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Help identafying 2 Output Transoromers?

Help identifying 2 Output Transformers?

I have a set of transformers that came out of an amplifier I can't find any information on and I have really given an effort.The amp had 2 6AQ5's.

The outputs are very small. There are numbers on them that read:

145A9887-1
REV-1
9495245

They have four wires

One reads:

Black, Blue, Red, Green
The black and green wires read 1 ohm
The blue and red wires read 530K

The second reads:

Black, Blue, Red, Green
The black and green wires read 1 ohm
The blue and red wires read 518K

They seem to look like they are probably good. The readings are very close.

Anyone have any idea what these are and/or know of a schematic?

Thanks in advance.
 
Last edited:

67marshall

Member
2016-03-16 6:34 pm
OK. I don't know how to go about that. Guess It's time to do some studding. Generally I make guitar amplifiers with new components knowing what I'm dealing with for the situation. This is definitely different for me. Do you happen to have an idea of what the OT's are from the information I gave or know of a way to look? There must be information somewhere.....
 
I have a set of transformers that came out of an amplifier I can't find any information on and I have really given an effort.The amp had 2 6AQ5's.

The blue and red wires read 530K

The blue and red wires read 518K

Thanks in advance.

Don't take resistance measurements with your fingers touching the wires/leads because your body's resistance will affect the reading.
Try measuring between red and blue again but without touching anything. With those 2 readings you got, sounds like both transformers are "open", unless you meant to write down 530 ohms and 518 ohms.

If all the windings are good, you have two single ended output transformers; they probably came out of a console stereo from the 1960s. Most of these has small (5 watts) stereo amps in them that were "single ended" with a 6V6, EL84 or as in your case, 6AQ5.
You can make a "CHAMP" style amp with them for guitar.

If you want to know what the impedance of the primary and secondary is, Watch this:

https://www.youtube.com/watch?v=Yzo3A-NywSs

The fun starts at 17:46. This should answer all your questions.

Chances are that each of the transformers has a primary impedance of 5000-5500 ohms and a secondary of 4 ohms.
They will work good for a single 6V6.
Frequency response will be adequate for a guitar amp but lacking for Hi-Fi; probably 50-12,000Hz.
 
Last edited:

67marshall

Member
2016-03-16 6:34 pm
I do know not to touch things when taking readings. I guess I should give everyone a more clear idea of what I do and know how to do.

Lets see.... ahhhh.... I make a variety of guitar amplifiers that are all push pull. I have never made a single ended guitar amp. Just not my cup of tea.

I just joined the forum so I don't want to talk too much about myself for fear of looking like I'm trying to self promote. I'm not here about guitar amp stuff. I'm here for odds and ends having to do with home stereo things.

Yes, the OT's did come from a stereo and it has a printed circuit board. I bet 1960's is spot on but I can't find on identifying thing on it.

I'll definitely watch the video you posted, thank you.

However, I really was hoping someone would see the numbers on the OT's and the readings and someone would go,

"Oh that's a (just for the sake of naming a name for example) Sanecore "whaterever", the code on it means 10 = October 57 = 1957, P = the series So you can find a schematic if you go look at this PDF"

I'll go watch the video now.