TS-808 Mod. Help

[TKS]

I would like to try a couple of mods to my 808RI.  I would like to mod the following:  The .047uF cap (bass mod), the 4.7K (high drive), the 51K (low drive) the .22uF (tone cap), and the 510K to 620K like keeley uses to raise the input impedence.  I am not sure which .22uf cap is the tone cap could you tell me if it is the upper or the lower one in the pic?  Also could you check the other parts to see if I have the correct part circled.  Thanks

[tcobretti]

I am not a tube screamer guy, but I feel I should tell you that it is somewhat unlikely that anybody here has that circuit board memorized to that degree (I guess it's possible...).  The best thing you can do is get a schematic for it and by comparing the schematic and the layout figure it out for yourself.  I am honestly not trying to be a jerk; it's just that based on what you have given us it would be pretty tough to help you out.

I hope I'm wrong and that somebody here has that layout memorized.

[darron]

dead easy. take a look at geofex's tubescream schematic:



as you can see the tone cap 0.22 that you are talking about comes right off the mid connection on the potentiometer... so follow the wire from the middle knob along the pcb and it will take you right to it.

[analog kid]

I believe I have it memorized pretty well but I think if you're knowledgable enough to read resistor codes then you can probably trace through the schematic with the board and verify these components yourself  )    I've modded a few screamers but my layout is also similar , there's not too many way's you can lay some of it out.
and I don't mind helping if I can at least on a couple things   seeing that it's probably (aside from maybe a fuzz face) the most known and beginner build or mod, no secrets here. I mean come on R.K. himself obvioulsy has no hope of keeping his mods to himself on this one since he lists them in all clarity

now I of course can't see the color code and you could have the wrong one there circled BUT i assume you're not circling a 51k R that's NOT a 51k)
it's the LOWER 22uf cap  you want to affect the low end of the tone control. Not the one tucked beside the opamp.

You have the right  4.7k and .047uf circled.  go as low as 2.4k for some wicked high TS gain. and 20somethingk for a good clean up.      raising the .047 will lower the frequency rolloff point
you want the 510k AT the input of the circuit obviously. SO just trace and make sure that's the one you're changing, there's only two components before it!!  raising the input impedance a bit may be helpful when not using a true bypass switching

[MartyMart]

I'm sad enough to know where those parts are ! ( well I've modified about 30 )
0.047 is labelled correctly, make this a 0.1 ... don't go bigger here or you'll have
"mud" in the overdriven sound.
Resistors are also correct
The 0.22 you want is the lower one, the one next to the opamp is to ground off pin 1
and this one I like as either a 0.1or a .047 for some more "air" is the TS sound
... IMO worth changing.
While you're in there, you could change the two light blue 1uf NP electros to poly's
though it's hard to get them small enough, WIMA make some that are thin and tall
(12mm) BUT ... they are about two bucks each !!

MM

BTW - if you're unsure about this, pull each resistor one at a time and quickly measure
it's value with a DMM .... then replace it  !
Just so you dont mix up the 51k and 510k for instance  !  easily done