Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: 2ndserve on July 02, 2019, 10:50:38 am
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In the garage along with too much crap, I located a couple Chicago Transformer 8714 units. 4 leads each, I'm assuming they are SE OPT's...but what do I know. I was unable to locate these online or in any Chicago Transformer catalog, but did find hint that a WE output transformer with the same part number, same general size but in a different housing were used as 6V6 SE OPT's and that they used Chicago/Stancor for stuff. If so, it seems one would be perfect for the 6V6 driven 6G15 reverb build which I am seriously considering.
DC readings are around 200ohms and 800ohms on both. I get that I could test them to find out for sure, but if anyone here has knowledge I don't that would make that unnecessary...well, I wouldn't be mad about that.
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DC readings are around 200ohms and 800ohms on both.
Are you saying these two readings are for one transformer? And the other has identical readings? If so, then these are not output transformers. The secondary on a typical output transformer meant to drive a speaker is very low, often less than 1Ω.
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With DCR's that high, I'm thinking they might not be OT's.
Step up/down interstage transformers is my first guess.
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Sluckey: Yes, exactly. 200 and 800 individually. The site(s) I read about testing said dc resistances should be low but didn't state speaker impedance low.
So, were these were used instead of coupling caps between gain stages in some applications?
High impedance headphone amp material maybe? :)
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At this point I have no reason to think they are were used in any kind of audio circuit. Anything I say would be a wild ass guess. Let's see some pics. Do you have any idea where they came from? What kind of equipment? How did they come into your possession? etc, etc.
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Short answer, with 10 others in a milk crate.
Sheesh, what an awful pic!
Long answer, I have boatloads of tubes, tube gear, gathered from garage sales, auctions, etc over years. Was super into hi-fi and not much into guitar playing when I accumulated it all. That reality has flipped. I probably have 50+ P/P amps of some variety or another (console, PA, stereo) lying about as my Hi-Fi focus went SE'd. I figured I'd get to them someday. Tubes, transformers, speakers, turntables and parts of all sorts are my homes general decor to my wife's occasional consternation.
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Sheesh, what an awful pic!
yep. no help. I was hoping to be able to read the writin.
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I have a weird LED light over my computer, it and phone camera's do not get along. Forgot that until the pic.
Other than the Chicago Transformer label and the 8714 number etched into them they have no information to offer.