What to build with these transformers?

[gadget73]

Battradio was kind enough to link me to a pair of transformers for sale that I've been trying to mate for something like 4 years now. Its a Chicago BO-13. Specs from the 1958 catalog as follows:

10k primary
4/8/16 ohm secondary
screen grid taps (don't know the %)
20W
5881, 807 output tubes


Some other searching indicates this is supposed to be the same transformer used on a Heathkit W4M. Not 100% sure if this is accurate, but its the internet, so it must be true! If not, some data I found here on AK supports the idea they're pretty similar at least.

So the question now is what do I build around them? 10K seems high for a 6L6 family tube, but what the heck do I know. Is this my excuse to build that 1625/12SN7 amp?


All this assuming I end up with them. If the price ends up too dear, someone else can have them.

 

[kward]

Well I sure love my 1625 amp. If you did Dave's EFB for bias/screen supplies, you could probably swing a 10K output tranny. Wouldn't take advantage of the UL taps though, but I bet it would sound just as good if not better.

 

[battradio]

A PP pair of 10's or VT25's would be real nice

 

[gadget73]

6BQ5 P-P would fit in there. Maybe parallel 6K6 P-P, too.

6

I actually have a single one currently, and I did whack together a rather ugly 6BQ5 amp in the chassis it came on. SOunds quite good, which is kind of why I've been looking for a twin to it for about 4 years now. May not be the worst use for them.

Still though, all a big "if". I'd still have a single that needs a mate even if I got these

 

[Shadowdog]

Should work great with fixed bias 6V6 according to an old time amp builder on another forum.

Cathode Bias would work great for EL84/6BQ5.

 

[golana]

Williamson, and there are plenty updated versions.

http://www.bonavolta.ch/hobby/en/audio/807.htm

 

[Jcricket]

I have a schematic from Stromberg Carlson. 6F6 PP. Uses 10k iron. just an option.

I'll likely build it in the next few months myself.

 

[battradio]

If your adventurous 6HE5 are cheep , they are 6V6's with a 12 pin base , buy a couple sleeves of them to have a lifetime supply .

http://tubedata.tubes.se/sheets/049/6/6HE5.pdf