Hi folks!
Maybe this was asked before... I would like to wind my own output iron for a 2A3 class A amp. Let's say I would like to make a Tamura F-475 clone
Anyone has unwinded classic iron and posted the recipe?
I would like 5K plate to plate resistance and 8 Ohms speaker tap
20 / 20K Hz response @ 3.5 watts
I am reading Wolpert Audio Transformer Design Manual, but it is discouraging... as I would only want to make what I stated above.
Regards
Maybe this was asked before... I would like to wind my own output iron for a 2A3 class A amp. Let's say I would like to make a Tamura F-475 clone
Anyone has unwinded classic iron and posted the recipe?
I would like 5K plate to plate resistance and 8 Ohms speaker tap
20 / 20K Hz response @ 3.5 watts
I am reading Wolpert Audio Transformer Design Manual, but it is discouraging... as I would only want to make what I stated above.
Regards
Hi,
Designing OPT is an Art.
The 4th edition of the Radiotron Designer's Handbook has a good chapter on this subject. This is where I got my info from. A bit frustrating as it uses old units (gilberts, mils...).
Visit Peter Millet's website or look for the pdf version of this reference book online.
Good luck. Have fun 😉
Serge
Designing OPT is an Art.
The 4th edition of the Radiotron Designer's Handbook has a good chapter on this subject. This is where I got my info from. A bit frustrating as it uses old units (gilberts, mils...).
Visit Peter Millet's website or look for the pdf version of this reference book online.
Good luck. Have fun 😉
Serge
Audio Transformer Design Manual, Robert G. Wolpert may too help.(Edit: OOps, you already got it.)
Another problem is to find lamination you want to use in small quantities.
Another problem is to find lamination you want to use in small quantities.
Last edited:
what type of core do you have, pics would be nice, what is the thickness? 0.35mm is better than 0.5mm in general...
Hi pastito,
You have two choices:
1 - Learn how to design audio output transformer.
This may be a long process, I started in 2000 and I probably never acheive to learn.
2 - Copy an existing design, see attached
Yves.
You have two choices:
1 - Learn how to design audio output transformer.
This may be a long process, I started in 2000 and I probably never acheive to learn.
2 - Copy an existing design, see attached
Yves.
There are several winding diagrams, and a lot of theory, published on remarkable Turner Audio web site. As I'm writing this it is offline, hope it will come back soon.
http://www.turneraudio.com.au/output-trans-theory.htm
http://www.turneraudio.com.au/output-trans-theory.htm
Yes, I'm French !
There are very few words to translate, in doubt ask.
And all dimensions are metric, of course.
The size of the core and the associated coil former is EI96-40 that means EI laminations having the lenght of the "I" piece equal to 96mm and stacked to obtain 40mm height.
There are very few words to translate, in doubt ask.
And all dimensions are metric, of course.
The size of the core and the associated coil former is EI96-40 that means EI laminations having the lenght of the "I" piece equal to 96mm and stacked to obtain 40mm height.
Making a power transformer is easy but with a OPT you have to make make 1 part of the prim windig than a part of sec winding than back to the prim winding and so on
this is done to make the best responce between 20 HZ to 20000 HZ
this is very difficult to do
So i don't even begin to make one
Here in the netherlands we have a company that wil make on specs your transformers
It's also very dificult to order small amounts of materials for making an OPT
this is done to make the best responce between 20 HZ to 20000 HZ
this is very difficult to do
So i don't even begin to make one
Here in the netherlands we have a company that wil make on specs your transformers
It's also very dificult to order small amounts of materials for making an OPT
Here is my simple winding machine
An externally hosted image should be here but it was not working when we last tested it.
This is one case where hand winding on the kitchen table is better, when you switch wire diameter from layer to layer, you just guide it by hand.
Good lightn and reading glasses if needed, help a lot.
All it takes is time, but a long, boring, rainy weekend should be enough.
Now setting an automatic winder advance screws and gear for one wire diameter, then for another, and so on 10/20 times is VERY frustrating.
That's why many manufacturers "cheat" and wind in bulk, first one diameter in a lot of coils, then another.... and that's it.
Pastito: de qué casa de trafos estás hablando? 🙂
NL3PRC: LOVED your homemade winder 🙂 🙂
Only problem, your wife will kill you when she sees you destroyed her broom to make your machine 😉
Good lightn and reading glasses if needed, help a lot.
All it takes is time, but a long, boring, rainy weekend should be enough.
Now setting an automatic winder advance screws and gear for one wire diameter, then for another, and so on 10/20 times is VERY frustrating.
That's why many manufacturers "cheat" and wind in bulk, first one diameter in a lot of coils, then another.... and that's it.
Pastito: de qué casa de trafos estás hablando? 🙂
NL3PRC: LOVED your homemade winder 🙂 🙂
Only problem, your wife will kill you when she sees you destroyed her broom to make your machine 😉
Last edited:
Hi, I have some information about xformer design , you can send me a PM and we can to talk about it
Is there any advantage in using R-Cores? And where can one get the blanks (other than unwinding an existing one)? ( I am new at this, so please excuse it if it is a dumb question )
to make an OT that works is quite easy. ('materializing' a basic principle)
to make one with excellent parameters ('hi-end' sound, bandwidth, smooth response without unwanted by-products) is usually possible only after a long time of learning (all those initially invisible details), trying, testing (both listening and measuring, on a well known reference setup as well as 'the friend's rigs' etc.) There are so many tubes, core materials, shapes and sizes, winding approaches, wire and insulation details and mostly - so many subjective interpretations of sound aesthetics.. that it makes quite a big equation to solve.
but.. if there is passion and involvement, time and access to material, i'd say go for it. just don't be swallowed by 'shallow and suggestive esotericism'
to make one with excellent parameters ('hi-end' sound, bandwidth, smooth response without unwanted by-products) is usually possible only after a long time of learning (all those initially invisible details), trying, testing (both listening and measuring, on a well known reference setup as well as 'the friend's rigs' etc.) There are so many tubes, core materials, shapes and sizes, winding approaches, wire and insulation details and mostly - so many subjective interpretations of sound aesthetics.. that it makes quite a big equation to solve.
but.. if there is passion and involvement, time and access to material, i'd say go for it. just don't be swallowed by 'shallow and suggestive esotericism'
- Status
- Not open for further replies.