Catalinbread Varioboost - Custom SMD PCB, 1590B Top Mount Jacks

[MattG]

Build Rating

5.00 star(s)

Here's my latest spin of the Catalinbread Varioboost circuit. My gateway to this circuit was the PedalPCB Mercurial Boost. I then made my own custom PCB of the circuit, with integrated relay bypass, and all three knobs on the same horizontal line.

Now I took it a step further and shrunk it down by going with a surface-mount design. This allowed me to fit the circuit into a 1590B enclosure with top-mount jacks. Credit to @MichaelW for his 1590B Top Mounted Jacks Guide. (Only when I took the picture did I realize my I/O jacks aren't straight!)

Not a lot to say about this circuit that hasn't already been said. It's kinda-sorta a one-band parametric EQ. It's a very swiss-army-knife kind of pedal. I use it as a lead boost.

I had JLCPCB fabricate the board and do the SMD assembly. Everything worked on first power-up! My only build issue was that I habitually use pre-cut lengths of wire for going between the I/O jacks and the PCB. And the wires I used were just a wee bit too short. And of course I realized this after I put a blob of hot-melt glue where the wires mate to the PCB. So I had to splice a length of wire in. Easy but tedious fix.

The enclosure is one of my favorites, "Weston Grey" from @StompBoxParts (link). The graphics are Sunnyscopa film-free waterslide decal. This time around, I had pretty much perfect transfer of the toner. I did pre-wipe the enclosure with acetone before applying the decal. The graphic is the "Guardian" from Zelda. I've used this before, I think it looks great on the Weston Grey. I've sold all my previous pedals that used this graphic, and this Varioboost I plan on keeping!

I have a few spares of the assembled SMD PCBs, if anyone is interested in one, PM me.

 

[iamjackslackof]

Very nicely done!

What relay bypass scheme are you using? I see on some of your other builds you use it as well. I've not seen one that uses what seems to be an analog mux/demux?

 

[MattG]

What relay bypass scheme are you using? I see on some of your other builds you use it as well. I've not seen one that uses what seems to be an analog mux/demux?

In this build, it's a relay bypass scheme. A Panasonic TQ-2L-5V relay does the actual effect/bypass switching (meaning, mechanical i.e. true bypass). A cd40106 (cmos hex inverter) responds to the footswitch and maintains state. Only two of the six inverters are used. This IC is a current production commodity (cheap) part. It has Schmitt trigger inputs, which debounces the switch (and also provides a modicum of EMI protection against false switch presses). It uses very little power (micro amp current draw).

In other builds, I often use a buffered, electrical bypass scheme, details here: Buffered Electrical Bypass Module. That uses a CD4053 IC for the effect-bypass switching (so, not "true" bypass). It is functionally very similar to the buffered bypass scheme found in most Boss pedals (though I use ICs, Boss uses discrete components).

 

[MattG]

Build #2 turned out a little cleaner overall I think.

I initially got away from top-mount 1590B builds, because the I/O jacks are too close together for the patch cables I was using with the pancake-style connectors. I never found any "mini" cables that worked reliably or inspired confidence. But now this World's Best Cables (WBC) brand is making short patch cables with the Eminence Tiny connectors (amazon link), and so far I've had good luck with them, and they are small enough to use with 1590B top-mount jack builds.