Boss CS-3 Sava Mod

[Sava]

I'll describe some modifications that I've made on a Boss CS-3 pedal in order to improve it - hopefully it'll be of good use!

Some of the main problems that a stock CS-3 has are a huge amount of hiss and an audible "thinning" of the sound. Also, the highs are relatively "sterile". Most of my mods were dedicated to solving these problems.

  I've recently acquired another CS-3, and this revision has a THAT2189LC instead of THAT2159 which my old CS-3 has. (I'll leave out the THAT2159 revision mods out of this text.) Those two THAT chips should be virtually identical, however the THAT2189LC/equipped model had a bit more hiss and a bit less sustain, but also more "musical" sound altogether.



I alwazs stress the need for a good power-supply, since the power-supply can transfer a lot of "impurities" in the sound. Therefore I've replaced all of the resistors which transfer the current to active elements with metal-film equivalents, as they have significantly less noise level. I've switched R3, R25, R26, R27, R28, R2 and R7 on the main board and R1, R2, R3 and R4 on the potentiometer-board with metal films of the same value (nota bene, this THAT2189LC revision has a 3K9 for R4, and 1K5 for a R7). I've also replaced aluminium-electrolytic caps with tantalum caps, so that C1 is now 47uF/25V, and C3 is now 47uF/16V. These changes have drastically lowered the noise-level and allowed more radical sustain.

Eventually I've replaced C5 (originally a 560pF ceramic cap) in the IC2b's feedback-loop with a multi-layered 680pF cap. I suppose it would be even better if I've used a Silver Mica dielectric cap, however I didn't have any available at the time. These changes have produced a warmer, more "musical" tone, especially in highs. One could use a 820pF for a C5, however the higs would then seem too "soft".



You could listen to a sound-sample here:
http://www.box.net/shared/ujglu5sw08   (Intro is clean guitar)

Power supply: AC/DC converter 9V.

[Timebutt]

Wow great playing there!
I was wondering, I always thought the CS-3 would benefit the most by replacing components that are directly in the signal path instead of components related to the power supply part?
It would be interesting to have a soundclip that gives us an idea of 'before' and 'after', to effectively review the mod, I can't tell much about the 'improvement' of the CS-3, other than that it seems to be noisefree now ...

[ayayay!]

Hope you don't mind me tagging onto your thread.  I saw that box.net player and had to try it. 

Here's my CS-3 mod.  It's quite different from yours. SAD attempt to play a little bit of Another Brick In The Wall and some other fiddling.  This is direct.  I wasn't going for heavy squeeze.  Just curious to see how it sounded direct. 

http://www.box.net/shared/9v4i3kuos8

[Sava]

Wow great playing there!

Demo guitarist is my friend and excellent guitarist Duda Bezuha. About Duda visit http://www.myspace.com/dudabezuha and/or http://profile.myspace.com/index.cfm?fuseaction=user.viewprofile&friendID=113636154 or
http://www.zona-b.com/albumi.php.

It would be interesting to have a soundclip that gives us an idea of 'before' and 'after', to effectively review the mod, I can't tell much about the 'improvement' of the CS-3, other than that it seems to be noisefree now ...

I agree but now is too late.

[Sava]

Hope you don't mind me tagging onto your thread.  I saw that box.net player and had to try it. 

Here's my CS-3 mod.  It's quite different from yours. SAD attempt to play a little bit of Another Brick In The Wall and some other fiddling.  This is direct.  I wasn't going for heavy squeeze.  Just curious to see how it sounded direct. 

http://www.box.net/shared/9v4i3kuos8

Nice!
Regards,
Sava

[ayayay!]

Nice job to you too, Sava.

The CS-3 CAN be made into a great pedal, but sometimes it takes something new besides the same old tricks with modifying, wouldn't you agree?   

[dorothegreat]

hi sava!

and  almost a year later on this thread, i was just curious and wanted to ask you with regards to your SAVA mod 1 and 2.

i have a cs-3 and wanted to mod to REALLY lessen the noise, i use it before my dist and od peds, i wanted to use the cs-3 but with my gain at 2:00o'clock, my rig hiss A LOT.

just wanted to ask if both the mods (mod 1 and 2) would bring the noise level way way down with your mods.

regards!

[Sava]

My last update for MIT CS-3 ser. no. DU82006 with THAT 2181Lc:

1. For less noise
C1, C3, C8 = tantal cap
R2, R3, R28, R27, R7, R10 = metal film res
2. for sweeter and softer tone
R9, R6 = 12 KOhm
C5 = 1n5 ceramic cap