Preferred relay for switching audio sources?

[Taito]

Hi, I'm working on the design of a preamplifier at the moment and would like to know if anyone has found some really good relays for switching audio sources, or has come up with a better way to do it -at this stage, the plan is to incorporate some form of microprocessor control (which I'm pretty sure will require the use of relays).

I've read that mercury-wetted relays are a really good option, but am finding it difficult to locate any.

Any input would be appreciated.

Thanks, Ben

[ralphs99]

Hi Ben,

Reed relays are generally very good for line level use. They are fully sealed so aren't susceptible to contact corrosion. They have higher contact resitance than other types but that doesn't matter in a high impedance circuit. Mercury wetted types have lower contact resistance and less contact bounce. But the industry is phasing out toxic materials so mercury wetted types will be harder to find.
Any standard relay with gold contacts will also work well. Gold contacts are important for circuits that pass no current. Other contact materials rely on the arc formed by opening and closing to burn off oxides and contaminants.
Try Jaycar, Altronics, Farnell, RS for local supply.

Cheers,
Ralph