I've made one with 7 fx in it some years ago:
- tillman pre-amp
- fuzz face
- tubescraemer + a custom effect (I can switch between the two)
- Rebote Delay
- Easy Vibe
Every fx has it's own in- and output.
No buffer, no special considerations about power; just an external boss adapter into the dc-jack and an elco 100 µF. Just didn't care about it at the time.
Other than the SHO that sometimes play's up (but that is due to the fact that the transistorsocket is lame), no problems (no buzz or other unwanted noise).
If I would do it again (and I will), I would consider the following:
- internal psu. The adapter is sometimes troublesome in live stage situations
- a cleaner way of wiring. It's a real spaghetti now, but no problems with it.
- a nicer finish.
I'm glad I put the pre-amp in; nice drive to fx and the amp, no loss off tone. Maybe better than a buffer? Or be able to switch between buffer at the input or a pre-amp.
To get rid of the ticking on the easy-vibe, I've put in a RC-filter (100ohm resistor - 100µF elco).