Boss CS-3 Mods Part 3, Finding the right IC stack, last cap changes

Final part of the modifcation to Boss CS-3 compressor. Definitely worth the wait. Tayda order and guitarpedalparts order came in to finish this mod. I tried testing and stacking different IC chips, including TL062CP, TL072CP, RP4558P and OPA2134PA.

Results of IC Stacks:
The TL062CP and TL072CP were a bit noisy, stacked with each other and the RP4558P.
The RP4558P stacked with itself sounded pretty good, some noise
The OPA2134PA stacked with a RP4558P, the quietest one. Really sounds amazing with this combo. I can see why OPA2134PA is so expensive.

Last Cap changes
C1 100uF 16V 105C JRB Radial Electrolytic Capacitor 5x11mm SKU A-972
C8 4.7uF 35V 105C JRB Radial Electrolytic Capacitor 5x11mm SKU A-974
C3 47uf 10v same value, just replaced with from my shed, forgot to order a aluminum cap on Tayda

Totally pleased now with the modifications. Sounds so much better than stock, no noise or hiss, comparable to an optical compressor but with better punch. Yeah this is staying on my board as always on.

So if you are going to this mod, you can buy the Monte allums mod that changes both IC chips or you can just by his adaptor on Reverb and by your own IC chips. Or you can just replace all the caps to save money, that will take care of most of the noise. Totally can skip replacing all the resistors. Just did it for kicks. Wouldn’t say it improved noise. And the Diodes, definitely would change if you want something warmer.

This pedal builder from Australia is sending me a compressor he built. He shipped to me for free to test out, will definitely compare it to this. It has a release knob on it. All my changes listed below. Lol Boss should just release these mods as a waza craft compressor, you know they would sell a shitload.




Boss CS-3 Full component list, Capacitors, Diodes, Resistors swap Part 2.75

More Boss CS-3 mods. Replaced most all diodes with Germanium IN34As, didn’t notice really any difference. Replaced most all capacitors. I did notice that the ceramic capacitors that I pulled had values that were way off. Didn’t notice much of a difference until I stacked a Boss DS2 after it. The hiss was lowered slightly and can drive it a littler harder. Which is great because I love the DS2. My custom optical still performs cleaner as expected, but now I can run the CS-3 to get that punch that I love without the hiss and noise.

I also grabbed all the components for Boss CS-3 Services notes and noted all their original values and changes I made. I am going to order some electrolytic caps for C1 and C3 and OPA2134PA IC chip from Tayda, taydaelectronics.com, diy stompboxes recommends them. Their prices and inventory are pretty massive.


Part 2.5 Resistor swap changes
I changed all the 10k resistors with metal film ones. The resistors have a better tolerance. Can’t say it cleaned up noise, more like gave more clarity, will definitely replace the 28 remaining ones. So far so good, no dead solder joints. – After that I can try different values, maybe play with the attack resistor on the vr board a little bit, be cool if I can make it more punchy.

Part 2.75 Replaced all resistors with metallized ones, same values
Maybe a little more clarity but noise levels were not significantly improved.

Also worth of note is the pickup height on your guitar really alters the sustain and noise levels of compressor. My pickup height was too low and it grabbed more noise. I set up all my guitars at 1/16″ height on treble side and 1/8″ on bass side. I setup this height while depressing last fret. If both sides were set to same height, it sounds muddy to me, with bass strings dominating.

Way more headroom now and I can stack a compressor, overdrive and DS-2 distortion now without hiss. For humbuckers it is totally usable and improved noise with single coils, but for single coils the optical compressor is still has lower noise.

Overall I’m really happy with it now. The noise is tamed and I can now have 3 levels of gain staging before going to amp and the attack makes my single notes more articulated and punchy. The compressor alone can drive the amp a little bit when volume cranked, but no so much when stacking DS-2 distortion. But that may an issue solely on the DS2 noise, which I’ll probably tweak next with the Wampler mods. Think this pedal will stay on my board a long time. Going to do those last two capacitor swaps and IC chip mod just for kicks. Not bad for a 58 dollar investment, now it sounds amazing. Will do part 3 when tayda shipment arrives. Cya

Boss CS-3 Modifications, IC1 Chip, reduce noise and add some warmth -added Wampler pdf Part 1

Modified by Boss CS-3. Purchased on eBay for $58 dollars. Wanted something with good attack. I already own an clean optical one.
The noise on this thing was horrible, the tone lackluster, was not really usable for what I wanted, but it has awesome attack, super punchy!

