Headphone and speaker out

[rockgardenlove]

Hey, so I've built an amp with a Gainclone and a small op-amp based headphone amp inside.
The Gainclone runs off a bipolar +/- 35v supply.
Using LM317 and LM337 regulators I created an +/- 18v supply to power the headphone amp and other preamp gears. This hooks up to the bipolar 35v supply.

Now, what I want to do is have a switch to select the output. How should I go about doing this? I don't want to use one of the outputs and have the other idling, I want to actually turn off the circuit not being used.
Can I disconnect V+ or V-? Will that work? Do I need to disconnect both?

I'm afraid I may be limited by the number of poles I have to switch with.
If I get a DPDT, I need one pole to switch the input and then the other switch would need to somehow control the power supplies.

Any ideas?
Thanks!

 

[pacificblue]

Use an SPST switch and add two relays. One DPDT power relay (e. g. Omron G2R-S) for the power supply to switch V+ and V- and a small signal relay (e. g. Omron G6K) for the two input channels. That keeps the different potentials apart and allows for short paths.

The G2R-S is available with built-in suppressor diode. You have to add one to the G6K.

 

[Plammox]

connection of signal GND?

When switching sources in a pre-amp, what is the best option for wiring up the relays?

Using G6K should I use one relay to switch both signal and ground of a single input, or would it be advisable to wire all the signal GNDs together and only switch the signals? (one relay for 2 signals?)

Any concerns about the latter approach?

BR,
Lars

 

[rockgardenlove]

Mmmmk so I'm doing this right now. Is this going to present a significant current drain on my transformer? I've got 2 relays for signals and a heavier duty one for power switching.
Is there a more efficient (power wise) way of doing this that anybody could suggest me?

Thanks!