Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: A13X on February 05, 2022, 01:00:35 pm

Title: Is a 3.5k OT ok for 6v6s?
Post by: A13X on February 05, 2022, 01:00:35 pm
Hello all, I’ve been lurking/learning from this forum for a while now.
I was hoping someone could help me with a problem I’m stuck on.

I have a kit amp designed around the bassman (25watts) that included a 3.5k 25 watt OT with 3 secondary taps.

Is it acceptable to go to JJ6V6S tubes with this OT?

Thanks so much everyone!
Title: Re: Is a 3.5k OT ok for 6v6s?
Post by: sluckey on February 05, 2022, 01:39:02 pm
Keep it simple. I would just leave the 6L6s in the amp. Adding 300mA load on the filament string is not going to hurt anything.
Title: Re: Is a 3.5k OT ok for 6v6s?
Post by: A13X on February 05, 2022, 03:54:57 pm
Keep it simple. I would just leave the 6L6s in the amp. Adding 300mA load on the filament string is not going to hurt anything.
Ok , thank you! The OT is rated for 3A. When I looked it up adding the tube would put me at 3.12A. If this isn’t a concern then I’ll keep them. I don’t know what the acceptable % over the rating I can safely go…
 I guess it would have been easier to ask that question first [facepalm]
Title: Re: Is a 3.5k OT ok for 6v6s?
Post by: A13X on February 05, 2022, 04:04:53 pm
Keep it simple.

I edited so it would be, my apologies
Title: Re: Is a 3.5k OT ok for 6v6s?
Post by: sluckey on February 05, 2022, 04:21:33 pm

Ok , thank you! The OT is rated for 3A. When I looked it up adding the tube would put me at 3.12A. If this isn’t a concern then I’ll keep them. I don’t know what the acceptable % over the rating I can safely go…
When you add the extra tube measure the filament voltage between pins 2 and 7 of one of the 6L6 sockets. What have you? I would not be concerned if it is still at least 6VAC.

Most new PTs will be putting out more than 6.3VAC. I would not be surprised if adding 1 more tube still yields more than 6.3VAC.