Solid state switching of signals

[eeka chu]

What would be the cleanest way to switch an AC signal path on and off using solid state?

The signal is only low, a few volts, and since it's a signal I can't really make do with diode voltage drops, which immediately points towards bias / trigger devices where the only drop is from their internal resistance.

I'd prefer not to have to use solid state relays since they're kind of expensive and I need lots of them, nore do I absolutely need their isolation potential.

[Jan Dupont]

For low power signal I (and many others) use this way (T14 and T15 in the attached circuit)

There are other ways, but this is nice and clean

- By the way.... This is from the QUAD 34 preamp

[mzzj]

Originally posted by eeka chu
What would be the cleanest way to switch an AC signal path on and off using solid state?

The signal is only low, a few volts, and since it's a signal I can't really make do with diode voltage drops, which immediately points towards bias / trigger devices where the only drop is from their internal resistance.

I'd prefer not to have to use solid state relays since they're kind of expensive and I need lots of them, nore do I absolutely need their isolation potential.

HC4066 and similar cmos swiches are classically used for things like these. VHC4066 is tad better in on-resistance and maxim-ic for example has improved versions that are still pin compatible with 4066. 4066 on-resistance is variable and varying with signal strengt, somewhere between 50-500ohms so your input impedance after switch has to be enough high.

[Leolabs]

U can try JFET too.Harmon Kardon and NAD do use them in their amplifiers.

[Vidalgo]

For low-current signals, try this way:

No signal distortion introduced.
Switches W1-W3 - any bidirectional type: solid state, relay contacts, etc.
Control: only one switch open at a time.
Need to high-impedance load, or opamp input.

Cheers.