Gainclone considerations (wrt chassis layout)

[Selexus]

Hi everyone,

I'm formulating the final chassis design for my first gainclone (using Brian's boards) and i'd like a little help, please.

Is there a noticable improvement in sound quality when keeping the input wires as short as possible ? With my (basic) understanding of such matters i would have assumed that it was more important to use good chassis connectors (XLR or RCA) and to keep the input routed away from the trafo and PSU, than to be to anal about the actual wire length ?

Also for this 4 channel amp (biamping a single pair of speakers from this one box) would i get better results from using 4 regulator boards and 2 trafo's than 2 boards and 1 larger trafo ?

I'm sure i'll have more questions soon , but if someone could offer an opinion on these i'd be very greatful.

[djQUAN]

the short wire could make the sound better since there is less wire to pick up interference, other than that, I can't think of any other reason.

also, moving the signal wires away from trannys, etc will also improve the sound.

[joensd]

As you already mentioned your priority will be to keep PSU noise away from the input.
I´ve made good experiences taking longer input wire but therefore routing it around the PSU circuitry.
But it also should be as short as possible.
If you worry about it you could use an extension for your pot so that it is physically in the back of the amp near the input.
You could also include separate compartments like here

[Sherman]

Originally posted by Selexus
...
Is there a noticable improvement in sound quality when keeping the input wires as short as possible ? With my (basic) understanding of such matters i would have assumed that it was more important to use good chassis connectors (XLR or RCA) and to keep the input routed away from the trafo and PSU, than to be to anal about the actual wire length ...

The issue is one of interference from radio frequencies or electromagnetic sources. Keeping the wire short makes it less of an "antenna" and helps reduce the possibility of interference.

However by routing the wires away from possible RF/EMI sources inside the case and having a metal, preferably aluminum, case to keep RF/EMI from getting in from the outside you can usually build a quiet amp.

Based on experience I like to use shielded wire between the inputs and the amp. Ground the end of the shield to the ground of the jacks, let the other end "float".