Colorsound Power Boost - Custom PCB, Integrated Relay

MattG

Well-known member
Build Rating
5.00 star(s)
This is the fourth Colorsound Power Boost or Overdriver build I've done. First was the Aion Plasma (9v Overdriver), then the Aion Nucleus (18v Power Boost), then the Madbean MeatQlaw. As I mentioned in the MeatQlaw writeup, when applying the waterslide decal, I initially overlooked the fact that the PCB was designed for a 1590B enclosure, and applied the decal to a 125B. I always planned to go back and make my own Power Boost PCB for a 125B with the same potentiometer orientation as the MeatQlaw. I finally got around to doing just that!

In my two most recent builds (here and here), I used PedalPCB's simple non-latching relay bypass. I love the simplicity of this bypass (commodity parts and no microcontroller), and it gave me the ah-ha moment that it decouples the actual circuit switching from the mechanical foot switch. Meaning, if I'm going to make a custom PCB, I might as well integrate the relay bypass. This allows for less offboard wiring, use of the "premium feel" soft-switch SPST switches, shorter signal cabling within the pedal, and a single PCB.

I just finished the pedal last night, only had time for a quick sanity test. But it first up and worked right away. I did a quick side-by-side comparison to my MeatQlaw, sounds more or less the same (but with the added satisfaction of using my own PCB). I sprung for a black board and the ENIG finish. I think it's a nice looking PCB. This is of course the second revision, I mentioned the prototype build here.

On the PCB, the actual component layout doesn't have the nice symmetry of PedalPCB boards. My main goals were isolating functional areas and minimizing track lengths and vias. Looking at the board, the lower-left is the LT1054 boost converter circuit; this area has a deliberate break in the ground planes between it and the right hand side, which is is the actual Power Boost circuit. The top and upper-right are the main power supply and relay bypass circuits.

Clearly I'm enamored with this circuit. I've actually had somewhat of an on-again, off-again relationship with it. I've come to the conclusion that it does require a little tweaking to get just-right. But it's also super-versatile. It works as a straight clean boost, and/or EQ; it can be used as a decent fuzz; can have the role of a treble booster; it can sorta do the edge-of-breakup thing... all while sounding very "vintage". In the lower gain settings, at bedroom volumes, there is a noticeable "splatty" decay to the notes (plenty of discussion about this all over the net). I can see how it would be a turn-off to some. I've actually grown rather fond of it, as it gives the guitar tone a hint of old-mediocre-recording vibe, or, as I like to think of it, vintage mojo. Either way, those artifacts aren't noticeable at louder volumes and/or in a band mix. One of my favorite uses recently is stacked into my Barber Gain Changer clone: I have the GC set for low-gain, edge-of-breakup, and the Power Boost drive set high enough to be a little fuzzy. As these guys demonstrate, the Power Boost really shines, almost demands, an amp that's already louder-than-bedroom-level. But I find with the GC in between amp and Power Boost, I can get satisfyingly close to the cranked sound at family-friendly volumes. Although I haven't really tried with other pedals, I suspect any pedal that stacks well, is reasonably transparent, and does a good edge-of-breakup thing would work well in the GC's place.

I'm giving myself five stars for this one. I got a little sloppy with the off-board wiring at the end, I was in a hurry to finish, but otherwise I think it's one of my better builds. For my next self-made PCB, I'm going surface mount. I'm also flirting with the idea of doing a four-layer board (I've thus far only ever made two-layer boards). Surface mount almost becomes a necessity when you start cramming lots of features into the circuit (relay bypass, 18v boost converter, and switchable buffered bypass would be nice too!); but I'd also like to be able to do top-mount jacks in a 1590B enclosure.
 

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Great build!!! I'm a huge power boost fan... My Nucleus build with vintage components literally never leaves my board...
 
@MattG was this a one off board? Or did you get spares? I've been itching to build a Colorsound PowerBoost to continue my "Gilmour-ish" tone chasing. I'm waiting for the PPCB one to come back in stock but have also been toying with building out one of the Aion projects. Between the Plasma, Nucleus and MeatQlaw which would you recommend as most faithful representation of the PB?
 
