20k:20k CT xformer use?

[kiira]

I'm building a tube pre from my junk box while I'm waiting for parts and money to arrive - I think this thing is a black UTC ??? but was wondering could I use it somehow on the output -- half the winding maybe assuming I got the impedance of the output stage ok?

Kiira

 

[gyraf]

..would probably work best as an input transformer..

 

[Michael Krusch]

Are you sure that this transfomer is 20,000kOhm (20MOhm), not 20,000Ohm (20kOhm)?

 

[kiira]

[quote author="Michael Krusch"]Are you sure that this transfomer is 20,000kOhm (20MOhm), not 20,000Ohm (20kOhm)?[/quote]

oops yes of course 20K not 20000k. Darn I have a dozen input xformers and nothing for output.

It's the black one on the right. I also have a Thrdarson 1:10, Thrdorson 1:20, a Thordarson 2:1 interstage (the round can), an A10 and some other stuff.

Kiira

 

[Michael Krusch]

Nice collection! :thumb:

 

[dale116dot7]

I would say the best use of that transformer would be the input of an Altec 436C-type compressor, or if you want an interstage transformer and a push-pull output you might find it useful for that. Or maybe a line/instrument input? I think too low of an impedance for and output stage.

 

[kiira]

[quote author="dale116dot7"]I would say the best use of that transformer would be the input of an Altec 436C-type compressor, or if you want an interstage transformer and a push-pull output you might find it useful for that. Or maybe a line/instrument input? I think too low of an impedance for and output stage.[/quote]

Oh yeah instrument in would be good I think too. You meant too high for output right?

thanks,

Kiira

 

[dale116dot7]

Yes, I just typed it in wrong.

 

[CJ]

Kiira, you can turn an input around and use it as an output in some cases.
Depends if there is going to be DC on the winding, etc.

An A-10 could be reversed in a parafeed circuit. The 10:1 ratio might cut level too much, so maybe just use the winding from the center tap to either leg. This would make it a 5:1, pretty close to the 4:1 ratio of the A-24. The core is the same, so don't worry about saturation. 15 db.

cj

 

[kiira]

Thanks CJ I didn't think of that. I remembered I also have a pair of Haufe 1:4 too that I could maybe reverse... they're nice and small though and would be better on some SS board design I think.

I also have this Thordarson 20A17 1:2 10K:40k CT too that might be ok on an output. They call it an interstage xformer.

Kiira

 

[CJ]

That innerstage would be just the ticket for the line amp in a Pultec EQP-1A.
The Triad HS-29 (Pultec innerstage) goes for around 250 bucks a pop (jeez, I remember butchering one of those!), which is why most folks give up and switch to the S.E. MEQ type circuit. I like the push pull amp a little better. Less noise.

cj

Speaking of innerstage iron, this UA X-former is a good deal:

xfmr

 

[kiira]

[quote author="CJ"]That innerstage would be just the ticket for the line amp in a Pultec EQP-1A.
The Triad HS-29 (Pultec innerstage) goes for around 250 bucks a pop (jeez, I remember butchering one of those!), which is why most folks give up and switch to the S.E. MEQ type circuit. I like the push pull amp a little better. Less noise.

[/quote]

Oh excellent. I wanted to build a eqp-1a with the interstage xformer and I have a UTC 600:600 I could use on the input too.

Speaking of innerstage iron, this UA X-former is a good deal:

xfmr

For $20 that seems like a really good deal

Kiira