[Squalish]

is there any problem with using reed relays to extend a switch that will be handling signal-path stuff into additional poles?

 

[jeffreyj]

Maybe. It depends on many variables but two of the most important w/r/t low-level signal switching are contact material and the way the contacts are actuated (do they slide past each other at any point, which will wipe them clean). Look for a reed relay rated for "dry switching", which is code for "little or no current."

Keep in mind, though, that the benefit of not routing signal-level cables to and from the front panel is often worth the aggravation of implementing a relay switching system!

 

[Squalish]

If the relay is rated for min 1ma rather than dry, would that affect a line-level signal? I would be using the P&B R10-E1-Z8-V350.

 

[jeffreyj]

I checked out the link you posted and the last two contact options (P and L) for the relay type are perfectly fine. Essentially, the contacts need to be plated with a precious metal or mercury-wetted and slide during the make-break sequence to be dry rated.

The 1mA contact rating you referred to was a "typical" rating and as such only conveys what the contacts are expected to be switching for their "typical" lifespan. Gold plated contacts won't last long if they have to switch several amps of current, especially if an inductive load is involved!

Beware, though, that only the last two contact options would be appropriate for the task - all of the others would be very noisy.

 

[Squalish]

eck.

I was referring to the Z contacts - typical 100ma max 2A min 1ma.

My original intent was to have a balanced or 4channel ladder attenuator(8 poles) for the active stage at 50k combined with a balanced or 4channel channel series attenuator(4 poles) for a passive preamp option at 5k. I have a 5p23t switch. Throwing an 8PDT(used as a ST) onto every throw on the last pole was an inelegant solution, but I found a batch quite cheap.

Guess I'll need to find another way to perpetrate this particular excess, or content myself with series and a switched shunt for passive. Or maybe I'll find another source for a mercury-wetted relay, you never know.

 

[jeffreyj]

Quote:

Originally posted by Squalish eck. I was referring to the Z contacts - typical 100ma max 2A min 1ma.

Not a good choice. They'll work fine for a while, but they'll get noisy eventually because not enough current is flowing through them to "wet" the contacts <- actual term!

Quote:

...Throwing an 8PDT(used as a ST) onto every throw on the last pole was an inelegant solution, but I found a batch quite cheap.

Ahhh.... That explains the peculiar selection of relay you posted. I was wondering where in the heck you came up with that one!

Hey, those relays might come in handy for something else... maybe. Okay, not likely, but they were cheap, right?