Posted by Thermionic [ 70.173.99.212 ] on April 05, 2006 at 23:37:46:

In Reply to: Single Ended Amp for Electric Bass posted by DRCope on April 05, 2006 at 11:11:57:

Tube bass amps sound wonderful, IMO much better than any SS bass amp. BUT......... Bass takes *lots* of watts to reproduce, because a low frequency sinewave contains a great deal more energy than a high frequency sinewave of the same voltage (amplitude). I doubt even a pair of 2A3s in push pull would have the gusto for clean sound at modest playing levels. KT88s operating in ultralinear would probably be your best bet. You definitely wouldn't wanna use tube rectification, as it would be too "soft" and the power supply Z too high. You'd want a very stiff, well regulated power supply with no "give" in it whatsoever, and very low impedance as well, like a SS rectified, choke input supply with a few hundred microfarads of caps after the choke.

It would take some BIG output iron too. Because of the offset DC bias that causes SE output transformers to easily saturate on low bass notes, a SE output tranny that could pull off bass guitar duty would be a real monster. Push pull is definitely the ticket for bass guitar, even for low power.

OTOH, a SE 2A3 guitar amp would probably sound fantastic and be a relatively problem-free project to undertake, but would need a bear of a driver stage to feed the 2A3 if overdriven past the point of drawing grid current.

Thermionic

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