Optimum Maximum Effects Per Box

[Brushthrower]

A bit of a "for idiots" question, but I was thinking of making a multi-effects box with some essential, mostly non-distortion effects (compressor, tremolo, octave-up, etc). Would there be a degradation of the signal passing through several effects, and if so would this be remedied by placing a buffer at the beginning and end of the series of circuits?

Cheers!

[anchovie]

I don't know about degradation - they're effects so they'll be changing the signal anyway! 

Buffers are useful for long runs of cable with no other active electronics inbetween or circuits that might load down a guitar pickup, so whether you need one or not is going to be influenced by how much wire your signal goes through with everything in bypass and/or the input impedance of any effect that you might use on its own. Seeing as you can build a buffer with a pinch of components and 10 spare minutes, there's no harm in putting one before the first footswitch in the box and then you'll be ready for anything!

[amptramp]

I generally design circuits for high input impedance and low output impedance with input and output buffers for each circuit as required and all controls between the buffers so there can be no interaction between controls in separate effects.  For a multi-effects box, you also have to consider that the simplest design has a fixed order that the signals go through.  This can be changed by putting each output on a bus and having switch selection of what bus the input of each circuit connects to.  If you are always going to have a fixed order of effects, you can set the output impedance of one stage low enough to not be bothered by the input impedance of the next stage and you may be able to avoid adding buffers to each effect.

I am not a big fan of true bypass and it seems that the "big boys" like Boss and Electro-Harmonix concur.  I prefer a buffered input and output anyway.  Unless you have your own SQA (supplier quality assurance) at the plant where 3PDT switches are made, they quality is variable (usually bad) and switch life is poor.  I have seen a very good 3PDT switch that operated very smoothly and seemed to be high quality - but this was a $420 digital effects pedal where they could afford the SQA.  That was the only good 3PDT I ever saw - the rest have a gritty feel to the actuation and there is no guarantee that if one switch has one pole switch off before the other, that this relationship will remain for all switches, even in the same production lot.  CD4007 switching into a buffer stage can be made silent and reliable using only an SPST or optical switch for long life and good reliability and the circuitry can be initialized to a given state on turn-on and you can add remote switching if you want to rack-mount the effects box.

[mremic01]

I am not a big fan of true bypass and it seems that the "big boys" like Boss and Electro-Harmonix concur.  I prefer a buffered input and output anyway.  Unless you have your own SQA (supplier

Almost always better.

[mremic01]

A bit of a "for idiots" question, but I was thinking of making a multi-effects box with some essential, mostly non-distortion effects (compressor, tremolo, octave-up, etc). Would there be a degradation of the signal passing through several effects, and if so would this be remedied by placing a buffer at the beginning and end of the series of circuits?

Cheers!

It really depends on how you wire it. If each effect has it's own 3PDT, it's no different than having each of the effects in their own box. You might get something inside picking up LFO ticking from a circuit that has it, but a buffer won't help that. Shielded wire might be a good idea, but I wouldn't worry about it unless you're having an issue. A buffer would be useful if you find that the pedal as a whole sucks out some of your high end when all the circuits are bypassed. If you plan on running a buffered pedal before this one, then adding another buffer would be redundant.

[Brushthrower]

Thanks for your considered replies. I was planning to wire each effect with their own 3PDT switch and put them in order as I would on my pedalboard: compressor -> dirt -> modulation. I usually have a buffered effect at the beginning and end of my chain of effects and mostly true-bypass in-between. I think I'll try it first without buffers and add buffers if I find too much tone sucking.

Cheers!