Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: toomanyslurpees on February 05, 2011, 09:48:08 am

Title: Tubes for YBA-IA, bass master II?
Post by: toomanyslurpees on February 05, 2011, 09:48:08 am

I just picked up this amp for a pretty good price yesterday, it hasn't been fired up in over ten years and I'll believe it considering the totally even layer of dust on all the knobs... I didn't bother taking the guy's offer on firing it up when I came to pick it up and I'm glad I didn't, when I got it home I realised on of the tubes was broken off the base so who knows what kind of sparks could have occurred. (I got it for cheap enough that putting some money into would still make it worth it)

So this amp is basically the same as the YBA-1 except it runs in the 90 watt range instead of 45, but it's using EL34s, that's driving an EL34 pretty hard right? Is there a brand that's going to stand up to this better? I've read about someone running 6550s in one, thought I would get thoughts from you guys here.

I think this is from the early 70s, going to do the caps and a grounded power cord and go from there. It had 'PM' tubes except for two phillips preamp tubes, anybody heard of this 'PM'?

Title: Re: Tubes for YBA-IA, bass master II?
Post by: Tiny_Daddy on February 05, 2011, 11:49:15 am

If you have the space use KT88.