Originally Posted by anwaypasible
contact the family and get them to build you some metal specific for the input of the preamp .. it could act like a filter to clean things up tremendously.
If a switch acts like a filter for analog audio, it is so screwed up that I can't even comprehend of such a thing.
Interestingly enough, move the frequencies up by a factor of a thousand or more, from 20 KHz to 20 MHz, and you're talking PC video and switches and the wiring associated with them can actually cause visible filtering and reliably perceptible degradation. There is nothing about that which can be reasonably be translated down into audio frequencies.
Originally Posted by gizmologist
Most switches like this are what the pros call "glitch switches". They are simply cheap leaf slide switches with mechanical interlocks. The switches found in the old DB-9 and 15 pin VGA cable rotary switches for computer source select are INFINITELY better grade and more robust. They are totally passive and operate as break before make. You could use one oof these with absolutely no degradation of the audio at all. Simply have some adapter cables made with DB-9 or 15 on one end and 2 RCAs on the other. You would be surprised as the commion use of such simple switches in the professional audio visual presentation business and the broadcast industry.
I almost hesitate to put my esteemed associate Gizmologist's words in the same post as the ones I responded to above, because I respect him and his obvious depth of real world experience, but in the interest of compactness...
I guess I agree that cheap slide switches are worse than cheap rotary switches, at least a little. On balance a well-made slide switch (e.g. C&K) can be really pretty good. For example:
This is solid molded slide switch by C&K that costs about 10 times as much as the standard product from the same factory and probably close to 100 times more than the cheapest garbage that is out there. IME the cheaper C&K is still a really pretty good switch. And, they can make slide switches that are make-before-break.
However, the basic point that switches can be all over the map quality-wise is very true. Its not about pacific rim sourcing, because they will make whatever you are willing to accept from them and pay for, and if you hold out for quality, they can supply it.
Using the right switch for the job at hand is very important. Switching line level audio is relatively easy, and most audible problems due to switches come when they are essentially broken, including getting dirty. If I needed a stereo switch to expand the inputs on something with RCA jacks, I'd be tempted to go find a little die-cast box and pop a nicely-made DPDT toggle switch into it.