Altec Transformer?

[Crash]

I have stumbled upon an old Altec 1566A mic pre that is missing the 4722 transformer. My question is, where can a guy find one of these transformers and are these tranny animals interchangable? I have a 1588A tranny but I don't want to to fry the pre-amp without getting some clarification from those smarter than I before I proceed. Any help out there would be appreaciated.

Crash

 

[MikoKensington]

4722's are on ebay all the time. THey get kinda pricey. I don't think a 1588 would work. The 4722 secondary is grid impedence.

 

[NewYorkDave]

The 1588 isn't even a transformer; it's a little transistor preamp in an octal can.

If you can't find a 4722, any decent mic input transformer with a 50K secondary will do. If you can find one small enough to put inside an octal can, so much the better.

Let me know how you like your 1566A once it's up and running. I've had a broken one sitting in storage for years and I've wondered if getting it working would be a worthwhile project. The circuit doesn't look too good from a purely technical standpoint, but it could very well sound cool in some way, I suppose.

 

[Crash]

Thanks for the reply Miko. That is the kicker here. I have seen the 4722 sell on E-bay, as you say kinda pricey. I just hate to invest in a 4722 for a unit that may need a bunch of other work. If I could try a different tranny just to see if it passes signal then I might be more tempted to sink more money into the pre-amp. I have mountains of 15335A xformers at my disposal as well, plus a few others that I don't have the numbers on, as well as the 1588A, which says something on it about being a transistor mic pre? I just don't want to fry the preamp. Other than stuff sounding like crap, can I damage the preamp by trying different trannies, just to see if the preamp even works? I am not a tech guy by any means but more of an end user that produces and mixes. I know just enough to be dangerous here so speak slow and loud with your responses. Thanks again for your input.

Crash

 

[Crash]

Dave, you must have posted as I was responding to Miko. I will look at what other octal trannies I have and see if I can decipher enough to find one that may work. Mostly I have bridging transformers as well as a few line trannies lying about I believe. Thanks for your response as well. I hadn't expected to get help so fast.

Crash

 

[NewYorkDave]

You don't need a transformer to make sure it passes signal. You can insert a shorting strap between pins 5 and 7 on the input transformer socket and wire an unbalanced, low-level signal to pins 2 and 4 on the input terminal strip, as shown in the manual.

http://www.film-tech.com/manuals/ALTEC1566A.pdf

 

[Crash]

Sweet. I will give that a shot and see what happens. Thanks for the info. guys. I stumbled upon a bunch of Altec stuff that was about to be pitched, and since I am always looking for funky gear I snagged it. So far I am up to 2 436C comps., 1 1566A tube pre and a whacky little 2 input/i output 1589B mic pre. Both of the comps fire up and work but one sounds like hell. I will let you know how it goes with the 1566A pre. Thanks again all.

Crash

 

[wilebee]

I have 4 30 bucks each plus shipping Wil

Wilebee

 

[Crash]

You have 30 what? 4722's?

Crash

 

[wilebee]

Yes 4722 check you pm's Wil