Dedicated earth channels

[Loquah]

Hi all,

Back when I used to design car audio systems for sound quality, I used a trick where we would use a separate amplifier for each channel (i.e. amp 1 would use its 2 channels to separately drive the woofer and tweeter for the left channel and amp 2 would use its 2 channels to separately drive the woofer and tweeter of the right channel). The outcome of this was zero crosstalk once the signal left the head unit.

I'm wondering if it would be possible to replicate this on the S.E.X. and / or if it would bring any benefit.

As far as I can tell, this would simply require running my headphones from the speaker terminals via a 4-pin XLR or similar adapter and possibly disconnecting the heapdphone jack because it seems that until the earth is shared on the headphone jack, the signal paths are completely independent. Is that correct? And if so, will there be any benefit in terms of reduced cross-talk?

[Doc B.]

The ground is common at a power supply filter cap. I don't think there is an issue with cross talk anyway.

[Paul Birkeland]

we would use a separate amplifier for each channel (i.e. amp 1 would use its 2 channels to separately drive the woofer and tweeter for the left channel [...] The outcome of this was zero crosstalk once the signal left the head unit.

[...] it seems that until the earth is shared on the headphone jack, the signal paths are completely independent. Is that correct? And if so, will there be any benefit in terms of reduced cross-talk?

OK, there's a fair amount going on here.  Assuming your head unit had unbalanced (RCA) outputs, the grounds were already shared in the first place.  Additionally, most car amps have the negative speaker lead grounded, which would also be common to both channels.

Separating the grounds of the output transformer secondaries in the SEX amp will not influence the level of cross talk.  Where you decreased the cross talk in your car audio setup was by having two power supplies (which doesn't necessarily require two amplifiers).

In the SEX amp, are you experiencing cross-talk issues?  The C4S upgrade incidentally will improve the cross-talk isolation a bit. 

-PB

[Loquah]

No issues, just exploring an idea while I'm learning the ins and outs of the headphone world.

Thanks for the responses. Seems like it'd be a waste of time given your feedback and how awesome the amp already sounds.

[Paul Birkeland]

If you wanted to travel down a similar path to your car audio experience, you can build a second high voltage supply and separate the two channels.

(You can also build a 2nd SEX amp and have monoblock headphone amps )

[Loquah]

If you wanted to travel down a similar path to your car audio experience, you can build a second high voltage supply and separate the two channels.

(You can also build a 2nd SEX amp and have monoblock headphone amps )

Sshhhh, don't mention the monoblock idea - I'm trying to forget it's possible!

[4krow]

 MONO headphone amps? I think my head just exploded! And I thought going balanced for headphones would be the ultimate.