[b0dhi]

Earlier tonight I temporarily rigged my balanced M^3 to drive my single-ended PK1 earbuds. After picking my jaw up off the ground and reorienting myself, I decided I had to have a more permanent way of using the M^3 and PK1 together.

Since the M^3 drives the Taket H2, balanced GS1000 and other balanced phones, I don't want to rewire it for SE operation.

I thought the laziest and therefore correct solution might be to reterminate the PK1 from SE 3.5mm plug to a 4 conductor 3.5mm plug. Then I could just keep the amp balanced and wire up an adaptor, allowing the PK1 to be run balanced. However, I want to be able to still plug the PK1 into a single-ended device and have it work.

Does anyone out there know whether a 4C 3.5mm plug, when plugged into a 3C jack, shorts the two rear-most rings and gives a common ground?

 

[n_maher]

You first need to know if the PK1 uses 4 conductors all the way from the plug to the drivers (separate + and - for each channel). If it doesn't your stuck from the get go, if it does I'd still suggest that you're not likely to see huge performance gains from running the balanced and in fact may have issues with too much gain. The path of least resistance (no pun intended) would just be to build an adapter that converts your M³'s balanced output to single-ended, which should be easy enough.

 

[b0dhi]

Quote:

Originally Posted by n_maher /img/forum/go_quote.gif You first need to know if the PK1 uses 4 conductors all the way from the plug to the drivers (separate + and - for each channel). If it doesn't your stuck from the get go, if it does I'd still suggest that you're not likely to see huge performance gains from running the balanced and in fact may have issues with too much gain. The path of least resistance (no pun intended) would just be to build an adapter that converts your M³'s balanced output to single-ended, which should be easy enough.

Thanks for your response. The PK1 has one wire running to each earpiece so I'm assuming it must be 4 conductor.

I'm not that picky about running the PK1 balanced or SE, but I wasn't sure if it was safe making bal->SE adaptor because the M^3 synthesises ground and only supplies hot/cold outputs for each channel (which each run off seperate power supplies). In SE config I'm not sure where a safe ground would connect to. The active ground amps are unpopulated on my board, btw.

 

[nikongod]

I have seen both methods of wiring used in little earbuds, and dont know which the yuin uses. Most earbuds use only 3-wires (L, R, Shared ground) from the y-split to the plug. I would email fang if nobody here has a good answer within a few days. He will probably be very happy to learn that people want to use his headphones from such a fantastic amp.

If you find you cant conveniently run the PK-1 balanced You should be able to ground a SE headphone jack to the same place as the input/main ground, in a passive ground arrangement. Please triple check for voltage offsets at the outputs as always.

 

[b0dhi]

Thanks for the help. In case anyone is wondering, a 4C plug will, when connected to a 3C jack, sometimes be shorted to a 3C, and most times not (unfortunately not on my iaudio7). So there goes that idea.

I tried wiring up the M^3 in SE, but whether I used passive/input ground or active ground, there's a lot of interference that sounds like a ground loop.

Also, I tore up my old PK3 and yes, Yuins have 2 conductors per cable from the plug to the earpiece. The PK3 actually sounded very good balanced. I can't be sure, since only one side works, but I'm pretty sure that in SE operation it had an annoying "pit" in the upper midrange which seemed to disappear when driven balanced. This seems to corroborate a graph Cool_Torpedo posted of the HD600 being driven balanced vs SE, whereby the balanced mode seemed to raise a couple of the recessions in the mids by 4dB without altering the rest of the sound.

Though I don't know if I've got the balls to tear up the PK1.