Hello-
I just built a very nice 6V6 push pull amp. Basically, I took 2 of Tubelab's Simple SE boards and made them into a PP amp with a balanced input.
http://www.diyaudio.com/forums/tubelab/171340-dual-simple-ses-push-pull-w-differential-input.html
Sounds very very nice. After building it, and running it with both EL34 and 6V6 tubes, I have some questions.
Observations:
With EL34 tubes in UL:
Sound extremely deep. Highs are very shimmery and detailed. Way too much power though for my 98db speakers. DYNAMIC as hell.
With EL34 in Triode
Definitely less power. Seems like I lost a whole lot of high frequency detail. Sounds a little dull to me.
Switched to 6V6
in UL: Dynamic. Detailed. Very nice
in triode: Very similar to UL actually. Details in music are slightly receded though. But very nice also.
Questions:
1) With EL34's switching between UL and Triode, the effect is DRAMATIC. But with the 6V6's the effect is extremely subtle. Why are the two modes so pronounced with one tube, but so subtle with the other?
2) With the 6V6's, I put a scope on the output, and ran a 200Hz sine wave through it. In UL, and Triode, I was able to get about 4V sine wave, before the sine wave visibly and audibly began to distort. The 4V distortion point was the same in UL and triode. Why is that? Shouldn't I be able to get more power in UL (ie higher Vpeak w/o distortion)? I was getting able to go about 7V max w higher distortion with either mode. My OPT's are 25W, so I do not believe it is the transformers distorting.
3) Am I the only maniac who seems to prefer the UL to triode?
I just built a very nice 6V6 push pull amp. Basically, I took 2 of Tubelab's Simple SE boards and made them into a PP amp with a balanced input.
http://www.diyaudio.com/forums/tubelab/171340-dual-simple-ses-push-pull-w-differential-input.html
Sounds very very nice. After building it, and running it with both EL34 and 6V6 tubes, I have some questions.
Observations:
With EL34 tubes in UL:
Sound extremely deep. Highs are very shimmery and detailed. Way too much power though for my 98db speakers. DYNAMIC as hell.
With EL34 in Triode
Definitely less power. Seems like I lost a whole lot of high frequency detail. Sounds a little dull to me.
Switched to 6V6
in UL: Dynamic. Detailed. Very nice
in triode: Very similar to UL actually. Details in music are slightly receded though. But very nice also.
Questions:
1) With EL34's switching between UL and Triode, the effect is DRAMATIC. But with the 6V6's the effect is extremely subtle. Why are the two modes so pronounced with one tube, but so subtle with the other?
2) With the 6V6's, I put a scope on the output, and ran a 200Hz sine wave through it. In UL, and Triode, I was able to get about 4V sine wave, before the sine wave visibly and audibly began to distort. The 4V distortion point was the same in UL and triode. Why is that? Shouldn't I be able to get more power in UL (ie higher Vpeak w/o distortion)? I was getting able to go about 7V max w higher distortion with either mode. My OPT's are 25W, so I do not believe it is the transformers distorting.
3) Am I the only maniac who seems to prefer the UL to triode?
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Basically with the 6V6's, I was playing a sine wave, and at the ouptuts measured a 4V sine wave in triode mode. Then I flipped the switch to UL. The output wave from the speaker terminals is still 4V, in either mode. So in that sense, they are automatically already level matched. Thats also of one of my questions. I was expecting to see a jump in voltage at the outputs when I switched modes.
I did not make measurements with the EL34's.
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