# QA403 Are + - outputs independent?

**URL:** <https://forum.quantasylum.com/t/qa403-are-outputs-independent/1861>\
**Category:** Uncategorized\
**Created:** [May 8, 2025, 7:25am UTC](https://forum.quantasylum.com/t/qa403-are-outputs-independent/1861 "2025-05-08T07:25:04Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Sven](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@Sven](https://forum.quantasylum.com/u/Sven)\
**Post date:** [May 8, 2025, 7:25am UTC](https://forum.quantasylum.com/t/qa403-are-outputs-independent/1861/1 "2025-05-08T07:25:04Z")

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Since I did not find a schematic or function sheme for the outputs the question is whether the load on the + output will also incluence the - output ? Since the outputs are not really floating and referenct to “ground” I assume that there is no cross connecion. Some other audio hardware balanced output may have such a cross connection which has influence from one pole to the other. How is it managed at the QA403 ?

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**Author:** ![restorer-john](https://avatars.discourse-cdn.com/v4/letter/r/b5a626/32.png) [@restorer-john](https://forum.quantasylum.com/u/restorer-john)\
**Post date:** [May 9, 2025, 7:47am UTC](https://forum.quantasylum.com/t/qa403-are-outputs-independent/1861/2 "2025-05-09T07:47:16Z")

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AFAIK, the outputs are derived from the differential outputs from the D/A converter, buffered, amplified and attenuated (relays) using several opamps to give the output range we have. I would expect the load on a positive output would not affect the negative output, unless it was so severe as to cause supply fluctuation.

The output impedance of the QA403 is ~100R per leg SE, so 200R for differential.