How to refine the Son of Screamer ?

[HOTTUBES]

So if you lower R4 to 1 k , and increase  C4 to .1uf or .15 uf , the gain will increase , but the tone will stay pretty close to the same as it was ?

You mean C2, yeah?

Changing C2 to 220n, if you drop R4 to 1k, will give pretty much exact same frequency as before. (resistor and cap values follow the same ratios where ever they are on the series - roughly - so 4k7 -> 1k is four steps on the E6 series, so go up four steps on the E6 series for the cap)

C5 and R7 , do they play any role in this affair at all ?

Yes. Like I said, Boss used this circuit but changed a few things, maybe the most significant was the tone control component values. It's somewhat involved so I seriously suggest you read RG's article. Ignore the parts about buffers and switching and just read the clipping and tone/volume sections, and the mod and clone sections, where you will find a schematic of the son of screamer.

If you want SD-1 tone control, change C5 to 27n if you can find it, and R7 to 470R. probably easier to use 22n and 560R. C4 to 18n (again if you can get it) and R6 to 10k. or you could try 8K2 and 22n for easier values to find. Also, for SD-1 sound, leave C2 and R4 alone, but change the gain pot to 1M. Remove C3. Change R8 to 10k and try to fit a 10n in parallel with it. Try and fit two diodes in series for one of the diodes. Or use an LED which has about twice the forward voltage of a silicon signal diode, like IR or maybe red.

@#$% !! you rock man !!!!

Thanks so much !!!!!!

[HOTTUBES]

Wow , this is a great read , a little above my knowledge for the most part , but i did catch on to alot of it ....

That R.G. knows his Shit !!!



http://www.geofex.com/Article_Folders/TStech/tsxfram.htm

[Ben N]

 

[HOTTUBES]

I have built this SOS many times now , and i still can not get the SOS to sound like a modified version of a Boss SD1 !

I have subbed out just about every possible combo of caps , resistors , & diodes to no avail ....

Anyone have any tips or tricks they would care to share ??