recycling old transformers for wind your own experiments?? and learnings..

Hello one and all,

Well I have set myself the task of trying to come to terms with truly understanding how audio transformers go together, and I was wondering - can I use older cheap and readily available transformers and use them as a source of parts (wire, mounts etc), to experiment with winding my own.

One of the reasons I have never tried to make my own is the initial cost, and so I thought maybe I could muck around by reusing older ones and pull them apart and rewinding them first (to experiment).

Is this a sensible approach?

Mac

Taking things apart and studying them is a great way to learn, particularly where mechanical is concerned.

Also  look up for posts about transfromers and read CJ's posts. He hacked quite a few of them.

Hey Sahib,
Yes i have read many of CJ's posts (usually not understanding them fully).

I guess I just wasnt sure if it was worth the effort to try to reuse materials like the wire or the lams used etc

dunno if its worth it.. but i tried this;


I made few transformers and amp to drive them.
and that was from old trafos(alltho i made some cores from razorblades and stuff)
atleast you learn something

mac said:

Hey Sahib,
Yes i have read many of CJ's posts (usually not understanding them fully).

I guess I just wasnt sure if it was worth the effort to try to reuse materials like the wire or the lams used etc

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It is always worth the effort to re-use materials. Not only it is environment friendly it also saves you quite a lot of money in the long run. For example I have not bought hook-up wires or screened signal wires for years. I have boxes of them removed from audio/broadcast equipment which were normally going to skip. In '97 I bought few hundred broken customer returns compact cameras. I have still been using the micro screws that came out of them. I have over 500 robot arms being used in education worldwide which have almost all of their screws re-cycled.

mac said:

Hello one and all,

Well I have set myself the task of trying to come to terms with truly understanding how audio transformers go together, and I was wondering - can I use older cheap and readily available transformers and use them as a source of parts (wire, mounts etc), to experiment with winding my own.

One of the reasons I have never tried to make my own is the initial cost, and so I thought maybe I could muck around by reusing older ones and pull them apart and rewinding them first (to experiment).

Is this a sensible approach?

Mac

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There's also some very good reference reading material that CJ posted in the META I believe - with footnotes for each volume.  Like you I've been interested in doing this at some point but I haven't made much headway.  There's certainly a stack of critical details in the construction craft to master along with the basic theory.

Reusing old materials and winding single value inductors is a good simple way to start - then try tapped inductors.

Hey guys, thanks for the tips - invaluable as always...

Mac

I've got a couple old power transformers set aside for just such a learning endeavor. Haven't gotten around to it yet.
RDH4 has a section on xformer design (of course! That book...  ), and I believe CJ posted a link to a PDF copy of "Audio Transformer Design Manual" by Robert G. Wolpert. I'll put it in the groupdiy gmail account when I get home or mac if you want to pm me your email address I'll send it on directly as well.

Would be great to have a copy of that manual.

sahib said:

Would be great to have a copy of that manual.

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ditto... I did pick up a copy of "Quick & Dirty" Transformer Design and Construction from Lindsay Publishing for like, 7 bucks... lots of good info in there to help build some custom tube PTs.

hey Andrew,
my email is in my signature thanks....

Mac

...do the lessons in interleaving, etc, apply to a toroid core?  I see a lot more salvageable (ethically and practically) toroids than EIs.  I've heard that the core usually needs to be larger, and DC needs to be avoided; has anyone messed around with audio toroids much?  Microphone inputs in particular?

Also-- appliance repair stores will let you carry away old microwaves and such.  Lots of heavy-gauge wire and sheet metal to be found in them, as well as machine screws and 15-amp power cords.  Microwaves also contain powerful magnets.  Some people have used them in domestic windmills....

appliance repair stores will let you carry away old microwaves and such

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funny you should mention this. I met a chap last week that has an entire "field" of old TV's, microwaves, VCR's and computers etc. He has offered for me to go and spend half a day stripping them down for their pcbs etc (an he offered for me to "fill a trailer" with what ever I want).

Mac

andrew_k said:

I believe CJ posted a link to a PDF copy of "Audio Transformer Design Manual" by Robert G. Wolpert. I'll put it in the groupdiy gmail account when I get home or mac if you want to pm me your email address I'll send it on directly as well.

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Any chance you'd be able to upload that the gmail account? Ive been checking the account like a school-boy waiting for Christmas.

Much appreciated!

gemini86 said:

Any chance you'd be able to upload that the gmail account? Ive been checking the account like a school-boy waiting for Christmas.

Much appreciated!

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Oh shoot, I completely forgot! I have uploaded it now to the gmail account, subject: Audio Transformer Design Manual - Robert G. Wolpert

andrew_k said:

Oh shoot, I completely forgot! I have uploaded it now to the gmail account, subject: Audio Transformer Design Manual - Robert G. Wolpert

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Well I was planning on studying for a dynamics test tomorrow... So much for that. Couldn't have waited one more day

Now I have something to do all weekend, thanks!

I have some huge chunks of iron sitting in an old Bell amplifier from the 50's. It wasn't worth fixing so I figured I'd keep it for parts just in case. I may slice one in half for gits and shiggles.