ABSOLUTE Phase Switch

hifiguy · « **on:** 15 Apr 2006, 10:44 pm »

Where can I get a diagram of how to do this correctly and safely on the power amp output side via the speaker cable(s). Bi wired.

hifiguy

diy_freak · « **Reply #1 on:** 16 Apr 2006, 12:25 am »

Quote from: hifiguy

Where can I get a diagram of how to do this correctly and safely on the power amp output side via the speaker cable(s). Bi wired.

hifiguy

Just swap the wires (+ and - (or black/red and so on)) on all of the speakerinputs. Let us know wether you here any difference...

Safely done means turning off the amp.

Occam · « **Reply #2 on:** 16 Apr 2006, 03:39 am »

http://www.1728.com/project2.htm
Go down about 4/5th down the page to
'DPDT switch wired for phase reversal'
one per channel

hifiguy · « **Reply #3 on:** 31 Oct 2006, 07:20 pm »

Thanks!

Russell Dawkins · « **Reply #4 on:** 31 Oct 2006, 09:46 pm »

If you happen to be in the market for a DAC as well, you can accomplish this with the Lavry Black DA10 ($1000) in the digital domain thus eliminating the need to shut down your amps before changing phase, as you would be prudent to do even with the DPDT switch.
It has phase reverse, mono and three digital inputs.

andyr · « **Reply #5 on:** 2 Nov 2006, 05:14 am »

Quote from: hifiguy on 15 Apr 2006, 10:44 pm

Where can I get a diagram of how to do this correctly and safely on the power amp output side via the speaker cable(s). Bi wired.

hifiguy

hifiguy,

Of course, the downside of using the DPDT switches as per Occam's suggestion (you'll need 2 per channel if you are bi-wired) is that you now always have a switch contact in the signal path - which is going to degrade your music. And you probably won't turn off your power amp every time you flick the switch ... which the others have pointed out is advised, so you may give your amps some trouble.

Much better to do it the digital domain (if you listen to silver discs) as per Russell's suggestion. If you listen to vinyl and have a line-stage preamp which accepts balanced inputs, then you could do it with a DPDT switch there too ... but again, you would be interposing a switch contact. I added a phase reversal circuit to one of my phono stages (from www.sound.au.com) and found - by direct comparison to an identical phono stage which didn't have it - that my soundstage suffered

So I ripped it out ... and have stopped obsessing about correct absolute polarity!

And unless your speakers are single driver (with no XOs) or only use 1st order XOs, you probably won't be able to hear "corract absolute polarity" vs. "reversed" anyway!!

Regards,

Andy