I built an overdriver which I guess is really similar minus the charge pump for more headroom and it's one of my favorite pedals.
 
I built an overdriver which I guess is really similar minus the charge pump for more headroom and it's one of my favorite pedals.
I believe that's the difference between the Aion Plasma and Nucleus right? One has the charge pump?
 
@MattG was this a one off board? Or did you get spares? I've been itching to build a Colorsound PowerBoost to continue my "Gilmour-ish" tone chasing. I'm waiting for the PPCB one to come back in stock but have also been toying with building out one of the Aion projects. Between the Plasma, Nucleus and MeatQlaw which would you recommend as most faithful representation of the PB?

I have a few spares that I'm happy to give away. PM me if interested.

I believe that's the difference between the Aion Plasma and Nucleus right? One has the charge pump?

Certainly, one major difference between the Power Boost and Overdriver is 18v vs 9v, respectively.

However, it appears there are subtle circuit changes as well. I don't have the link handy, but there's a fairly long thread on freestompboxes discussing this family of pedals. In fact, it appears the 18v Power Boost actually had a circuit revision; this is mentioned in the FSB thread, and also in the build docs for the Aion Nucleus. So the FSB community consensus is that there are three total circuits (two for the 18v Power Boost, and one for the 9v Overdriver). IIRC, the topology across all three is essentially the same, just a few component values changed.
 
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They're here, I'm just waiting until Wednesday to add all of the new releases (there are quite a few) so I'm not completely overloaded with shipments when I get back.
in related matters, I just saw that the new ADHD is PCB543, which means you're only 12 more releases away from PCB555. PLEASE tell me that pcb number is being specifically reserved for that simple little 555 Atari punk drone synth board. 🤣
 
That's a great looking project. My little 6505 just HATES this pedal but I've never quiet given up on it. If memory serves (rarely anymore) I have the GuitarPCB version and the MB version. I have to think this thing would punish the input on a non-master volume amp like an old Marshall, Hiwatt, or a Traynor.
 
They're here, I'm just waiting until Wednesday to add all of the new releases (there are quite a few) so I'm not completely overloaded with shipments when I get back.
Dude. you been on a tear.......my credit card is trembling at the notion of when all these boards in my "waitlist" come back in stock.....I'ma gonna be screwed........ :ROFLMAO:
 
Your build inspires me to revisit this circuit...

... A long time ago I spent a lot of time looking into all the permutations of the originals (made charts/tables) and all the DIY versions I could find (more charts/tables) with the intention of being able to have one pedal and swap between the versions with a few toggles and a charge pump ... Alas, other matters became more pressing and I never finished my research.
 
Lovely build, and a reminder to me of the current state of board making. I can remember the last time (not even 10 years ago) that I needed a small run of boards, simple ones, needed for a project, and what getting them etched by a small custom house here in the SF Bay Area (granted, at least a 150% surcharge) cost me (really my client). I knew at the time of offshore vendors, but the timing etc. was still very fluid. It almost amazes me, how available this has become.
 
@Alan W - yes, at this point, I've had dozens of small/simple boards made (not just for guitar effect pedals), and I still sit and look at them in awe when I receive them. I started out using Elecrow, but switched to JLCPCB a few years back. For a small 2-layer board, it's $2 for five PCBs, or $5 for 10. Shipping costs more than the boards.

I read some commentary by the owner of OSHPark (maybe on Reddit?), he said it would be impossible to sell PCBs as cheap as the Chinese fabs. He suspects the cheap small-lot prices are loss leaders to attract the large scale customers, where the real money is.

Now, at least with JLCPCB, the dirt-cheap prices are only for the HASL finish. By comparison, OSHPark only does ENIG; ENIG is a pretty big premium with JLCPCB. So with a more apples-to-apples comparison, the price discrepancy actually narrows considerably. I plan to switch to OSHPark with my next PCB. (You can also direct submit KiCad files to OSHPark, without having to generate the Gerber files. Granted it's not hard to generate Gerbers, but it's an extra step that always worries me: trivial though it is, if not done right it can result in a bad board.)
 
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