Hi all,
I would like to make a Marshall JTM45 clone, and my costs come off to roughly $300, including the tubes and undrilled chassis but I have a major problem: the transformers for the JTM45 cost $200-$300. My question would be, does anybody know/have access to information on how to make such transformers (power, output, choke), preferably specifically Marshall. I mean hand winding, start to finish. Would that save me any money (I have plenty of time and wire on my hands but I'm trying to save money) and would it be safe/efficient, given I would keep all safety precautions, of course.
I have not found an answer to this specific question on the forum, nor anywhere else on the internet, but if such a thread does exist, please send me a link and I will delete this one.
Thank you for your time,
Sincerely,
Tobias
I would like to make a Marshall JTM45 clone, and my costs come off to roughly $300, including the tubes and undrilled chassis but I have a major problem: the transformers for the JTM45 cost $200-$300. My question would be, does anybody know/have access to information on how to make such transformers (power, output, choke), preferably specifically Marshall. I mean hand winding, start to finish. Would that save me any money (I have plenty of time and wire on my hands but I'm trying to save money) and would it be safe/efficient, given I would keep all safety precautions, of course.
I have not found an answer to this specific question on the forum, nor anywhere else on the internet, but if such a thread does exist, please send me a link and I will delete this one.
Thank you for your time,
Sincerely,
Tobias
It can be hand wound of course, but, do you have experience winding transformers?
Transformers are not rocket science, even less Magic, but these ones carry an insane price tag just because "Clapton used them" , go figure.
I *think* I have that data stashed somewhere, let me try to find it.
Musical Instruments threads tend to get buried in the huge DIYAudio traffic, so PM me in 4 or 5 days , I might not see your question here.
I know very good transformers are being made in Poland, so I guess you have access to good wire and specially good iron.
Handwinding is fine, just sloooowwwwww
Transformers are not rocket science, even less Magic, but these ones carry an insane price tag just because "Clapton used them" , go figure.
I *think* I have that data stashed somewhere, let me try to find it.
Musical Instruments threads tend to get buried in the huge DIYAudio traffic, so PM me in 4 or 5 days , I might not see your question here.
I know very good transformers are being made in Poland, so I guess you have access to good wire and specially good iron.
Handwinding is fine, just sloooowwwwww
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Yes sir, I have the access to materials and plenty of time to work with, I only lack the knowledge and the instructioms to do it start-to-finish. I don't even know what parameters these transformers would need to be. I don't have much experience winding these things so some general information would be nice as well.
Thank you,
TF
Thank you,
TF
Indeed.Oh, I see the preconditions couldn't be better
But this isn't rocket science. The Radio Designer's Handbook is available on-line these days, making Chapter 5 (IIRC) the first place to go.
The second is use your favourite search engine as there dozens of "how to" websites, many of high quality (e.g. in six seconds I found Practical transformer winding ) Rumour on talkbass suggests that there were some in Polish, too
Careful searching will show that the usual sites (here, 18Watt, talkbass.com, guitargear.net.au,etc etc) already have several threads on transformer building.
Two key things to remember: you need to count your turns. And a single shorted turn will ruin your transformer - with voltages in the kV range that doesn't take much insulation damage.
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Oh, I see the preconditions couldn't be better
Best regards!
Hey, you gotta start SOMEWHERE
What else would you expect from a 17 y/o?
Broke, inexperienced with an abundance of time is just the way we are.
Cheers,
TF
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Yes, you nailed it!
I started winding my own transformers at about 14 years by unwinding old ones from radios and TV sets and re-using the wire, the bobbins and the lams. I've read many books before that told me the how-to. Anyway and as said before, even OT's aren't rocket science, but appear to bear somewhat mythical. Be prepared that your first efforts might not suffice you!
Best regards!
I started winding my own transformers at about 14 years by unwinding old ones from radios and TV sets and re-using the wire, the bobbins and the lams. I've read many books before that told me the how-to. Anyway and as said before, even OT's aren't rocket science, but appear to bear somewhat mythical. Be prepared that your first efforts might not suffice you!
Best regards!
Ok, the other place you should be looking is "public address line speaker" transformers. They were (and still are) used to allow public address amplifiers to be standardised with the amplifier putting out a certain wattage at a nominal, standarised voltage (here in the west either on a 70V or 100V). You then used step-down transformers with multiple taps to select how many watts you want at any location - from 0.25W (stairwell) up to 40W (big hall).
While your local voltage may not be 70V or 100V I can't imagine that you don't have a similar technology.
A while back, some clever people discovered that some even cleverer people worked out that you could wind a PP (or PP UL) transformer and also sell it as a line PA transformer.
For this part of the world, the go-to page is Cheap Output Transformers which lists common PA transfomers and how you can use them.
Given your situation you might try and work out if there's a scrap yard near you where these might end up when a building is demolished or refurbished, as they will go for less than their value in copper.
Now, even if you don't have the same sort of luck with your local transformers, at least they're a cheap source of parts for rewinding.
Good luck, keep reading, have fun and never forget that charged capacitors can have a lethal bite. Read RobRob's safety page. Particularly the bit about fatigue - it nearly killed me more than once.
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