Transformer Question

[karbomusic]

Ref: http://www.diystompboxes.com/smfforum/index.php?topic=110793.msg1017702

So, I'm soon going for my third rendition of ^this design. I want to pretty much keep what I have but add transformer isolation. The Jensen JT-MB-EPC looks similar to what I think I want but the impedance is far to low to place it before the buffer if I'm reading correctly. Secondly, that wouldn't work anyway because the buffer is already doing my splitting...

JT-MB-EPC  150:150:150:150  1:1:1:1

Ideally what I want is for at *least* two of the three buffered outputs to be transformer isolated. I'm going the premium transformer route because the cheaper 10k models such as the elcors aren't properly shielded and will hum (been there done that with the first design). This is a bit of a special box so expense isn't a huge barrier so long as I end up with what I want... 1 input, 3 buffered outputs + phase swiches + isolation. This will be used for splitting my guitar signal and driving multiple amps or two amps and into a DAW and so on.

FWIW the one in the link above works beautifully except for times that ground loops enter the picture which is typically easily solved by going through an external isolator. That's what I do now but I would LOVE to have all of this in a 125BB or similar.

Ideas?

[PRR]

> the buffer is already doing my splitting...

So?

The Jensen winding is *known* to work for splitting. You paying for this feature. Use it.

> what I want is for at *least* two of the three buffered outputs to be transformer isolated.
> JT-MB-EPC   1:1:1:1

The DPT version does your job and $40 cheaper.



See nearby thread for links to plans for DPDT phase-reverse switch.

I've paralleled the spare opamps to get good drive to this low-Z transformer.

The drawing assumes split-supply; I believe you will see how to adapt it for single supply and Vref.

[karbomusic]

Thanks Paul, all of the above makes sense.

I may schemo that out as a new design. All good on the Vref and DPDT. I did the DPDT flip on a previous transformer project last year. Stay tuned although it's a couple items down the design/build list.