[andyr]

Can you advise what is the best kind of switch to use for a line level signal?

I am making up a polarity reversal switch and it seems to me I could either use:
* a 10a mains switch (which is designed to make solid contact for high currents, so should be good for a line-level signal?) or
* an exotic miniature switch - say, gold-plated?

I appreciate the best switch is NO switch but, in order to have the flexibility of polarity inversion, I need a switch so the issue is ... which one will do least damage!

What do you recommend?

Regards,

Andy

[Regis B]

Nais (panasonic) Relay tq2 series + Toshiba ULN2803 Buffer.
Just use the relay when it's not energize.

[andyr]

Nais (panasonic) Relay tq2 series + Toshiba ULN2803 Buffer.
Just use the relay when it's not energize.

Thanks, Regis,

I'm going to use a Nais relay for the signal switching (same as in the GK-1R), powered by a 6v gel-cell with a conventional SPST mini-switch for the voltage.

Regards,

Andy

[Tinker]

Nais (panasonic) Relay tq2 series + Toshiba ULN2803 Buffer.
Just use the relay when it's not energize.

Thanks, Regis,

I'm going to use a Nais relay for the signal switching (same as in the GK-1R), powered by a 6v gel-cell with a conventional SPST mini-switch for the voltage.

If you don't need it to be electronically controlled why don't you just go for a mini toggle or push button, sealed so that the contacts don't oxidise?

If you use relays, the NAIS come in lots of different configurations. Make sure you specify (at least) DPDT if you are going balanced or you might end up with a single pole switch!

T.

[andyr]

If you don't need it to be electronically controlled why don't you just go for a mini toggle or push button, sealed so that the contacts don't oxidise?

If you use relays, the NAIS come in lots of different configurations. Make sure you specify (at least) DPDT if you are going balanced or you might end up with a single pole switch!

T.

Thanks, Tinker ... I'll B using one of Hugh's relays that are in the GK-1; they're DPDT, as I understand it.  Wot I need to do is select either the R&L signal wires OR the inverted R&L signal wires to go through to the output RCAs of my external Phono Stage ... ie. this is an unbalanced environment so the "inversion" is done with a little op-amp circuit.

I first thought of using a more conventional switch - mini-toggle or rotary - but I want to make sure I have a very high quality one (to do minimum damage to the signal!) and I was not aware of any suitable switches.

I know the sealed relays are high quality!

Someone else suggested I could use some Seiden rotary switches, which have been used by people for even phono-level switching, but these are too physically large for my situation.

Hence I arrived at the Nais relay!

D'ya have any better ideas?

Regards,

Andy

[Tinker]

Thanks, Tinker ... I'll B using one of Hugh's relays that are in the GK-1; they're DPDT, as I understand it.  

Actually they are 4PDT, as the GK1 has complete independent switching of the ground path too.

ie. this is an unbalanced environment so the "inversion" is done with a little op-amp circuit.

Good o.

I first thought of using a more conventional switch - mini-toggle or rotary -but I want to make sure I have a very high quality one (to do minimum damage to the signal!) and I was not aware of any suitable switches.

Silver plated wafer rotary, but yes, a pain physically.

Hence I arrived at the Nais relay!
D'ya have any better ideas?

None whatsoever. The relay is a good solution. Certainly an extremely unobstrusive switch. (Hmm... an extreme absence?)

Good one.

T.

[ginger]

Once in a while the accumulated knowledge of 30 yrs comes in handy.

We are always aiming for a low contact resistance switch whether it be a mechanical switch or a relay contact closure. You will hear we "old farts" talk about "wetting current". If there is at least 1 to 5 mA of DC flowing then this is enough to maintain a low contact resistance and just about any old switch or relay will do the job. The problems arise when when we need to switch a pure AC signal (no DC component and therefore no wetting current) - especially low level AC signals. We then need to look for precious metal plated contacts, usually gold or silver. I've had consistently good results with relays with silver plated contacts. I had a quick look in the Farnell and RS Catalogs - both offer a few switches with gold plated contacts.

There you go - something to add to your compendium of useless (well occasionally useful) information.

Cheers,
Ginger