Relays and Switches for Low Level Mic Signals

Been using TQ2 relays for line level signals.  Do you need any special type of relay for mic signals?

Also for push-button switches,  are gold contacts necessary for mic signals? Some app notes specify them.

The thing with gold switches is longevity and more pollution inmunity, specially important with low level signal such as microphones, I know this well, if only my MCI console had gold plated switches, I would'nt have to replace all of them. Gold is great for contacts, patch cables, XLR connectors, etc.. I prefer investing on gold connectors.

For the MCI did the mic and line switches all go at the same time? From what I have read larger signals have a better chance to pierce through any oxidation.

john12ax7 said:

For the MCI did the mic and line switches all go at the same time? From what I have read larger signals have a better chance to pierce through any oxidation.

Click to expand...

The switches used in the MCI are Shadow multipole push button switches, they are one of the main reasons for intermittencies in the console (they dont call it Muncy Crunchy Intermittent for nothing). AFAIK most of the contact to contact electron transmission is due to an effect called quantum tunneling (https://en.wikipedia.org/wiki/Quantum_tunnelling) oxidation represents a higher potential barrier, so yeah, larger signals have a better chance to pierce through oxidation than lower level signals, which is why I believe gold is the way to go with contacts and switches, specially if you are switching MIC level signals like a polarity flip switch, also patch cables are nice to have with gold plated contacts.

I dont believe in using stuff like silver solder, or silver coated audio cables, but gold for contacts and switches, for sure is a great investment.

I ran console checkout when we were shipping the 416's. The Schadow switches had silver plated contacts; that is why they are failing. By the way I am now 83 yrs. old.

Bill Wilson said:

I ran console checkout when we were shipping the 416's. The Schadow switches had silver plated contacts; that is why they are failing. By the way I am now 83 yrs. old.

Click to expand...

Yeah, I've talked to people involved in the design of the 500 series and they basically said something like "We didn't expect people would still be using these things after 40 plus years", yet they were built like a tank! replacing the switches with gold contacts, replacing capacitors and the molex connectors with gold molex and some pots will make the console almost as good as new.