Switch, connector, etc. noise and distortion effects?

[AudioTodd]

Hey have any of our fine members performed (or are aware of any published) noise and distortion measurements of “hardware” items like switches and cable connectors? I’ve seen some comments here at ASR and elsewhere that have posited potential effects of these and other components of measurement rigs on measurement results. It is, of course, typically only mentioned in tests of VERY high performing gear where locating the sources of residual noise and distortion is very difficult.

I’m curious, however, if there is any chance inserting properly designed and executed switch boxes and patch bays and the like could have any material effect on the overall performance of the system as a whole. I would not think so, but...

I’m also curious about everyone’s thoughts on how to be sure switch boxes and patch bays and such are properly built to minimize the influence of various potential sources of noise (oh, and crosstalk, etc.).

I’m hoping for help HERE - I wouldn’t even think of even considering asking these questions in 98% of OTHER forums!!!

 

[amirm]

At the highest levels of performance, connectors do matter. Case in point: the Benchmark AHB2 amplifier. Its speakon connectors had better performance than banana jacks. The speakon connectors were soldered right onto the board whereas the banana jacks had a wire. And connection to them could not be as secure.

Likewise, when testing headphone amplifiers at the extreme of performance, headphone connectors can make a tiny difference.

At anything below this, the impact is negligible as the electronics distort more than connectors/switches.

 

[AudioTodd]

Thanks for the quick reply and I had hoped you would hop on here quickly. I’m the proud owner of more than one AHB2 (all using SpeakOn equipped cables), a LA4, and a DAC3 B and a couple DAC3 HGCs, which is kinda why I asked! These comprise two truly (IMHO) reference level systems, but I enjoy tinkering with other types of equipment as well.

As such, I have lots of equipment, anything from a kit-built SET 300B amp to BJT Class A monoblocks from a very low production manufacturer, that I’ve accumulated over 30+ years and like to put in the chain now and again to hear how things have - and have NOT - changed over the years. I would like to make changing the chain easy, so I’m considering some switch boxes, hence the question. I’m pretty certain, though, that any ill effect would be completely swamped by the characteristics of the units themselves (especially the Single Ended Triode amp!). Thanks for giving your experienced-based opinion validating that.

Note: I will NOT be inserting anything except Benchmark cables between any of the Benchmark units or to the speakers!! Truly astounding sound!

 

[DonH56]

A good patch bay will use good cables well-isolated from each other and high-quality (e.g. Neutrik) connectors. The cables will generally be isolated from the front panel so it can be grounded to the rack. That provides higher immunity from crosstalk and noise while minimizing the opportunity for ground loops and such. The panel with also be stout enough to withstand repeated, rapid, ham-handed (guilty) sound guys slamming connectors in and out under intense time pressure (or perhaps just a bit of frustration; guilty again).

Switches should be break-before-make while maintaining a continuous ground path with low-resistance non-oxidizing contacts, or at least of metals that create conductive oxides. Gold contacts are actually not that great in this application as the gold is soft and wears quickly.

IME/IMO - Don