Multi effects box question

[Lead2]

Hi all,

I have just been getting back into guitars after a longish break.. I found an old beat up fender lead 2 that I had and decided to do it up. All going very well.
That led me onto how I was going to hear the thing?? I found this site and was more excited than I have been in quite a while. Maybe even a little too excited.... Anyways....
I have ordered bits to start some builds but would like a bit of advice.
What I would like to do is build a multi effects box. It would have:
Overdrive, compressor, chorus, delay, reverb and a noisy cricket to give me an output I can use .
The box would probably be a 1u or 2u enclosure. All pots and switches will be mounted on the front but on the back there would be a series of jacks that have breaking contact on them. The idea is that in normal mode all of the effects would be in a certain order with nothing plugged in. If you wanted to change the order of the effects you could plug in cables and break the original path with a new one. Has anyone tried this before? I wire up a LOT of patchbays for studios so I would be used to this kind of wiring but never tried it with guitar level stuff..
Is there any big no no's about putting them all in the one box? If I need to be able to switch them by foot in the future I will add relays that will mimic the switches that can be controlled from a foot switch..

Many thanks and sorry about the long post...

[IvIark]

The patch bay idea should be fine, as long as each effect has an input and output you could put them in any order that you like.  I'd suggest having a buffer at the beginning so that the signal won't get loaded down with a run of all true bypass effects and the added capacitance you'll get from multiple sockets and patch cables.

In terms of the effects themselves, I'd probably recommend the supply coming into its own board with a big filter cap and then spurring off to each effect as required, and would suggest a low value current limiting resistor such as 100R in series with each.  Shielded cable will probably be a good idea for input and output sockets (and maybe even the pots if you can) because they'll be a lot of wires in there and lots of potential places where you may get interference which can cause whines and squeals.

Apart from those additional measures I'd say just go for it.  Those things may help prevent additional noise, but ultimately there isn't a lot of difference between multiple effects in one box, and multiple boxes of effects with the usual daisy chained supply and a common ground.  I actually want to do something similar in a 2U box so that I can put my most used effects in there without having to use the real things on a rack tray.  And I wanted to do one with 7 x BJF Electronics effects in called a Box of Bjorn   I love the idea of having a few different rack setups and just pulling them out and using another one when I get the urge.  I'll get round to it one day.

[Lead2]

Thanks for the quick reply. I will do all as you suggested above, great advice...
On the buffer suggestion, if a pedal circuit has a buffer at the input should I bypass it so I would have just one buffer at the input and one at the output (before the cricket)?
Would you suggest a transistor or opamp buffer?

Thanks again..

[Jopn]

Hey Lead2,

I've done this patchbay approach many times and you definitely have the right idea.  You'll want to have your first Output connected to your second Input through the switched connections so that it'll break the connection when something is plugged in.  I did this for a friend who plays a Charlie Hunter style 8 string with separate outputs for the bass and guitar strings.  That way, above and beyond order switching, he could either run the box as a standard dual effect for one "instrument" or patch different "instruments" through the different effects.  

My favorite example of this was a dual Muff where we set him up with a Triangle era for his guitar signal, and Green Russian for his bass signal.  Similar tweakable sounds for both parts of his instrument, but with the option of using that same box just for a "boring" 6 string where he can run one side into the other, and patch out of order if he so desired.  Or even patch different effects in between the two sides (a la effects loop).

If you're only doing 2 effects, then a pre and post buffer might be a bit overkill, but certainly won't hurt anything.  There's no worry about there being 2 buffers in a row, so removing the buffers from the effects shouldn't be necessary.  But this is really where fun starts, since you can start removing redundancy in the design and truly make it your own.  Really just depends on your motivation.

What I would do, personally, is build it without buffers but in an enclosure that would allow me to add them if I deemed necessary.  Then build a little 1590a with a buffer to troubleshoot if you suspect that you may benefit from it.  There are many well respected buffers around, both of the transistor and opamp variety.  Since the goal of a buffer is fairly well defined, any of these popular builds should do you well despite their different implementations.  In other words, I would choose based on what's in my parts bin ;)

[Lead2]

Thanks so much for the replies. Very very helpful info here. It will be a while before I get this underway properly but I'm busy building up stocks and preping boards :-)