Hello there.....late to the 6V6 knowledge and design party.
I'm ashamed to say in my 64yrs (50yrs playing), never played any of the alleged iconic 6V6 powered amps.
It wasn't until the past 3yrs I was ever curious about them. I'm on my 4th and 5th amps powered by 6V6 (Matchless LC 20W & Mesa Cal Tweed 4:40). I wouldn't call either any of these iconic. I recently tried a 1980 Fender Deluxe Reverb first time ever. I like it also, but wish it had more power. I do believe that there is a sum of other things that determine an output sections perceived "tone" (if you will), output tube type, and how it's supported in a circuit are just a couple of things in the total sum of factors.
I've really come to like the Matchless and Mesa. I hear a difference in these 6V6 powered units that are distinctly different from other popular valves. I can also hear some similarities as well. I've given myself a lot of time in use to determine how much of what I hear is simply imagined rather than real. The Matchless is Cathode biased without any negative feed back (none I'm aware of). The Mesa has 5 different output classes selectable on a rotary sw.
Sorry....I know there is a lot of context I'm leaving our here. I simply don't know a lot about what I'm asking and hoping someone will at least point me to where I need to go for information.
Sorry guys.....I may have too many gaps in my technical knowledge in order to ask intelligent questions on this subject. And if you think that's the case making it too diffcult to give me an explanation no worries. I'll just keep digging and reading and eventually come to better conclusions, if I'm too ignorant to benefit from the great knowledge here.
6V6 tonal character.
Moderators: pompeiisneaks, Colossal
Re: 6V6 tonal character.
IMHO the cathode biasing and a feedback free power stage are keys for magical tone.
Fixed biasing will give you more headroom and output with a different feel, but awe inspiring tone also. With an OT with the right Z for the plate voltage, and a good speaker the amp will be a life-long companion.
You mentioned volume. A more efficient speaker will give you a volume increase.
Oh, also use NOS tubes. None of those foreign things posing as a 6V6.
I like RCA, Sylvania, and Westinghouse labeled blackplate 6V6GT's.
Many will disagree.
Fixed biasing will give you more headroom and output with a different feel, but awe inspiring tone also. With an OT with the right Z for the plate voltage, and a good speaker the amp will be a life-long companion.
You mentioned volume. A more efficient speaker will give you a volume increase.
Oh, also use NOS tubes. None of those foreign things posing as a 6V6.
I like RCA, Sylvania, and Westinghouse labeled blackplate 6V6GT's.
Many will disagree.
Last edited by TUBEDUDE on Fri Feb 24, 2023 9:47 pm, edited 1 time in total.
Tube junkie that aspires to become a tri-state bidirectional buss driver.
Re: 6V6 tonal character.
I'm not quite sure what you're asking. 
To my ears, 6V6s sound like mini-6L6s. I quite like them, and use them in all my more recent 20-ish watt builds (and once even in a 4x 30-ish watt design).
They are typically run at voltages in excess of what the old data sheets recommend.
They are similar in characteristics to the EL84, but with a bit less voltage gain and slightly different bias voltage requirement. They are more robust physically than the EL84, and typically don't require retainers to keep them from falling out of their sockets.
To my ears, 6V6s sound like mini-6L6s. I quite like them, and use them in all my more recent 20-ish watt builds (and once even in a 4x 30-ish watt design).
They are typically run at voltages in excess of what the old data sheets recommend.
They are similar in characteristics to the EL84, but with a bit less voltage gain and slightly different bias voltage requirement. They are more robust physically than the EL84, and typically don't require retainers to keep them from falling out of their sockets.
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FUCHSAUDIO
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Re: 6V6 tonal character.
I would take a 6V6 over an EL-84 in heartbeat. They clip smoother and more musically and are more robust. I firmly believe EL-84's simply don't have enough glass to dissipate all the heat being produced by the routine misuse guitar amp makers put them through. Even in old Scott stereo amps, they are often blackened from electron bombardment. I converted a bunch of Blues Juniors to 6V6's and they sound warmer and fuller and you can beat the shit out of them and the tubes last, since it's 300-ish B+...mhuss wrote: ↑Fri Feb 24, 2023 9:35 pm I'm not quite sure what you're asking.
