GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Melquiades Amplifier
In the Thread: Single-stage Melquiades vs. DHT amps

Post Subject: The 10Y...and bye bye NewtonPosted by cv on: 6/17/2009

Hello Romy,
I've only heard the 801 in class A2, but I can easily imagine that the 10Y or 801 with nickel output would offer the purest possible sound in the 1k-10k range, such that it is the S2's true voice you are hearing. It's something I'm going to pursue when I have time/funds...

Alas I do think that your existing amp platform (i.e. B+ voltages) is not optimal for 10Y; the DC coupling would be out etc and this may well swamp the differences between tubes.

Anyway, whilst you do have the urge to experiment, you really, really should try a tapped filter choke at the front for gain adjustment instead of the attenuator at the S2.

If it's not too much a departure from the subject of the thread, I'm a little surprised to see the back of the "Newton bias" scheme; does the 6E5p still retain its special qualities in this application with the more pedestrian bias arrangement here (IIRC the Newton scheme's primary benefits were at LF?), or might it now be worth experimenting with a filament-biased DHT at the front (and dropping some gain in the process...)? You might ask Dave if he knows of any 9-pin DHTs with mu of about 18 and Ri of about 1k... or have me send some old Limey ~~tubes~~ - begging your pardon, sire - valves to try...

I do appreciate that this amounts to untargeted experimentation and may be an intellectual exercise for the most part, but it would form a consistent continuation of the amp's development path.

Cheers
cv

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