I'm looking to build an amp with a decent amount of clean headroom to play both at home at low volumes and also with a few friends (drums and bass). I would like to have a decently clean amp for testing out pedals, and I want to have enough headroom to stay relatively clean while playing with drums. Anyone have any good suggestions for what I should be looking for? I was initially thinking something with four 6v6's as the output stage. I have a couple of These that I've had for years, so I was thinking about doing a 1x12 setup with one of those. They're fairly efficient speakers, so I was hoping I could get away with a lowish power amp and still get a decent amount of volume before breaking up. Does this seem reasonable? If so, can anyone recommend a clean amp design with good tone that would fit the bill?
Agree on Jazz Chorus...I have a few Jazz Chorus JC-120 Preamp Stage PCBs I had done that you can put in front of a tube amp (or a SS amp) of your choice...I put one driving a LM3886 Chipamp and another driving an Icepower 200ASC Module. Both amps rank. Also had one driving a Magnevox tube amp (12AX7 / pair of 6V6 for about 10 watts)....not bad, but preferred the SS.
Free PCB - I have a few left.
Free PCB - I have a few left.
That sounds great, honestly. I'm guessing I'd need to put my own parts on it. Do you have a BOM as well?
dude if you want something that is going to match what's going on in your parts box smoke an another one i've two rooms of plethora parts i've kept on the disillusion that someday they will be usable for some project PM if you will...
Yes, I have the PCB, Schematic and BOM to send - Just make a simple donation to DIYAudio site and $5 to mail it all to you...
What is wrong with a 12A*7 preamp stage into the 6V6's? I bet thousands have been made by now. Not rocket science.
Lots to cover here. If you are just looking for suggestions regarding what amps are clean with plenty of headroom AND have the volume needed to compete, you'll need something probably above 50W in my experience. Although volume doesn't increase by double when doubling power, clean headroom definitely increases.
The Jazz Chorus is considered by many to be tops for clean, but is SS. How about a Twin Reverb? Loud, clean, takes pedals well. JTM45 with high plate voltage? Hiwatt, Ampeg, Traynor, Dual Showman, John Mayer Signature Two Rock, Matchless, and many, many more. Actually, there are so many out there that you will get more ideas faster if you just do a web search for guitar amps with clean headroom.
If you are trying to understand what accounts for clean headroom in a tube guitar amp, study the schematics of examples. It can be a complicated mix of factors; preamp, PI and output tube plate voltage, output transformer design, bias setting of preamp and output tubes, amount of gain, number of gain stages, tone stack design, controlling gain all along the signal chain. The amps I most often build are Trainwreck-style amps that push the PI and output tubes hard. OTOH, Marshall designs often produce lots of preamp distortion before the PI. The D-style amps I have produce lots of clean tone with the proper settings. Not sure you will get enough clean volume with a pair of 6V6 tubes, but possibly with four. Try looking for designs with 6L6GC output tubes.
You'll need an efficient, preferably high-wattage speaker as well - something like EV12L or EV12S, some Celestion models or other brands with ceramic speakers. A single 12 cabinet can be stretched playing with bass and drums. A 2-12 might serve you better when playing with others.
Have fun!
Maybe I am just more of a SS guy... I have had the JC-120 and the JC-77 (still have the 77) and love that clean SS sound... I'll even throw in those cheap SS Peavey Bandits, they sound great too. Currently use a Peavey Special 130 (basically a Bandit on steroids) in the band I am in....and I came from a Fender Hot Rod Deluxe...don't know why the HR just didn't do it for some reason. Tried mods and tubes...not bad, but just something... but never tried a Twin or Deluxe Reverb.... I actually have DR near complete - just need a nice quiet weekend to finish it...
But I am still on the fence as to whether that cool, lush tube distortion comes from the Input tubes, Phase Inverter, or output tubes...
But I am still on the fence as to whether that cool, lush tube distortion comes from the Input tubes, Phase Inverter, or output tubes...
Tube amp distortion definitely has a particular character depending on where it originates in the circuit. They can all sound good, or if implemented poorly, not good. Second order vs. third order distortion also matters a lot.
Give a properly-functioning Twin Reverb a try - it's really too loud for most players these days, so will be used at lower, cleaner volumes most of the time.
One of the more popular clean amps for jazz guitarist i know is the Polytone Mini Brute, that is basicly an opamp based guitar amp. But those i know says it sounds better than the Roland Cube or the JC120, and especially with acoustic guitars with pickups the way to go as it's real neutral in sound.
Some 15 years ago I bought a Faylon BK30 instrument amplifier. Faylon was a Belgium manufacturer of instrument amplifiers which was active in the first half of the seventies. Among the bands that used Faylon equipment was "The Golden Earring", a Dutch band known for their hit single "Radar Love" (1973).
The amplifier sounds very clean and is very quiet (noise/hiss wise). There's local feedback in the first stage of both channels (something you hardly ever see in tube amplifiers for instruments) and the power stage uses GNFB and a Philips AD9047 UL OPT which was intended for Hi-Fi amplifiers.
I hardly hear a difference between the EF86 and the ECC83 channel, probably because of the local feedback, so if you want to copy it, you could skip one of the two channels.
Because I couldn't find a schematic on the internet, I drew it up myself.
The amplifier sounds very clean and is very quiet (noise/hiss wise). There's local feedback in the first stage of both channels (something you hardly ever see in tube amplifiers for instruments) and the power stage uses GNFB and a Philips AD9047 UL OPT which was intended for Hi-Fi amplifiers.
I hardly hear a difference between the EF86 and the ECC83 channel, probably because of the local feedback, so if you want to copy it, you could skip one of the two channels.
Because I couldn't find a schematic on the internet, I drew it up myself.
Attachments
+1 It will have "the fender sound" (scooped mids) from the tone stack but there's a reason that Leo sold lots of them. Whack in a single 12" with decent tone (&high efficiency) and you're done.