Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: davidwpack on September 26, 2019, 10:04:11 am

Title: 8k
Post by: davidwpack on September 26, 2019, 10:04:11 am

Elllo! I seemed to have ordered an 8k Edcor a while back and have no memory of having done such. If I'm interpreting correctly, a pair of 6V6 would like my transformer very much? I just wanted to make sure before I had something planned. Thankssss

Title: Re: 8k
Post by: shooter on September 26, 2019, 10:10:02 am

yup, 8k is a good start.  It's easy to forget about Edcor since it's a 2mth lag time  :icon_biggrin:

Title: Re: 8k
Post by: sluckey on September 26, 2019, 10:21:28 am

EL84s would like that 8K also. Or, even 6L6s if the OT is heavy duty enough. Just relable the secondaries, ie, 4Ω becomes 2Ω, 8Ω becomes 4Ω, 16Ω becomes 8Ω, etc...

Title: Re: 8k
Post by: davidwpack on September 26, 2019, 10:50:23 am

Thanks guys! I'll keep that in mind. Yeah, it's. 50 watt. 4,8, and 16. I'm thinking British. Everything I've built is American flavor I think. Maybe 6V6 Plexi.. or the dual lite. I don't know. Maybe I'll get around to the Ampeg of Death with 6V6s.

Title: Re: 8k
Post by: PRR on September 26, 2019, 11:52:59 am

To use "all" of a 50W 8k suggests >500V B+ and large tubes.

In the 50W zone it is much more popular to use 4k so the ~~400V B+ suits 450V electrolytic caps.

Here's KT66 data. While this is for UL, pentode mode power will be about the same (THD is higher, damping is less). Any of the Large Bottles will do this if they can stand 525V on screens. KT66, EL34, 6550/KT88 OK; 6L6GC is dubious, though I am sure somebody does it.

Title: Re: 8k
Post by: davidwpack on September 26, 2019, 01:54:24 pm

Thanks for the info PRR! I'll probably do a lot of thinkin' for a couple weeks or so.