HOLLYTRAN vintagepower amp help

[Johnblue]

I have had this cool old rack mounted 5881 power amp  sitting for too long. I can’t find any information on the transformer company

“T.E. Transformer Engineers” “Hollytran” out of Pasadena CA

Any catalogs or anything would help.

It’s a huge balanced input transformer into a lone  12AY7 feeding PP 5881s

The input transformers are the most interesting part, but the stickers had been painted over and I only can decipher

60,000 - ????

Could be theater broadcast or studio?

I don’t know... but the HI-FI guys are confused haha.

Have you guys ever seen any amps in this type of configuration?

 

[Johnblue]

@emrr you seem to have run into a bunch of it, in another post you mentioned RCA used Hollytran in a lot of old equipment. Do you have any documentation on any of it? These traffos are Big UTC HA LS sized suckers.

 

[scott2000]

Could always try to draw out the circuit to get a good idea of what's going on..

 

[emrr]

I might have some data, bug me if you don’t hear anything soon.  Very cool amp.  Looks like it’s designed for and mounted on a Langevin or Cinema rack frame.  RCA Photophone used Hollytran in the late 40’s. 

 

[emrr]

Hard to say.  The circuits I found are different amps.  Many if not most of their transformers spec 20-20K +/-0.5dB.  It's top quality stuff and worth getting up and running.  Easy enough to put tones through iron and get ratios, good idea of values from resistances.  Could be 600Ω out.  Almost definitely 600Ω in, but could be a 20-30K bridging transformer.

The design would match Western Electric, Langevin, Cinema, or GE mounting, suggesting a Hollywood studio custom order to retrofit an existing rack installation. 

Someone forgot to put shock mounts under those mounting screws, I see the amp chassis are bent from tightening down. 

I've got several RCA Photophone modules that are line amps from remote truck designs, which are 600/20K input transformer to push-pull 6V6 to 600/150.  I've had a BA-11A variant that's Photophone branded and had a Hollytran input transformer with the same number as the typical BA-11A UTC.  I've also got a BA-1A type output that's a Hollytran version. 

They also made input transformers for both terminated and non-terminated conditions.  Amertran is the only other company i can think of that did so.