Pultec Transformer/s - DIY

[dawsonaudio]

I've been wanting to do a point-to-point of the eqp-1a and meq5 for a while.  I've got all the parts for the eqp-1a minus the iron and inductor.  I'd like to try to wind some transformers and an inductor.  I've read a lot of info here about the different aspects of transformer design.  I haven't been able to find a step-by-step on how to to put one together.  I'd like to try it out, but not sure if it is something that is too difficult to perform without a lot of expensive tools.  I've got a meter that measures inductance, but no scope.  I do know I need wire, bobbin, core, insulation, tape, laquer....

I currently have a couple UTC  A-10's for the interstage transformer if I decide to buy off-the-shelf iron instead. 

Thanks for any advice here.

Nate

 

[dirtyhanfri]

I'm looking into build a winding machine with stepper motors and a micro controller to run the software like this one http://www.theprojectasylum.com/electronicsprojects/automaticcoilwinder/automaticcoilwinder.html

I don't think you'll need special tools, but a lot of supplies not so easy to get (core material and bobbins mainly) and a lot of hours reading, winding and unwinding, testing and such.

Looks like a hobby itself

 

[tubestation]

Hello,
It s not easy to find high Nickel Lamination in small  Quantity.
A Forummember, can t remember who ,  used this Core to wind a V 72 Clone Inputtransformer with good Results.
http://www.ebay.de/itm/230646735924?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

In the Meta You find a lot usefull Information about Inductors
http://groupdiy.com/index.php?topic=16761

And about Transformer winding
http://groupdiy.com/index.php?topic=467

In the Meta, You find also all Information to build and test the Pultec

http://groupdiy.com/index.php?topic=37850

There You find great Information to read and learn for Years.

The Meta is probably the Best DIY Library You can find !
http://groupdiy.com/index.php?topic=16013.0
Greatings,
Lothar

 

[dawsonaudio]

Thanks for the response.  I'll re-read through those links again.  I've got a bunch of small transformers that came out of some old Hammond Organs.  I'd probably re-use those and just rewind them.  I think I have about 8 of them.  I thought maybe someone had wound there own transformers for the Pultec eq project or any project for that matter.  It would be nice to have a little step by step as this will be my first go around at it.

Maybe I'll just take apart one of these small transformers and see what I find. 

Thanks.

 

[tubestation]

Hello,
To wind Your own Transformer, specially One s with a high Ratio is a complex Science, before You get Results that Outperform the cheapest OEP Tranny, You really need to know what You  are doing. You can read all Transformer related Posts of the Transformerforumhero Cj, but i don t think You will get offered a  Step by Step Instruction. Reading and learning is the only Way, i think. Too much  Variables to generalise.
It is much more easy and doable to start with winding a Pultec Inductor . You find a lot of  Information in the Meta.
This is a very good Side to start with,
http://www.diygallery.de/DIYsites/inductor.html
The original Pultec is wind on a relativly low Al Molibdäntoroid Core . Today most of the People use high Al Ferrite Potcores to DIY the Pultecinductors because They are avaible and " easy " to wind.
Happy winding
Lothar

 

[lassoharp]

I currently have a couple UTC  A-10's for the interstage transformer if I decide to buy off-the-shelf iron instead. 

You need 1:2 or so for that application.  A-18 gets you closer.

The primary which loads the passive EQ section needs to show it about a 10Kish load if I recall correctly.  You can't really make an A-10 do that, not properly.