To my ears, 6V6s sound like mini-6L6s. I quite like them, and use them in all my more recent 20-ish watt builds (and once even in a 4x 30-ish watt design).
They are typically run at voltages in excess of what the old data sheets recommend.
They are similar in characteristics to the EL84, but with a bit less voltage gain and slightly different bias voltage requirement. They are more robust physically than the EL84, and typically don't require retainers to keep them from falling out of their sockets.
BTW: The "sound" of a 6V6 is often dependent on the maker. JJ 6V6's are basically 6L6 style construction in a small bottle and sound it. The new Psvane made TAD red base 6V6's are terrific and sound awesome and hold up well in the 400ish B+ range.
Proud holder of US Patent # 7336165.
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dorrisant
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Re: 6V6 tonal character.
I totally agree with what Andy said. I try not to use EL84s unless I have to. I started building JCM800 style amps with 6V6s and realized I'm not the only one who loves the clean and distortion characteristics of them. Then marshall started coming out with their mini amps loaded with them. I regularly use JJ 6V6S in Dumble clones set up as 19 watt tubes. These amps are a lot louder than you'd expect for 6V6s and seem to last extremely long as compared to the same circuit with EL84s. Those Deluxe Reverbs (blackface) that regularly sell for $3000 - $4000 should attest to the tone that can be had with them.
"Education is what you're left with after you have forgotten what you have learned" - Enzo
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dorrisant
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Re: 6V6 tonal character.
I'm cool with it. Works just fine with a cut control though.
"Education is what you're left with after you have forgotten what you have learned" - Enzo
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FUCHSAUDIO
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Re: 6V6 tonal character.
Lots of factors could cause this, but no NFB shouldn't be the sole cause of this issue. A cathode biased no NFB pair or quad of 6V6's can be a seriously fun amp to play...
Proud holder of US Patent # 7336165.
Re: 6V6 tonal character.
There is no speaker control, amp in current mode and hi output impedance, speaker must be selected very well to handle this combination, but for most cabs not good which limiting the amp purpose. So only problems in short 
Voxish cut is working ok, but cutting too much maybe...
Voxish cut is working ok, but cutting too much maybe...
Re: 6V6 tonal character.
Thank you to all for the info. It does help.
Just aquired another. 40W Laurel Canyon.
Just aquired another. 40W Laurel Canyon.
Re: 6V6 tonal character.
In any amp, the designer will shape the desired response, regardless of feedback or class of operation.
Tube junkie that aspires to become a tri-state bidirectional buss driver.
Re: 6V6 tonal character.
My experience is single ended amps with no feedback has too much treble because of high output tube impedance.
This can be remedied with a bit of feedback to make the output more linear. I think that is why most Champ-style amps has feedback.
Re: 6V6 tonal character.
Feedback is not the only remedy. In fact it may be the worst depending on your tonal target. The feedback changes dynamics, and the attendant smearing from phase shifted feedback kills the 3D magic of clean tones. If your tonal target is in the hard rock vein, then you want feedback, say to emulate a cranked Marshall, Hiwatt or whatever. Most of my builds are without it, even the higher powered KT-88 class AB amps.
Tube junkie that aspires to become a tri-state bidirectional buss driver.
Re: 6V6 tonal character.
What would you propose instead, a late treble cut? Or a Zobel filter?TUBEDUDE wrote: ↑Wed Aug 30, 2023 2:03 pm Feedback is not the only remedy. In fact it may be the worst depending on your tonal target. The feedback changes dynamics, and the attendant smearing from phase shifted feedback kills the 3D magic of clean tones. If your tonal target is in the hard rock vein, then you want feedback, say to emulate a cranked Marshall, Hiwatt or whatever. Most of my builds are without it, even the higher powered KT-88 class AB amps.
I’m more into a complex, bluesy tone.