Can someone tell me what these x-formers might be used for?

[allbaldo]

I have some Hammond 842 transformers that I'd like to sell on eBay. On Hammond's website it says..

Application: P.P. Plates to line Primary: 5K/20K (6K/24K) Secondary: 125/500 (150/600)

More information can be found at: http://www.hammondmfg.com/560.htm#800

Can anyone give me an idea of what these could be used for? Mic pre's, console outputs, etc? I'm clueless with this stuff, and while I can list the specs above, I'd like to have an idea what they could be used for to help me find the right people to sell them to. They came from a McCurdy broadcast console. Perhaps they were part of the subgroups.. which is why I have 8 of them? Not sure. Any help would be greatly appreciated.

Stephen

[Brian]

125/600 would be a mic pre input if the 125 side is on the input xlr.

6k /24k is line input if the 6k is on the input. The 24k would make the output higher impedance.
http://www.tape.com/resource/impedance.html

[The Scum]

I think you're misreading the specs, Brian.

These are dial primary, dual secondary transformers. The primary can be wired in series for 24K or parallel for 5K. The secondary does 150 or 600, parallel or series, respectively.

Hammond put it fairly succinctly: they're for coupling the plates of a push-pull ( a.k.a."p.p.") tube amp to a 600-Ohm line.

You could wire one backwards (swap primary and secondary) to use it for a mic input...though it's a definite kludge.

[Brian]

Yep, I wasn't picking it up. Thanks for the correction.

[allbaldo]

Thanks for the responses guys! So I gather they have a very specific use, and probably don't have much use to anyone then?

Interesting they came from an 80's console with no tubes of any kind. Is there another use that makes sense in a not-tube setting?

I was hoping they could be used in a summing amp, or console outputs, or a mic pre, or something of that nature.

[sound for sandwiches]

couldn't they be used in a tube mic pre with push-pull topology in the final stage? like this altec:
http://www.waltzingbear.com/Schematics/ ... c_428B.htm