Rerurn to Romy the Cat's Site
In the Forum: Melquiades Amplifier
In the Thread: The one-stage Melquiades.
Post Subject: Granularity and other thingsPosted by ml8 on: 4/23/2007
Sorry Romy, i can't tell you about life longevity of 6E5P in my amp 'cause i'm not using them there anymore 
For my speakers two-stage SE sounded much nicer, more balanced and clear with more volume. Well at least it was easy to predict, considering 88 dB sensitivity. Anyhow, that amp was re-assembled as two-stage with 6P1P in output.
But still, during my experiments in my STSE-amp I have found some interesting things.
First was that zero biasing that i've already mentinoned. It changes sound of different tubes in very different way -- with grid currents some are absolutely unlistenable, rest ones are more or less sounding the same, and only few -- sounds VERY different, but in much BETTER way. Better so far that i'm thinking 'bout whole amp with zero bias in all stages.
This few tubes was 6E5P, 6S45P (which i've found a little better for my single-stage amp that 6E5P) and... perfectly god-like sounding (output beam tetrode) 6P6S!!! Triode-connected, for sure. Absolutely the MOST clear sounding driver, and i believe there is something magical in it's sound cause i can't describe it with words -- it just THAT sound and thats it. Much more... should i say, inspiring? -- than anything else i've heared at driver stage.
Pity this way 6P6S has low amplification factor. I think i will use it with interstage transformer or adone choke to get more output, and then to drive another 6P6S in output stage... BTW, tube with close specs, 6F6P (output pentode) didn't sound even remotely as well as 6P6S; actually it sounds horrible in this mode.
And about that your findings -- very interesting.
You see, i'm always struggling to find sound without that damn granularity in it, but so far i did not succeeded. 
Only few of my amps (DHT with kenotron rectifier) were almost free of granularity, but still they all have other flaws and i took them apart for later projects. Still i don't know exactly WHY they was sounding so smooth -- is it DHT, or kenotron, or something else?..Rerurn to Romy the Cat's Site