Was wondering if anyone had adventured into winding their own toroidal power transformer for an amp project. Looking around it appears that cores can be picked up relatively cheap compared to the cost of a manufactured transformer.
Silicon Steel Toroidal Cores - In Stock
Silicon Steel Toroidal Cores - In Stock
I'd like to look into this, though I understand it is very laborious to wind them. I don't mind repetitive laborious work though. Making them safe would perhaps be the paramount challenge.
A bit of a learning cure ahead just to get a transformer you think on the cheap.. I mean how many of these things are you ever going to need it really dosnt seem worth the effort. would be easier safer and quicker to modifiy existing secondry windings to your needs. Good luck
A core with a ready wound primary would save a lot of work in a step down transformer.
It would also be made in the same safe manner that a completed toroid is made.
I would not wind my own Mains Primary !
I have found a very few primary only toroids and they were all expensive !!!!
It would also be made in the same safe manner that a completed toroid is made.
I would not wind my own Mains Primary !
I have found a very few primary only toroids and they were all expensive !!!!
It does look like a lot of work to wind the primary on one of those - about 550 turns for 110V on the 233VA.
i guess andrew beat me to it i have just had a look at primary only toroids. approx twice the price as a transformer supplied with seondry windings... It would be much more cost effective to buy a ready made torroid and remove the secondry windings so you can wind your own.. have sent an email to airlink transformers i am still waiting for a reply..
Regards Mark
Regards Mark
Winding toroidals is a mess.Why not to buy second hand for cheap? I did that many times, never got any problem.
Here in the forum there are some comments I did about my toroidal transformers, some of them for power supply are working pretty fine, other for audio, are wrong and I will rewind some later.
I agree let the people who know exactly what they are doing and are set up already do the job.. If you want to wind your own fair play .. Would it be a way to improve sound . If not i miss the point
This the thread I was taking about:
http://www.diyaudio.com/forums/tubes-valves/205219-homebrew-toroidal-output-transformer.html
http://www.diyaudio.com/forums/tubes-valves/205219-homebrew-toroidal-output-transformer.html
that makes sense.
The time to pick a single secondaryless item off the shelf and post it out only saves a fiver.
But to pick 10 from the shelf gets closer to the real saving.
I suspect by the time you get to 100 off one would get a much closer to real cost.
And it shows up the rip off merchants that charge more for a secondaryless transformer than the full article.
Why would there be primary only transformers on the shelf?
Because winding the primary/ies and insulating it is a separate operation and an operation that never changes. All the 300VA primary only are identical. Make a 1000 off or 10000 off and stack them until the secondaries are required for item stocking.
The time to pick a single secondaryless item off the shelf and post it out only saves a fiver.
But to pick 10 from the shelf gets closer to the real saving.
I suspect by the time you get to 100 off one would get a much closer to real cost.
And it shows up the rip off merchants that charge more for a secondaryless transformer than the full article.
Why would there be primary only transformers on the shelf?
Because winding the primary/ies and insulating it is a separate operation and an operation that never changes. All the 300VA primary only are identical. Make a 1000 off or 10000 off and stack them until the secondaries are required for item stocking.
Hi folks,
"ASK Jan First" (Ask Jan First ® ; electron tubes and more) has a new service.
They can provide you with custom made toroids trafo's, and others to, at very competitive prices.
I ordered one with the following secundaries:
15,75-0-15,75V, 400mA
32-0-32V, 5000mA
9.7V, 1200mA
250V, 12mA
11V, 950mA
It was for a Johnson Amp and the original had a short.
After 2 weeks It reached my door for a price of less then 140€, shipping included.
Ask for a quote...
"ASK Jan First" (Ask Jan First ® ; electron tubes and more) has a new service.
They can provide you with custom made toroids trafo's, and others to, at very competitive prices.
I ordered one with the following secundaries:
15,75-0-15,75V, 400mA
32-0-32V, 5000mA
9.7V, 1200mA
250V, 12mA
11V, 950mA
It was for a Johnson Amp and the original had a short.
After 2 weeks It reached my door for a price of less then 140€, shipping included.
Ask for a quote...
