woolltmoof Posted February 17, 2019 Posted February 17, 2019 (edited) Hello All I certainly can't say I'm an expert in audio, and know even less about electronics. I'm hoping for some answers to a few questions primarily to do with earthing/grounding, and also how amps connected to the same DAC may influence each other. I've been undertaking some A/B tests using a 3.5 mm A/B switch, an RCA A/B switch, and a 4-pin XLR one, which I'd modified from a 3-pin switch. All switches were Sescom switches, bi-directional, and a photo of the XLR version is below, and the setups relevant to my questions are Config 1 and Config 2 below. The original wiring diagram of the 3pin switch is below, and it's purpose in pro-audio is naturally going to be different to hifi (mono long cable runs vs mono/stereo short cable runs, comparatively). Note that whether the pin numbering is actually correct I don't know, but I'm not sure that it really matters for these questions. So my questions: 3-pin XLR switch 1) With the cable shield being passed to pin 1, does joining all three connector grounds do anything? 2) Given pin 1 isn't switched, won't whatever interference collected by the A/B shields be passed through to each other and whatever the I/O is (and vice versa)? If so, is this an issue and how? 4-pin XLR switch 3) Assuming either the Config 1 or Config 2 setup is being used, and the XLR cables between the switch and the Amps do have the shields soldered to the connector housing, if the connector housings were electrically connected like they were with the 3-pin setup, will there be any impact on the signals from either Amp to the headphones? 4) Some headphone cables (with shields) either do or don't have the shields soldered to the connector. Assuming all connectors in the switch are electrically connected like the 3-pin setup, will there be any difference in the sound signature with a shielded vs non-shielded headphone cable? Config 1 vs Config 2 5) Using one DAC as per Config 2, two 3 pin XLR (or RCA cables) will be needed with a Y-splitter. This electrically connects both Amps and assuming they're both running, will one Amp influence the other? That is, will the signal change? Thanks in advance for any responses Edited February 17, 2019 by woolltmoof sequence of images
Recommended Posts