Hi! Could anyone kindly tell me if it’ll possible to mod headphones with a single ended connection to allow for balanced connection? And if it is, what are the chances to affect their frequency response through possible changes in their acoustic and electrical properties that such modification might (or might not?) possibly introduce?
I’d be very grateful for your insights on this matter, thank you in advance!
Yes, you can. However, this requires two independent lines on each side (L audio plus L ground; R audio plus R ground), and it cannot be done with an external adapter. Some people try to convert just the jack to four lines, but that doesn’t work and it will short out your gear.
There are various people on Etsy.com who will modify single-ended headphones, and surely others.
In my experience there’s only a modest difference in sound when running most headphones single-ended versus balanced. Sometimes no difference, sometimes a bit more clarity / less noise. It’ll depend on your specific headphones and amp.
You’re most likely to hear a difference if your headphones have (very) low impedance drivers and the stock cable has a long common GND (return) wire that only splits to L and R very close to the headphones or inside the cup the cable is attached to (what I call a Y-shaped GND).
As an extreme example, the Verum 1 (mk1) headphones have 8-ohm drivers, Y-shaped GND in the stock cable, and 1.8 ohm(!) wire resistance for the full circuit going out of the amp and back. The crosstalk just from this voltage divider structure is something like -29 dB, and produces an obviously congested soundstage width-wise. Even just switching to a 4-wire cable with separated GNDs for the full length (like a stock HiFiMan cable), without terminating it in a BAL connector (both GNDs connect to the sleeve of the TRS) gets you -15 dB of additional separation and an unmistakeably widened stage.
For less extreme starting conditions the improvement will be less dramatic of course, and especially if you don’t have a Y-shaped GND in the original cable have 150+ ohm drivers, as those don’t “care” about the cable structure.
Thank you very much for your answers, guys! I believe I may benefit from such a mod with both higher crosstalk rejection and power output from my source that’s always very nice to have in surplus, especially when EQ is in use. Hope such a procedure should not have a very high price tag, though, since I’m on a small budget and the headphones in question are only ~$150. But even if it would cost an additional $150, it may pretty well be worth it since it’s not like there are any suitable alternatives for HPs anywhere near this price range anyways. Closed back headphone world is dire… 