Here the direct links:
Custom made transformers with standard cores:
Netztrafos Einzelstcke
And toroids according to your specs:
Einzelstcke Trafos
Custom made transformers with standard cores:
Netztrafos Einzelstcke
And toroids according to your specs:
Einzelstcke Trafos
Plitron makes some nice ones, at a reasonable price, expensive to ship however. I find getting them with more than one secondary coil is a problem, you get into custom designs.
Adding to the list .. Airlink transformers will give advice. Also provide a custom winding service.. UK based .
http://www.airlinktransformers.com/
http://www.airlinktransformers.com/
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Going back to the OP;
If it is for a one-off project (or even for 10 same amps) it's not worth the hassle to wind your own. You have to buy the cores, the wire, the insulation foil and so on.
Then you have to calculate the number of turns and find the correct toroid.
Not forget; wind them with the trouble involved.
To blow up the whole idea of doing it for cheap:
Spend a small fortunes on golden rca plugs, special audio grade caps, teflon or silver wire and a custom engraved front and back panel. Not to forget the sides of the amp made of an exotic hardwood with 15 layers of laquer, sanded in between with as much sheets of sandpaper.
As power tubes ( if a tube amp is build) the best power tubes are used for a steep price.
The search for the best sounding preamp tubes lead you probably (because they say so) to NOS tubes that cost a fortune.
Pots are changed by stepattenuators with golden contacts and 1% resistors.
And if it's solid state; Expensive FETS with a pcb stuffed with a box full of transistors and or IC's.
All the later cost so much that saving 20 or even 50€ on a transformer is absurd.
You can also do it cheaper and build a common amp, be it sand or glass, and these transformers are available off the shelf.
If you're not in the field of winding transformers and especially toroids; I would suggest to try companies that will make them for you.
Anyway; I respect everybodies choice and it's allways up to the individual to decide.
And having finished you toroid and it works fine; it gives you a feeling of "It's alive! It's alive!"
If it is for a one-off project (or even for 10 same amps) it's not worth the hassle to wind your own. You have to buy the cores, the wire, the insulation foil and so on.
Then you have to calculate the number of turns and find the correct toroid.
Not forget; wind them with the trouble involved.
To blow up the whole idea of doing it for cheap:
Spend a small fortunes on golden rca plugs, special audio grade caps, teflon or silver wire and a custom engraved front and back panel. Not to forget the sides of the amp made of an exotic hardwood with 15 layers of laquer, sanded in between with as much sheets of sandpaper.
As power tubes ( if a tube amp is build) the best power tubes are used for a steep price.
The search for the best sounding preamp tubes lead you probably (because they say so) to NOS tubes that cost a fortune.
Pots are changed by stepattenuators with golden contacts and 1% resistors.
And if it's solid state; Expensive FETS with a pcb stuffed with a box full of transistors and or IC's.
All the later cost so much that saving 20 or even 50€ on a transformer is absurd.
You can also do it cheaper and build a common amp, be it sand or glass, and these transformers are available off the shelf.
If you're not in the field of winding transformers and especially toroids; I would suggest to try companies that will make them for you.
Anyway; I respect everybodies choice and it's allways up to the individual to decide.
And having finished you toroid and it works fine; it gives you a feeling of "It's alive! It's alive!"
if weigth is of no concern old variacs are excellent toroids and can sometimes be found cheap on ebay. In europ they have a 50Hz 260V single winding, so running them on 230V keeps them cool and quiet. Just make sure there are no overload signs on them (easy to see if some windings are daker than others). First clean off the carbon depost, then paint the whole thing with airdrying transformer paint. Isolate the primary properly, put electrostatic shield overlapping and over at least the full primary circumference without making any shorts (for better hf-shielding you may want to partition the schield and/or make multiple schields), wind the shield tape to halfway and then back a few turns so you can solder the shield connection (without burning the isolation), finish the remaining half, isolate again and now wind your secundaries (make sure to spread out each of the secundaries over the full circumference of the primary below).
Very high quality DIY toroidial transformers can be made that way.
Very high quality DIY toroidial transformers can be made that way.
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Antek has great prices and a great selection. I wish I'd found them before I ordered from Plitron.
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