I want to switch out individual resistors / caps from audio circuit


#1

Hola! I have an audio circuit that I want to switch out individual components from, or change the signal path.

Is an SPDT Analog Switch the correct component I should be looking for?

If so here are some possible candidates I’ve found:



Thanks! Mostly I just want to know if I’m barking up the right tree or if there’s an easier way to do this.


#2

What exactly are you doing? Can you share more information about your circuit? Audio circuit design is rather unconventional. Are you powering everything from a 5 volt rail or a split supply? Are your op amps RRIO? Do you have minimum standards for distortion and dynamic range?


#3

No opamps in the circuit.

Power is +9Vdc, I’d probably make a separate 5 or 5.5V rail for any component I choose (depending on what that component wants)

If it helps, the NF for the small-signal transistors I’m using is NF = 3.0

The audio signal is typically 250 mVp-p, but I call it 1 Vp-p just to be safe.


#4

Ah ha! I found a much better part.

I’m almost positive this is exactly what I’m looking for:


#5

Hey all! I just wanted to update this with the solution and why I chose it. Hopefully it can help anyone stumbling across this thread years from now, ha!

I ended up using an Analog Devices ADG1636 - dual SPDT analog switch.

This particular one has an extremely low Ron at 1.1ohm, which was useful because one of the resistors I’m switching out is only 470 ohms.
Other analog switches had Ron of 600 ohms or 56 ohms, etc (obviously far too high for my purposes).

After narrowing that down, I looked for parts that would support a single-rail supply (gnd to 9v or lower), and settled on the 1636 because it had tested values for a 5V supply rail.

Just wanted to close the loop on this thread :slight_smile: