The polarity of DACs

Digital Drive

Upsamplers, DACs, jitter, shakes and analogue withdrawals, this is it.

Dear inmates and music loving audiophiles,
I suspect that the Phillips 1541 DAC and Burr Brown DACs invert polarity. The Magnavox CDB 650 CD player has both its digital output and its analog outputs in polarity so the player is net not inverting CDs. But it has a single inverting op-amp after its 1541 DAC and a non-inverting op-amp in series with its output so if the 1541 DAC is inverting that would be a possible explanation of how the player output is net non-inverting. The NEC CD730 has two 1541 DACs in a dual differential configuration and itâ€™s also has its digital and analog outputs in polarity. If the first 1541 DACâ€™s inverted output is re-inverted by the second 1541 DAC that might explain how it is that the CD730 is net not inverting of CDs. It has a polarity switch on its remote and the polarity indication light on the player agrees with its audio output. I also have a Rotel RCD-975 that has dual differential DACs and itâ€™s non-inverting as is the Adcom GCD-750 with its dual differential Burr Brown DACs. My Adcom GCD-575 with a single Philips 1541 DAC has both its digital and analog outputs inverting as does my Adcom GCD-700 that has only a single Burr Brown DAC. The polarity indicators on both the of the Adcom CD player give the wrong polarity indication.
Perhaps that could explain why so many CD players are inverting, i.e. their DACs are inverting but the designers of their analog circuitry arenâ€™t aware of that fact.
George S. Louis, Perfect Polarity Punditâ„¢

This post is made possible by the generous support of people like you and our sponsors:

Amplified Parts

Topic - The polarity of DACs - georgelouis 08:25:18 03/25/07 (4)

Some further thoughts on DACs - georgelouis 12:55:20 03/25/07 (0)

Here's a link that will help you..... - ThomasW 08:30:09 03/25/07 (2)

that makes sense to me 990 and TDA1541 - herb's go karts 13:48:13 03/25/07 (1)

Re: that makes sense to me 990 and TDA1541 - georgelouis 18:56:52 03/25/07 (0)

You can not post to an archived thread.