My electronics level is: a little knowledge is a dangerous thing.

I want to construct a patch cord for a specific application - I've got a little cheapo chinese S.M.S.L. amp that I picked up on ebay for a project a year or so ago (long enough that the amp I bought is no longer available), that I want to re-purpose. It's more or less like http://www.ebay.com/itm/SMSL-SA36A-...P-12V-Power-/171915274685?hash=item2806f2e9bd.

I'd like to use it as a headphone amp now. Unfortunately it doesn't have a headphone out of any sort, just 4 stereo outs, banana clip (red/black R, red/black L) on back. I'd like to build a patch cord that will bridge between those outs and a headphone jack. I've looked at some circuit diagrams online, and it seems that normal headphone jacks share their common ground, with a positive going to each side.

Finally, the question: how do I wire a patch cord for this application? Can I just tie my two negative (black) wires to the common ground on the jack, and the L/R positives to their respective points? I think that will work, but I'd like input from someone that knows better than me.

If you need more info, let me know

Thanks, guys!

 

You cannot joint the two "negative" outputs of this amplifier together because they are not at the same potential.

 

Thanks for the reply. I wish I knew enough electronics to read the schematic-- unfortunately I don't. I understand your statement to mean that my proposed solution isn't a solution at all, that a simple patch cord can't be built that will tie the speaker outs together into one jack. Is this correct?

 

That's correct, unless you cut the plug off the headphones and split the common connections you can't use this amplifier but it wouldn't be a very good choice for a headphone amplifier so it's not really worth the effort.

 

Ah, I see. Thanks again for the quick responses. You've answered my question so that even I can understand. Much appreciated.

 

You could make it work with 1:1 audio transformers, these would let you tie the output grounds together on the isolated secondary side.

- Again, probably not worth the trouble.