Best electronic switch for audio signals-logic drive

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Yes, too low S/N ratio especially when it comes to the so (or self?) called High-End :cool:!
Best regards!
You're quite on spot with my latest trials with an old cd player where adding some pleasant noise, i'm masking the unpleasant one . I just found the cheapest way to build "High end" equipment , but i know that "cheap High End" is the most hated quote in the Galaxy !

Superman and Predator are buying their suits from Pierre Calvin too.

I had one chance to work on "Expensive high end" in the past and I know how the market really works and what you really need to make this so called "High End." You can't afford Unhappy Clients an some of them can't get into Pc-Curry's for usual cheap-end as their shoes would risk dust infections.
 
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Wonderful article Jan.
What are those "4007 s.p.dt switches" ?
The 4007 is a triple logic inverter.

There are two versions of the CD4007, one is buffered, the other is unbuffered (4007UB). That one just has 3 pairs of N-P MOSFETs. That's the one I used. It really is just 6 devices in a package ;-)

http://www.ti.com/lit/ds/symlink/cd4007ub.pdf

Jan
 

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Years ago, I designed a telephony gadget where I used a MDAC to set the gain. As I recall, I did find a MDAC that featured log values, but there were some issues about sourcing, so I just used an common 8 bit MDAC and put a table of dB to binary on a sticker. Just 8 bits gives a 48 dB range. I was worried about distortion but in that application it was completely a non-issue.
YouTube

Note that resistor ladders do not have to be R:2R (~=6dB). You can make them 1dB, 2dB, 10dB, and use selector gates to pick a tap instead of summing them. As with any DAC, you will want to mute the output during switching.

You can also PWM an audio signal (~100KHz+) which simplifies the analog part to a single switch.
 
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Also, there will be relatively high signal levels on the switches, which increases distortion. The design in the article I linked to was designed with trying to keep signal levels on switch terminals at all circumstances as small as possible for max linearity.

Important detail indeed.
The on-resistance of J105 is 3 ohms so the voltage over the switch will be 100x lower than your 300 ohms 4007UBs.
However, I did some calculating and your solution still has lower distortion, and does tackle more details so you are still on top Jan.

Any PCBs left?
 
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