Boss ROD-10 - schematic

[Mark Hammer]

Just back from a quick trip out over lunch and I happened onto a Boss ROD-10 unit for $49, so I picked it up.  This is a half-rack unit from the late 1980's with 4 different overdrives and a fuzz, plus 3-band semi-parametric EQ and remote switching.  The circuits are largely discrete, and a couple fairly similar to the overall topography of the BD-2.  I have the schematic at home but was looking to have something to peruse on the way home.  I know the schematic is posted somewhere, but I can't seem to find it, either by searching here or on Google.

Can anyone help me out?

[Arn C.]

Hey Mark!

email me with your email to arn.conklin@ametek.com and I wil send you about 2 megs worth of stuff on this!

Peace!
Arn C.

[Mark Hammer]

Look for it  And thanks

[Arn C.]

You've got mail !!!!

You are welcome Mark!

Peace!
Arn C.

[Mark Hammer]

Thank you, sir.  You are a scholar and a gentleman.

[Mark Hammer]

So, I tried it out last night, schematic in hand.  Interesting unit that tries to span the gamut from slightly-coloured booster to  BD-2/Bad-Monkey territory to more serious distortion.  Ironically, none of the 5 different distortions really seems to have a distinctive personality.  On the other hand, there is ample room for modding this thing or for trying out mods which may be appropriate for inserting into other pedals.  The "distortion" channel appears to be VERY similar to the BD-2, except with the clipping diodes inserted after the second discrete op-amp, rather than after the first one. Missing also is the extensive tone-shaping between stages that is found on the BD-2.  Finally, where gain is adjusted in both discrete op-amps simultaneously in the BD-2, here the gain is only adjusted in the 2nd op-amp.

One of the quirks of the ROD-10 is that it uses a single quad-ganged 250k pot to control gain in 4 of the 5 sub-circuits.  What about the 5th?  That's the "fuzz" which takes its feed from the output of the first and least distorted OD circuit, such that the gain of overdrive 1 sets how hard the fuzz circuit is pushed.  The fuzz circuit, meanwhile, seems like a kind of wimped-out octave-up fuzz, in the same general category as the Foxx, Superfuzz, fender Blender, etc., except without the diodes that facilitate frequency doubling.  I think I may do some experimenting there.

Here's a trimmed down PNG version of the schematic.  Many thanks to Arn for this. http://img.photobucket.com/albums/v474/mhammer/ROD-10.png    Please note there is an error on the factory schem.  Those with a sharp eye will note that the input at the switching FET for the Fuzz channel seems to be the D16 diode on the gate of another switching FET.  Clearly this makes no sense.  The factory-issued correction to this indicates that in fact Q42 takes its feed from the output of the OD1 at the output of Q30, just after C62 (1uf).

Jay Doyle, if you're reading this, the ROD-10 is really and truly a playground for you.