Looking for unbalanced to balanced transformer

[merlin el mago]

I am looking for unbalanced to balanced transformer like Lundhal, Sowter, etc. Could you recommend me a particular model & the way to connect the wires?

 

[Pano]

Do you need an input transformer? Just about any of good the 1:1 models will do, Jensen, Cinemag, Edcor, Lundhal, old Peerless, etc.

Connect one side of the primary to signal hot, the other to ground. Connect the wires of the secondary to your balanced circuit.

 

[merlin el mago]

So I just to ask 1:1 models, this one Lundhal LL6404 is OK?

http://www.lundahl.se/pdfs/datash/6404.pdf

 

[Pano]

Yes, that should do the trick. Sometimes you need to connect the center tap to ground, and this model has no center tap. Usually not a problem, tho.

 

[merlin el mago]

Thank you Pano.

 

[merlin el mago]

To have a gain of +3 dBs like the balanced signal how many turns ratio must have the step up transformer?

 

[zigzagflux]

Turns ratio follows voltage ratio. 3dB = 20log(1.41), so that would be 1:1.41 turns ratio. 6dB would be twice the gain [20log(2)], which is 1:2. You will probably be more successful finding a 1:2 step up than a 1:1.41.

 

[Pano]

Yep, I've had some 1:1.41 transformers custom made, but never seen any in a catalog. 1:2 will do fine.

 

[merlin el mago]

The Lundahl LL7101 can do the trick?

http://www.lundahl.se/pdfs/datash/7101.pdf

 

[David Davenport]

The LL1690 works for me.

http://www.lundahl.se/pdfs/datash/1690.pdf

 

[mikvous]

Would one of the suggested transformers be good for converting the single ended output of a preamplifier to balanced?

 

[zigzagflux]

Probably- you would want to go parafeed. K&K Audio would be a good place to discuss using either of those transformers as such.

 

[Speedskater]

It would be good to read some of the Bill Whitlok transformer papers:

JENSEN TRANSFORMERS, INC. - APPLICATION PAPERS AND SCHEMATICS

Especially the audio transformer design chapter:

http://www.jensen-transformers.com/an/Audio Transformers Chapter.pdf

 

[merlin el mago]

It would be good to read some of the Bill Whitlok transformer papers:

JENSEN TRANSFORMERS, INC. - APPLICATION PAPERS AND SCHEMATICS

Especially the audio transformer design chapter:

http://www.jensen-transformers.com/an/Audio Transformers Chapter.pdf

Thank you very much Kevin

 

[Shoog]

Just came across this OEP transformer;

Technical Reference

I have used one of there other input transformers as a phase splitter on a power amp. Worked out reasonably well for a cheap component.

Shoog

 

[merlin el mago]

The transformer is fro my friend that wants to convert the unbalanced output of the tube preamp CAT SL1-Signature +26dB of gain to balanced amp Pass X clone ALEPH-X - Pass Labs Clone Class-A amplifier PCB & schematic I have the idea to put the unbalanced to balanced transformer inside the Pass X clone. Still can be good the same advice?

TIA
Felipe

 

[merlin el mago]

Please help.