Digital Audio transformers

[Jocko Homo]

Hairy Holler:

Are you giving me the "Italian salute"? Or just accusing me of knowing what I'm doing. I dunno 'bout that........I went to "bootcamp" at the Football Institute of NoTechnology.

The problem I see with your approach is that you cannot expect your brilliant transformer thingie to behave exactly as you want when you can't control what the idiots on the ends have done. ANd you know they are idiots. Some DACs don't even bother terminating the input. Or put some horrid low-pass filter on it. And then there is that wretched transformer Philips puts on evertything they build. Great for EMI, but too bad it can't pass a square wave. (You need to pass the 7th harmonic to make it look good.)

But never mind that........our buddy is going to hook up something to that crudbucket Crystal receiver, and when it sounds like doo-doo, he is going to blame his surplus transformer. The only approach that works is to minimize reflections (transformer or not), and you can't do that with a nasty Schmitt trigger input. So why don't you give him a nice ACTIVE circuit that he can shove in front of it.

And transformer too, if you want.

Put it on a plate, son. You'll enjoy it better.

Jocko

[Sandor]

Originally Posted by lohk

Here is a suggestion for a DIY SPDIF transformer. This word perfect to get full ground isolation, I am not really sure if it is a genuine high-end solution:

You will need a 6.3mm ferrite ring core (like Siemens B64290-K37-X830)
and 0.4mm isolated wire.
You can solder this littler transformer between two ends of RG59B coaxial wire without a box.

You need six windings for each side like this:

screen----- --------center
6w core 6w
center----- --------screen


Absolute phase is not significant (biphase coding).

5 windings to 7 windings could make a AES/EBU transformer.

regards
Klaus

could you, please, provide more information about the construction of the transformer? The schema is not clear to me. Do you use a bifilar winding tecnique?
Regards.
Paul