Taking the effects out of an amp and putting them in a pedal.

[gijimmbo]

Hey everyone.  This is my first ever post, so bear with me. 
sorry i also posted this on the digital page, please don't hate me.

I was wondering if anyone could help me out with a problem.
I've got an old Fender Stage 100 DSP head sitting around that i hardly ever use.  i bought it when i didn't really have any effects pedals yet.  I was getting ready to sell it when an idea popped into my head.  Perhaps i could tear it apart and take the effects circuit out and mount it into some kind of small pedal housing (since that is all i ever use it for anyways).  Is this something that is possible and if so would it be extremly hard??  I've built a few simple pedals, tube screamer, ross phaser, ugly face, etc.  and with some skills now under my belt i was thinking it might be do-able.  any help or comments would be awesome. 
thanks for everyones knowledge and patience!!!

[drewl]

Since the effects board and most associated components are on a seperate pc board it should be relatively easy.
You'll need to build a power supply and run leas to the controls.....simple.

[gijimmbo]

thanks for your fast reply!  this is going to rock.

[gijimmbo]

one more quick question.   this might sound stupid and show my noobie-ness, but here goes anyway. 

do you think it will work on regular 9v like other pedals?  if not where should i go from there.?

[jonathan perez]

pictures? schematics?

[gijimmbo]

well, i dug around but apparently there aren't any specifically for that amp.  not a current model, and i didn't really want to pay for them.
however, i found this schematic for the regular fender stage 100 amp (the one without the dsp effects):

http://www.fender.com/support/amp_schematics/pdfs/Stage_100-160_Schematic_-_11x17.pdf


and one for the sfx dsp module:  apareently this is only a service manual and i have no idea if it is the same as what's on mine or not. 

http://www.fender.com/support/amp_schematics/pdfs/SFX-DSP_Module_Schemati2D9.pdf


heres a link for the manual for the actuall amp minus the schematic:  (scroll to page 8 and 9)

http://www.fender.com/support/manuals/pdfs/manuals_elec/guitarpdf/Stage_100_DSP.pdf


no pictures yet, once i get it appart i will throw some pictures up here.  i don't know if this is actually helpful info or not.  but thanks again for helping me out. 

[drewl]

You need to find out how much current the fx board draws.
It might eat 9v's quickly....

[gijimmbo]

cool, thanks i'll give it a try....

[gijimmbo]

I still haven't found the exact schematic for this particular amp, but...
here are some pictures of the initial gut shots.  as you can see the DSP board IS seperate from the main board, and connected via a bus.  however all the pots are connected to the main board with a lot of circitry surrounding them.  do you think it would be easiest to figure out the wiring layout and start from scratch building another board for the pots and stuff or just fire up the dremel and start hacking off the stuff that isn't necessary? (i have a feeling that would be a LOT of work!) If so, could someone please look at the pictures and give me a place to start?!
from the pictures you can see i've tried to focus on the area that is of particular intrest. The first five pots from the right side of the board are what i'm hoping to keep.  looking at the top of the board from right to left they are labled as follows:  "time/rate", "FX select", "FX level", "reverb type", and "reverb level". 
thanks again for your time and patience,
alex

click each picture to enlarge.... for an even bigger enlargement, click on the "view original size" link under each photo....  these are truly HUGE files...zoom in real close if you want.

[dpresley58]

The ribbon cable is obviously carrying the signal and/or power to the DSP board, as well as probably sending it back and forth between the pots.

Seems there are a couple of things you'd want to do...  First, if you don't have one, build a simple audio probe like the one on RG Keen's site, http://www.geofex.com/ under "Tech Tips". As an addendum to that sketch, I built mine using a short length of stiff coax cable as the "probe" part,  instead of using the lead from the capacitor to probe with. By using one of the rubber boots from an old coax cable, I could tuck the cap inside of it.

Regardless, armed with that and a multimeter, figure out what (and where) the voltage is coming into the effect board off the main board. Use the audio probe (putting a guitar signal through the amp, of course) to help you determine where the signal is coming in and out of the effect board. You'll be miles ahead of the game with those three bits of info.