I was using DC on the heaters from my bench supply. Shouldn't hum. If I were to use AC, then your solution is very welcome and I'd do that.
I prefer not to use bypass caps - I used filament bias with the DHTs I used to build with like 26 and 4P1L. If I had to (like with the 300b) I would always use a proper polypropylene cap, and not a metalised one, certainly not an electrolytic. Thanks again - you are always very helpful!
I prefer not to use bypass caps - I used filament bias with the DHTs I used to build with like 26 and 4P1L. If I had to (like with the 300b) I would always use a proper polypropylene cap, and not a metalised one, certainly not an electrolytic. Thanks again - you are always very helpful!
You can see how good are results with 6P15P triode strapped in my thread from 2009.
Wavebourn Tower-III High-end hybrid amp
Wavebourn Tower-III High-end hybrid amp
Hello Anatoly - if I have EL84 already, is it worth getting some 6P15P as well? Any improvement in sound quality?
Here you have triode curves for E80L. But its a different breed than octal. Much cleaner sounding tube.
I don't know, EL84 is already pretty decent. May be you won't hear the difference.
My shortlist of triode drivers for my 300b SE is now looking like:
EL84/SV83 mu 20
E80L mu 21
6973 mu ?
6197 mu 22
EF80 mu 40
And in octal:
6V6 mu 10
EL33 mu 20
I've listened to EL84 and PL33 now, both good. I have some 6P6S (6V6) to try next. I've ordered some 6197. I think I tried EF80, can't remember. 6973 and E80L will be more expensive but my curiosity may well lead me to buy pairs of each.
There are plenty more I can try. I have 6S4A for instance, a triode which I have in a Leak Stereo 20 PPP mod with ECC40 driver. I also have ECC99, 6N30P, E80CC, 6SN7, 2C22 though I wasn't really seduced by any of those, not compared to EL84 or PL33. The 2C22 was good but I don't really want to use top caps and I'd like at least 15mA current for a 300b driver. I'm leaving out 4P1L, 2P29L, 46, 10Y which I've used extensively, since this is a deliberate experiment in indirectly heated tubes. I could go further into octals like KT61 and 6P25/26 but doubt if they would be better than my PL33. So it's back to the shortlist above.
EL84/SV83 mu 20
E80L mu 21
6973 mu ?
6197 mu 22
EF80 mu 40
And in octal:
6V6 mu 10
EL33 mu 20
I've listened to EL84 and PL33 now, both good. I have some 6P6S (6V6) to try next. I've ordered some 6197. I think I tried EF80, can't remember. 6973 and E80L will be more expensive but my curiosity may well lead me to buy pairs of each.
There are plenty more I can try. I have 6S4A for instance, a triode which I have in a Leak Stereo 20 PPP mod with ECC40 driver. I also have ECC99, 6N30P, E80CC, 6SN7, 2C22 though I wasn't really seduced by any of those, not compared to EL84 or PL33. The 2C22 was good but I don't really want to use top caps and I'd like at least 15mA current for a 300b driver. I'm leaving out 4P1L, 2P29L, 46, 10Y which I've used extensively, since this is a deliberate experiment in indirectly heated tubes. I could go further into octals like KT61 and 6P25/26 but doubt if they would be better than my PL33. So it's back to the shortlist above.
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