G 1176 (L-N) - audio transformers ratio options

[saint gillis]

  Hi everybody, I wish to build a stereo 1176 Compressor.
Is it possible to use a LL 1517 output transformer (http://www.lundahl.se/pdf/1517.pdf) instead of 5402 (http://www.lundahl.se/pdf/5402.pdf) ? If it is possible how to wire them?
  Another question : there are 2 windings in Lundahl transformers, is it possible to use a single transformer for two 1176 compressors in the same box?

 

[CJ]

unfortunately you need separate transformers otherwise it will be crosstalk city.

 

[saint gillis]

Thank you! I understand.

Now I'm a bit confused concerning the transformers options, I've read Mnats infos concerning that (http://mnats.net/1176_revision_j.html)
- He says it is sometimes prefered to use a 2:1 input transformer instead of 1:2, and a 1:2 output transformer instead of 2:1 -

If I use a LL1517 (http://www.lundahl.se/pdf/1517.pdf) should I use pin 1&3 for input and 7&11 for output (1:2 ratio) ?
What about choosing a 1:1 ratio for the output transformer? Could it be a good thing? Maybe it depends also on the input option choosen?

For the input transformers, I have LL1521 (http://www.lundahl.se/sidor/old_types.html), there is a subject concerning them http://www.groupdiy.com/index.php?topic=20993.0, their ratio is 1+1 : 2.28 seems to be only 1 output winding... Should I use it with a 1 : 2.28 ratio or rather with a 2 : 2.28 ratio ?

 

[saint gillis]

Hi!
I ve changed the topic title because my questions don't only concern output transformers but both input & output transformers...

 

[CJ]

Output:

for 1:2 ratio you want to parallel the pri windings and series the sec windings

so on the pri strap 1 and 6,  strap 3 and 4,
you can probably figure out how to do the sec in series,
(hint: there is a drawing at the bottom of the data sheet)


Input:  try it as 2:2.28, you can always change it back if you need more gain,

 

[saint gillis]

Thanx for the advice!
I ll try it, maybe I ll try all the options, all these considerations are still difficult to understand...