audio switch/bypass ?

[daemonsgr]

hi all,

I need a bypass selector for:

a PiDAC that can send signal to the denon amp input directly or via a tube preamp.

I have searched in the forum and I've seen a solution with a switch discussed (for input selector thought).

a) All signals are line level, is interference a problem?
b) what sort of switch design do I need? Specific switch?
c) any usable wiring diagram? should I fear ground loops etc?

Thanks

 

[daemonsgr]

Is it that difficult or that simple?!?
Or maybe I dont make sense?!? Heheh

 

[Osvaldo de Banfield]

Your question is difficult to understand: a single audio source to a single audio amp; I don't see why a switch/selector is to be used. For bypass the tube preamp, a simple single pole double way switch is sufficient, a double pole for stereo usage.

 

[russc]

The question is simple to understand.
A diagram would make your answer clearer.

 

[daemonsgr]

Your question is difficult to understand: a single audio source to a single audio amp; I don't see why a switch/selector is to be used. For bypass the tube preamp, a simple single pole double way switch is sufficient, a double pole for stereo usage.

Ok that makes sense. So for line level audio signals there are not “quality” problems (like interference) if you play with pole switches.

My plan is to have a tube preamp sometimes on the signal path, sometimes “clean”.

 

[russc]

To be clear, I was hoping Osvaldo might post a diagram to show how to connect his proposed simple switch.
If not, I may attempt a diagram tomorrow. My solutions are 2 poles per channel or 1 pole and use 2 inputs on your main amplifier.
Otherwise, I have your DAC connected the main amplifier input while still connected to the pre-amp input; which may or may not be a problem.

 

[daemonsgr]

Otherwise, I have your DAC connected the main amplifier input while still connected to the pre-amp input; which may or may not be a problem.

Aha, so only disconnected on the one side. Wont the impedance/resistance influence the signal? Its not like “tapping” a scope probe with 10M resistance.

 

[Osvaldo de Banfield]

To be clear, I was hoping Osvaldo might post a diagram to show how to connect his proposed simple switch.

This is the suggested lay out. Not to complex to understand, certainly.

 

[russc]

I assume then the high impedance tube input does not affect the signal when pre-amp is bypassed. Might be a different story if a low input impedance pre-amp.
If your main amp has source selection then no need for the switch.
Just an RCA splitter per channel.

 

[daemonsgr]

denon has spare input lines indeed...

Regarding input impedance: tube pre has a 10k potentiometer on the input. not very high. What do you think?

Denon usually has 47k I believe.