API 2503 transformer

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if you use a twist drill, you can time the amount of time the drill runs at the same speed (why not flat out?) to give you the same twists per inch,

using twisted wire instead of quad means you will get the same results no matter which leads you use for color coded hookup wire,

with quad you might be using the two inner wires for pri, or two outer, or 1 and 3, get it?  capacitance might be a little \different between wires, not so with the twisted wire,

 
CJ said:
if you use a twist drill, you can time the amount of time the drill runs at the same speed (why not flat out?) to give you the same twists per inch,
Considering the mean turn length of about 4 inches and the total wire length of about 200 ft, a good enough precision can be attained by just looking at the coiled wire.
 
Hi, I'm looking for information to build 2503 but the https://vacuumbrain.uk page is down. I guess this transformer is pretty straightforward, but I have some doubts. This will serve for the output of 554 Eq.
A greeting !



 
extrepito said:
Hi, I'm looking for information to build 2503 but the https://vacuumbrain.uk page is down. I guess this transformer is pretty straightforward, but I have some doubts. This will serve for the output of 554 Eq.
A greeting !
https://groupdiy.com/index.php?topic=74165.msg938988
 
extrepito said:
Hi, I'm looking for information to build 2503 but the https://vacuumbrain.uk page is down. I guess this transformer is pretty straightforward, but I have some doubts. This will serve for the output of 554 Eq.
A greeting !

Yes 2503 will serve 554 eq....Volker put link where is CJ's API's transformers winding diagrams...
 
iprovlek said:
Yes that is company that doing wires from 1939!!!

I asked for this particularly wire 4 twisted 0.28mm gauge wire!!!

Isn't that cheap wire but it worth it! Especial when you doing lot of them...


I didn't made any input trannie but that is My next wish!!!


You have recipe for input for API on CJ site that I sent you!!!

I did API 1604 inspired 16 channels mixer, lots of job,time,money and endless soldering...

So need it lot of trannies....

Congrats for the great work here.
Do you remember how many meters of twisted wire have you ordered to make 16 of them?
There's a calculated total length (straight and twisted) on the CJ receip but I'd like to have a confirm in European measure (meters).

Do you used this lams?

https://www.don-audio.com/Edcor-EI63-12-Strand-M-6-29-Gauge-0014-0355mm-line-grain-oriented-silicon-steel-lamination

If yes, with this pack/set of lams how many transformers can you make?

Many thanks
 
Hi Aleguitarpro!

I use 30m...for testing,but finished with buying Litz wire from PACK LITZ WIRE company!They have 0.28mm of

4 twisted wire!

Yes I use that lams from Edcor,you have on first site I told everything that I used...

It can be done about almost 20 pieces....

But next one batch of it I bought laminations from Italy!

Best
Ivan
 
iprovlek said:
Hi Aleguitarpro!

I use 30m...for testing,but finished with buying Litz wire from PACK LITZ WIRE company!They have 0.28mm of

4 twisted wire!

Yes I use that lams from Edcor,you have on first site I told everything that I used...

It can be done about almost 20 pieces....

But next one batch of it I bought laminations from Italy!

Best
Ivan

Hi Ivan, thanks for your fast reply.
Yes, I mean how many meters of Litz 0.28mm of 4 twisted wires from PACK LITZ WIRE?
30 m?
Great to know that I can do about 20 transformers with edcor set.
I repaired several transformers but these API seems very easy to do, especially with an already twisted 4 wires.
I live in Italy.
You bought lams from Novarria elettronica, Milan?
Because I searched for a suitable type on their catalogue but I'm not sure about lams dimension I need to use from their website.
Thanks for help!
 
Aleguitarpro you need about 30m for one trannie...That CJ explained, you have that info on forum!

EI63(US) is practically EI48(EU)..... so you can go with EI48 for 2503 trannie without any doubts...to be correct EI625 is the US measure for lams of this trannie!


About winding, you can use 4 wire in same time for winding ,you get the same effect, and sound the same!

 
I just wound a couple of versions of the 2503 onto a bigger bobbin and lams I think they are ei75 and had 4 bobbins of 0.25mm which I then wound onto bobbin then twisted onto another bobbin then put back on, 250 turns and hit 11ohms per wind with 130mh , they sound pretty good! ;)
 
Spencerleehorton said:
I just wound a couple of versions of the 2503 onto a bigger bobbin and lams I think they are ei75 and had 4 bobbins of 0.25mm which I then wound onto bobbin then twisted onto another bobbin then put back on, 250 turns and hit 11ohms per wind with 130mh , they sound pretty good! ;)

I built mine using Litz wire.
I tried to use 4 wires twisting them but it's a lot of work and twists are not regular.
I haven't understand your procedure to wound bobbins and them twist.
I wound 4 different bobbins (about 340 turns to be sure to have about 280 turns available), then use the 4 different single bobbins/wires to twist into another bobbin.
Then I used the twisted 4 wires to wound bobbin of 2503 clone.
If someone has a easier approach would be great.
I haven't wound a 2503 with 4 single wires as suggested in blueprint.
The one with Litz are linear and sounds great
 
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