Another TS/BD build...

Started by rove, July 31, 2006, 11:58:44 PM

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rove

I have a bass drive pedal that I use in my guitar rig and I plan to build a clone of it to complete my custom pedal setup.  I want to build essentially a bass drive which, as I understand it, is similar to a full drive and a tube screamer.  Ideally I would like to use a tubescreamer pcb (as they are readily available) with the following mods: omit tone control (i always leave this knob at 90% anyways, so maybe a R value equalling that setting in place of the pot), permanent comp cut mode (I always leave the pedal in comp cut any ways), boost mod (as on bass drive), and changing the caps for more bass (also as in bass drive)--as I understand it there are two, I think I know which ones from looking inside the full drive and the bass drive pedals I have on hand, still not sure of their part designations.  In the planning stage now, but I know I would like to fit it into a BB size box and run it off of +18v via 2 batteries.  I am in the midst of poring over the respective schematics, the pedals on hand, and this forum, and thought i would go ahead and post in case anybody had any suggestions.
otherwise I will post how it goes...

petemoore

Convention creates following, following creates convention.

rove

So I went ahead with this build, and, while I considered breadboarding, I decided to just go for it.  Plugged the pedal in first time and just got a wooshing sound, no gtr signal.  so I undid all the mods and have it wired up pretty much stock except for a few parts replacements (c9, c5).  A close inspection of the board (from ggg) revealed one of the ground traces was cut as well as the trace to R1.  so I repaired those and now I get guitar signal thru the pedal, and the volume pot works, but gain knob seems to just change the corner frequency on some sort of filter that is again the same wooshing sound.  Also the tone pot works.  Any suggestions?
sorry I don't have voltages, still trying to figure out how to do that.

rove

... and I had the 5088's in backwards. but even after fixing that and a couple of grounding issues I still have the same problem.  The pots all seem to be doing their function except for the gain pot which simply spits out noise the frequency of which varies with the turning of the pot.  Guitar signal comes thru, but gain pot does not really affect it.
thanks for any help.

rove

Well I think the initial problem was the pcb.  I started over with a new pcb, made the pedal with no mods and it worked straight away like all the rest! Then I went in and applied most of the mods I originally intended, save for the boost switch and pot, maybe next time.  I particularly like the diode lift, aka comp cut, switch, as that is how I always use my bass drive. this was my first tonepad pcb and it was quite nice!
now, since I just got my breadboard, I am off to building the Vox Repeat Percussion.