Help find a use for this huge transfo

Hi peeps!

I got this transformer a while back from a retired engineer and would like some help to figure how i could give it a second life.

I am just starting with tube circuits so i'm kinda clueless to find a suitable circuit.

The engineer did not remember the original usage. It was is some kind of "test jig box", with two octal sockets an input and multipin power connector.
(I can add pic later if interested).


Could not find any info on it on the web but it's made by Hammond.

Here's the specs on it:

Primary:
Impedance 7850 ohm
40 ma dc
8.5w max
60 cps (hertz)

Secondary:
Impedance 700 ohm
No dc


I calculted the ratio to be around 3.6:1.
I did not measure dc resistance and inductance yet because it is still in circuit.  I can measure later if it helps.


So anybody has ideas how i can use this thing? The 700 ohm output sounds like it could be good for line output but i don't know enough about tubes yet to know what tube output would be happy seeing 7850 ohm:700 ohm step down.

Idealy for me would be a tube DI line output, preamp line output.
(Although i would not get balancing because of the lack of center tap.).

Any help appreciated, thanks!
John

Seems like the photo did not come up.. i'm try again, sorry..

40mA primary for ~~7W at ~~8K sure sounds like a SE 6V6 "power" output.

Since 6V6 working conservatively won't be full 40mA or 8.5W, possibly a 6L6 not working too hard.

Adjusting the "700r" to 600r, the primary is near 6.7K. 6.7K times 40mA is 270V. Get a 300V supply. With cathode resistor and maybe a bit of ripple filter, you have a monster line-amp. +39dBm!! At 5%-10% THD. Well under 1% THD at normal line levels.

It is NOT clear that it has any high frequency response. It may be to power a servo motor around 60Hz, so anything over 100Hz is pointless. Basic winding technique usually goes higher, past 1KHz, but possibly not 20KHz.

Thanks Prr!

I think you might be up to something because i got some hockey puck sized servo motors in the batch from the same guy. I think he worked with aircraft. 

It was maybe used as a test jig for motors.

Glad to know it "could" be used for audio in theory. 

I don't know enough about tubes yet to try to design something around it but thanks for the pointers about the 6v6. 

I will try to experiment with it.

Thanks
John

search Garnet Herzog here at GroupDIY.    (active DI or Overdrive unit, pad output)

Thanks Cj!

Wasn't familiar with the herzog, sounds like a cool idea!