3V heater which needs 0. This tube amplifier is scaleable and can be used with 6V6, 6CA7, EL34, KT66, KT77 and KT88 output tube. It is at about 5. 400V on plate and little less on screen. Favorite Push-Pull 6L6 Schematic? Ads are not permitted. 2. Jan 14, 2007 · One of my questions lately too, besides others, does anyone have a great link to a DIY project or schematic or brand/name/model of any great amp using 2 6V6's in push-pull, with some audio control pots, etc for a decent guitar amp? I'm seeing at lot of circuits on places like Duncan's & MachMat Oct 6, 2015 · 6l6gc Push Pull Schematic To the right are a schematic (above) and a diagram for a possible layout which is about 20 Watts, with a 6. There are opinions which indicate that this popularity is caused by audiophile industry/media polarization, not by its performance. Hum is independent of level May 15, 2024 · Does anyone recgonize this 6L6 push-pull stereo amplifier with 7199 drivers and a 5AR4 rectifier? It was given to me and I have had it for years and believe it is missing a bias rectifier as only Web The Output Stage (See Schematic) Consists Of 3 6L6 Tubes (Common Cathode) In Push Pull Mode. Established If it were a higher rating the transformer would overheat. Up to the blonde Bassman with blonde colored tolex (circuit 6G6) they all had tube rectifier, but since then a diode rectifier was used. Below is an amplifier schematic from the 1955 Acrosound catalog: The 5B6 Bassman is a 2-knob (vol & tone) amp that uses push-pull 5881's in cathode-bias, and octal preamps. gif Audio Research SP8 preamp audio_research_sp-8_schematics. I used russian tubes. May 13, 2014 · Does anyone have a favorite push-pull 6L6 schematic? I've got a stereo amplifier chassis with a pair of push-pull OPTs with a 5K primary, three sockets per channel (2 for 6L6s and one for a dual triode). Something like 400V to get 20 to 25 watts output with a 6. Extra plate current feedback is produced by the 120 ohm unbypassed cathode resistors. Web push pull 6l6 mono 6L6 PP1 from www. To drive my not so efficient Scan-speaks I aimed for a pair of bigger bottle tubes and around 30 to 40 Watts. 6k output transformer. The amp is a pushpull of 6l6's ; the manual recommends to bias each tube at 35ma; I want to use 6L6 GC tubes instead; should I keep the same biasing or what is the optimized operating point per tube for a plate supply of Mar 14, 2001 · Push-Pull Outputs. 6 kOhm output transformer and a 6L6 push-pull pair. More information DIY 6L6 KT66 Single Ended Amplifier with 6N3P SRPP Driver. May 21, 2008 · Anybody knows where to find an impedance infor for 6L6 in P/P triode mode in different plate voltages? Looking for 6L6 push pull impedance in class a Triode mode @ 450V. Use a output tranny that can “hand” 25 Watts or more . 6g3 Deluxe 6L6 Push Pull Amplifier Schematics. pdf Single ended tube amplifier with Western Electric 212 212 amp. When a differential amplifier or any other kind of amplifier using a push-pull arrangement is used matched tubes are helpful in reducing distortion and drift. The Microcap simulator was used to produce the graphs for a signal frequency of 1kHz. A unit which has been properly designed from phono input to power output will give that wonderful tube sound that makes listeners mouths drop open in amazement. Pictured above is a great lil’ amplifer (approx. Dec 12, 2021 · Re: 6L6 Circuit by JJH0906 » Thu Dec 16, 2021 1:41 pm Attached is a schematic from another popular amp building book for a Push-Pull Class AB output stage circuit. i especially liked the whole lotta love tone. The result is:- [1] The distortion in the output stage is reduced by a factor greater Feb 7, 2025 · Hunting a 6L6 push pull amp schematic. This looks quite nice - and remember that a 7N7 is equivalent to 6SN7, so tubes are exactly what you want. May 25, 2024 · Push-pull (pp) el84 (6bq5) or 6v6 (6aq5) tube amp schematic with dynacoPush pull 6l6 schematic amplifier 10w output power input 6v6 circuits schematic push pull amp tube diy pp using 12at7 magnavox audio amplifiers radio which stereo power build chooseLooking for any 6l6 designs. 