Purchased the Monte Williams noise decimator kit because I wanted to keep the attack.

Researched and changes made
C4, C6, C14, C17- kept stock value of 1uf and swapped for Tantulum 1 uf caps. Made noticeable difference in noise. Measured the old ones and they were still up to spec.

C1 changed .027uf to .047uf– pretty tame modification some go all the way to over 1uf. This was a pain to get to. Monte said I didn’t have remove the mini pcb, but I did anyways. The struggle was real.

IC1 replaced with Brown Burr OPA2134PA
– The Monte Williams adaptor kit is ingenious, makes your life easier. It is a super tight fit. You must bend Q1 and C14 out of the way for it to fit. Also the wick for removing the solder was also really helpful. Noticed less noise for sure, but not as notable as just changing the caps. I think you can use the compressor after those first cap changes.

Diodes D2, D3, D6- Replaced with IN34A germanium diodes– This one gave it warmth, It can now drive my amp a little bit. Not as much as the JHS Pulp n Peel, more like a light overdrive. Before I could raise the volume and sustain but was crushed by noise. Now it usable like a drive effect. That combined with the attack I love.

Future mods- Possible replace the IC2 with adaptor from Monte and buy the chips somewhere and experiment stacking different ones. Links for information and where to buy below. C2 change and maybe replace all the resistors to metal film, keep default value, maybe get noise a little lower?

Where to buy
https://www.monteallums.com/pedal_mods_CS3.html Monte’s CS3 Mods
https://reverb.com/item/950068-boss-dual-stack-chip-adapter-mod-kit Monte Adaptor kit, can stack them!
https://www.ebay.com/itm/122108576789 IN34A Germanium diodes, same ones I purchased.
https://www.ebay.com/itm/261992568237 Some BURR-BROWN OPA2134PA, haven’t bought these yet, will buy when I make future mods and with the adaptor kit Monte sells on reverb.
https://www.ebay.com/itm/274700650976 Same 1uf Tantalum polarized caps I used.
https://www.amazon.com/How-Modify-Guitar-Pedals-how/dp/1434801063 Wamplers book, more in depth than beginner guide below

Information for more mods I found
http://www.lonephantom.com/2010/03/modding-the-boss-cs-3/
https://www.zeta-sound.se/Temp/CS3-mods.pdf
https://www.tdpri.com/threads/boss-cs-3-power-problem.328985/
https://www.tdpri.com/threads/quieting-a-cs3-compressor.173259/
https://www.tdpri.com/threads/my-mods-of-boss-cs-3-nice-pedal-now.957360/
https://www.ultimate-guitar.com/forum/showthread.php?t=1068026k
https://www.diystompboxes.com/smfforum/index.php?topic=68796.0
https://www.thegearpage.net/board/index.php?threads/opinions-on-boss-cs-3-mods.1675905/
https://www.diystompboxes.com/smfforum/index.php?topic=58324.0
https://www.freestompboxes.org/viewtopic.php?t=6038
http://www.ovnilab.com/articles/cs3modding.shtml

Tips for Noobs
Use the wick Monte gives you to remove all the solder. This made removing the IC1 chip a breeze. Also don’t force it out, the part should slide out easily. I tore one cap pad buy doing this. Tried a solder sucker at first but it is just so awkward using one and it doesn’t always work at first, definitely a skill I haven’t mastered.

Use flux every time- just do it, finally got into the habit of doing this every time I use solder something. Don’t run the hassle of making cold joints, it’s a pain to troubleshoot. Solder flows way better, I’ve ruined so many guitar pots by overheating them.

Clean tip with flux after finish using. So far I’ve had the same tips for 10 years. no joke.

Use Digital Multimeter to check and troubleshoot continuity. I also test capacitors and resistors when replacing them and tested old ones too.

Document your changes, you may want to revert back. I test after replacing a handful of components, not every single one, that’s just tarded.

Wampler beginner guide below, more in depth guide he sells on … Read the rest