Transformer Isolated ABY Pedal

[tristanplaysguitar]

Hi

I need to build an A/B/Y pedal, and I'd like to put in an isolation transformer to avoid ground loops. But, it needs to be true bypass with no buffer. Basically a bare minimum passive ABY Switcher with a transformer.

I've found this: http://www.geofex.com/FX_images/humfree2.gif
but it has a buffer.


and this: http://www.tonebone.com/re-bigshot-aby-detail.htm
But I don't know if the radial diagram is a complete schematic. If it is, would this transformer work? http://www.mouser.com/Search/ProductDetail.aspx?R=42TM018-RCvirtualkey21980000virtualkey42TM018-RC

Or does anyone have any other schematics?

Thanks,

Tristan

[PRR]

Transformers have problems, especially at high impedances.

You can not build a naked transformer good enough to pass high-impedance guitar perfectly.

If you buffer, it is not too hard.