807's or 5933s can be substituted, as can 6L6 tubes or even 829B tubes. There's also another scooter for what is currently a 5V4 rectifier, but could be bad with another dual triode and a unity rectifier Dec 16, 2021 · Last edited by JJH0906 on Tue Dec 28, 2021 11:57 am, edited 1 time in total. Some also have Mid control. This provides about 20 db of feedback over the 6L6 output tubes. Amplifier & Power Supply Aug 20, 2024 · I don't build them like this, so haven't even simulated a 6L6 push-pull with these specific values at the cathodes. Founded in PowerVolt grew steadily, quickly acquiring a strong reputation for it's high standards of quality and reliable products. If you see a problem with any of the schematics, please email me so I can fix the problem. I selected a popular circuit. A few other thoughts: You need a bit more B+ voltage regardless of the desired power output, since you really should be Dec 12, 2021 · Re: 6L6 Circuit by JJH0906 » Thu Dec 16, 2021 1:41 pm Attached is a schematic from another popular amp building book for a Push-Pull Class AB output stage circuit. 30watts) that uses a single 6AS7G tube for push-pull output. Amplifier & Power Supply Klimo preamplifier Klimo. pro › the-push-pull-amp. Consider, for example, the signal path from the Harvard 5F10's phase inverter to its output transformer primary. More information. but getting back to my previous post, what are some examples of cathode bias push/pull 6L6 amps? and does anyone have any experience with 6L6's in triode mode?. Dec 11, 2012 · why can't someone convert a schematic and show a newbie non-schematic reading person how to build a tube ampsee below for what I meanIt shoudl NOT be rocket science based on the insides of other push pull amps I have seen sowhy can;t someone spec it out for newbies ? :D Feb 4, 2015 · 425V B+ 6L6GC 4k center tapped ot Push pull class A Fixed bias TDSL says this for cathode bias: B+ 360 Vg2 270 Ia 50 Ig2 9. Tube amp Schematics index page There are over 3500 Tube amp schematics and other types of schematics in the EL34World Schematic library. There's also another socket for what is currently a 5V4 rectifier, but could be replaced with Aug 20, 2024 · I don't build them like this, so haven't even simulated a 6L6 push-pull with these specific values at the cathodes. The schematic works by using two 6L6 tubes wired in “push-pull” operation. 6L6 Single-Ended 1. Seemed to work just fine with the tubes biasing up different. build a 30W 6L6 push-pull mono block pair with 6SN7 drive tube. For the tube amplifier circuit I used a cutoff pentode (6SJ7 or 6SD7) driving a beam power pentode (6L6 or 5881) in a single-ended circuit (class-A operation). There are a few minor deviations from the original schematics. 3V @ 5A Dec 21, 2009 · DIY Push-Pull (PP) 6V6 / 6V6GT Tube Amplifier with Hammond Transformers DIY Push-Pull (PP) 6V6 / 6V6GT Tube Amplifier Schematic This 6V6 amp was built following the push-pull (PP) EL84 / 6V6 Dynaco A-410 output transformer schematic. It also means a greater load on the previous stage; mainly Miller capacitance for UL and triode-mode. That dominant pole, the series 270k pentode load, 100pF cap, and 20k to ground is also interesting. I designed a driver PCB using two 6SN7's that can drive just most tubes, triode or pentode. They're typically 40% less than the plates (I've always been a little fuzzy on if it's 40% of the . This amp was designed mostly to work with KT88, 6L6, or EL34 tubes in either triode or ultralinear mode. Jun 22, 2017 · I would like to build a few monoblocks. This is a pair of monoblock amplifiers that I built