If given a supply of 450V plate and 400V grid (possible for TAD 6V6-STR and JJ 6V6S), what kind of output power am I looking at before OT loss? I was thinking about 50Watts, but I might be off..
Why would you opt for the complication of a quad of 6V6 rather than a pair of something more robust like 6550? Not carping, just asking, keeping in mind the KISS principle.
Valid question. I would implement different bias level on each pair. One pair would be biased cold, and the other pair would be biased hot. The hot pair would have a voltage divider to reduce its input gain.
It's something used by the mark series amplifiers from mesa boogie - simulclass is what they call it.
Shouldn't you have a special OPT for that?
The class A pair running at a higher impedance to keep then from melting and the class B pair at a lower impedance to deliver the higher output power?
I'm not sure but i think i saw a schematic like that with the two pairs on different taps on the OPT.
The class A pair running at a higher impedance to keep then from melting and the class B pair at a lower impedance to deliver the higher output power?
I'm not sure but i think i saw a schematic like that with the two pairs on different taps on the OPT.
Specs. for JJ6V6S link:https://www.tubesandmore.com/sites/default/files/associated_files/t-6v6-s-jj_specificationsheet.pdf
I don't know if I would put that much on or not. 500v?! Even 450v seems a bit of a stretch. Special OPT point is valid. Two different operating points usually means different pri. OT impedance. You could always have two OPTs into two speakers. At those voltages, 6L6s do sound like a better choice.
I don't know if I would put that much on or not. 500v?! Even 450v seems a bit of a stretch. Special OPT point is valid. Two different operating points usually means different pri. OT impedance. You could always have two OPTs into two speakers. At those voltages, 6L6s do sound like a better choice.
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thanks for the link, no wonder that when i ordered a quad of those, they looked more like 6L6GC's.....and so i used them in a 6L6GC circuit...
this is the 6V6 that i remembered....
http://frank.pocnet.net/sheets/049/6/6V6GTA.pdf
Different taps would not be needed for this application as the in balance sounds good for guitar.
Just originally wanted to know how much power 6v6 could provide given 450v plate and 400 grid ab/pp. I figured 50 watts would make sense, but I might be off.
Just originally wanted to know how much power 6v6 could provide given 450v plate and 400 grid ab/pp. I figured 50 watts would make sense, but I might be off.
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Someone asked for the estimated output power...
Ra-a=10k for 1 pair, 5k for 2 pairs:
Ra-a=10k for 1 pair, 5k for 2 pairs:
An externally hosted image should be here but it was not working when we last tested it.
The data sheet for JJ 6V6S gives 14 watts as max even for 500 plate and 450v screen. These are the design max. values. So it looks like 28 Watts for a pair. The above 31 w. is possible, but why would you push the tubes that hard with such small amount of extra power? It only gives you .4db extra volume, not really even enough to hear a difference.
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I ran a quad of vintage 6V6G (The old "coke" Bottle ST shape) into a 50W Marshall Output Tranny (Raa 3K4) with a B+ of 345V. I measured 27 Watts RMS continuous sine wave at just below the onset of clipping.
That Output tranny is a bit low on Raa. Raa of 4K3 is common and would have been a better option (or 5K). Having said that, those are 27 drop dead gorgeous watts. The output stage was a London Power "Standard" inspired thing with each of the 2 6V6 pairs switchable from Triode to Pentode mode and from Cathode to Fixed bias. It also had Powerscaling.
27W was Pentode Mode, Fixed Bias on both pairs.
Not a fan of designing for special, single supplier tubes. If it is a 6V6 amp it should be OK to put any 6V6 in it.
Cheers,
Ian
That Output tranny is a bit low on Raa. Raa of 4K3 is common and would have been a better option (or 5K). Having said that, those are 27 drop dead gorgeous watts. The output stage was a London Power "Standard" inspired thing with each of the 2 6V6 pairs switchable from Triode to Pentode mode and from Cathode to Fixed bias. It also had Powerscaling.
27W was Pentode Mode, Fixed Bias on both pairs.
Not a fan of designing for special, single supplier tubes. If it is a 6V6 amp it should be OK to put any 6V6 in it.
Cheers,
Ian
the octal JJ's i purchased on a local online store seemed to be holding up well, i have used over 2 dozen of EL34's....no issues so far...no one came back to me with complaints....😎
like i said, the quad JJ6V6 i got looked more like 6L6GC's so that i used them in a 6L6GC amp instead..
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