using the Push-Pull driver boards (described in more detail here). Oct 24, 2004 · Hello, I've just bought a pair of monoblocks made by Antique Sound Lab. …. Could anyone recommend a good circuit/schematic for a push pull 6L6 unit? Looking to get 25w or so out of them Apr 23, 2021 · A push—pull amplifier is a type of electronic circuit that uses a pair of active devices that alternately supply current to, or absorb current from, a connected load. Above is the shunt regulated push pull driver stage with single ended 2A3 output. Feb 25, 2011 · I'm trying to wrap my head around the design procedure for push-pull class AB1 power amp stages. Jan 31, 2013 · When the resistive load of push - pull amplifier is 5kΩ, 6L6 amplifier tube is in the class A push - pull state, screen voltage is 280V, and when the signal changes to the full signal from zero, the screen current change is 120 ~ 140 mA, and output power is l5W. Big bottle (6L6/EL34/6550/KT88) amps are more typically fixed-bias to produce more power than an equivalent cathode-biased design. Schematic for 6l6 Single Ended Amplifier with 6N3P SRPP Driver Amp, Valve Amplifier, Stereo. I'm thinking about how to design using a specific transformer: Hammond 1650RA, 5K @ 100W So if I understand correctly, in a push-pull configuration, each tube would see one half of the output Apr 10, 2019 · Im not sure what people think about this Amp but its more about the sentimental value to me and the learning process! (priceless ) So I started working with troubleshooting a channel imbalance on the schematic attached, 12ax7 + 6L6GC push pull. I especially like that 6V6 concertina with the two 10k resistors. Masco's design does not use screen resistors to protect the tubes from the effects of overdrive. Building, troubleshooting and testing of these amplifiers should only be performed by someone who is thoroughly familiar with the safety precautions around high voltages. Just for the fun of it. Feb 1, 2013 · 10w 6L6 Push Pull Amplifier Schematic Frequency Response : 15-65Kc (-3dB), 1Kc input, at 3W RMS output across 16 ohms. Any valve textbook describing how to design a push-pull stage will explain how to draw 'composite characteristics'. Dec 23, 2010 · Schematic for 6L6 push-pull amp Homebrew Equipment Hoffman Amplifiers Tube Amp Forum, How to calculate push-pull impedence? The total plate current on either side of the push-pull class A amplifier is sensed in a 27 ohm resistor. Ah yes, electronic circuits. Sep 9, 2014 · The tube amplifier replaces a solid-state amplifier which was driven by a tube preamplifier. jpg Radford STA15 amp radfordsta15. SRPP / EL84 (6BQ5) Tube Amp Schematic. 4,000 ohm to 4 or 8 ohm for use with a single 6L6, EL34 or two 6V6s in parallel. Single Ended Tube Power Amplifier Having listened to push-pull amplifiers all along and very satisfied with the sound quality, because to me a tube amp sounds like a tube amp no matter what, I decided to try to build a single ended tube amp. I start with an old Montgomery Ward mini console. 3v 10A) With a push-pull power amp, there are balanced signals represented by voltage differences. Tabs anyone have a favorite push-pull 6L6 sensible. Has both 9 pin and 8 pin output tube sockets for running EL 84 or 6L6 type tubes! 10 watt. 29% Tube Complement : 1x 6J5 (input), 1x 6SN7 (differential phase inverter), 2x 6L6GC (output), 1x 5R4GYB (rectifier) The Output Transformer : Nov 24, 2020 · I think the best topology for a push-pull tube amplifier is the one described in the push-pull Class AB2 6L6GC amplifier thread. Posted: May Tue 13, pm. Schematic by David Hafler & Herbert I. The amplifier stage is based on the Compact Hi-Fi Power Amplifier. The power tubes are standard 6L6 pentodes. With a push-pull power amp, there are balanced signals represented by voltage differences. lbx9kp faa wwt hzs s7et aoqu8l or aixy y5vu8 9k1bk