PedalPCB Brown Betty with voicing switch (Brown Betty/Dirty Sanchez/Thermionic)

[lowpitch]

Build Rating

5.00 star(s)

So I built a Brown Betty and since I hate commitment I added a switch to toggle between Brown Betty, Dirty Sanchez and Thermionic Deluxe specs. I had some concerns that the wiring to the switch would add significant noise but it turned out fine.
Two resistors (or trimpots if I can fit them) are still missing on the vero. The way it's wired up these will go in parallel with the trimpot on the PCB. So by adjusting the resistors/trimmers on the vero I can get two additional switchable gain settings. I haven't decided on values yet so I left those unpopulated.

Edit: I updated the vero layout with the values I settled on for the alternate trimpot settings. I measured the trimpot on the PCB at 43K which is my Dirty Sanchez setting. Alternate settings translate to 40K for Thermionic and 35K for Brown Betty.

The build was pretty smooth, even the switch wiring. Of course I had to trip at the finish line and bungled the DC jack wiring. Woopsie... Fortunately no harm done though. Reversed the wiring and everything worked perfectly.

The Dirty Sanchez has a tight switch instead of a pot but I did not bother including that. My DMM says tight pot at 10 o' clock = DS tight switch off and tight pot at 12 o' clock = DS tight switch on. Other than that there's only one cap difference between the Dirty Sanchez and the Brown Betty and they do sound very similar, the latter being just a tad darker/smoother. I still think having the two on a switch will eventually be useful once I put the resistors on the vero for switchable gain trimpot settings.
The Thermionic is a different beast of course. So much more gain on tap, very aggressive hard clipping. It's a little too much for me to be honest. No sound clips yet but I will be doing a full demo video in a couple of days.

I'm not totally happy with the enclosure design. The corner radii are off and the print turned out way more yellow than anticipated - was supposed to be that beige/gold color of the Friedman pedals. It still looks decent but it could have been better. Oh well. I still got another Brown Betty board so I guess I'll fix it in round two

 

[Brett]

I think the enclosure's UV design looks great and your off-board vero is tidy. I understand that space is limited in the enclosure, but can you confidently activate the pedal without worrying about accidentally stepping on the rotary switch?

 

[lowpitch]

I think the enclosure's UV design looks great and your off-board vero is tidy. I understand that space is limited in the enclosure, but can you confidently activate the pedal without worrying about accidentally stepping on the rotary switch?

Good point. Nope, requires some decent aim for sure. Goes on my to do list for V2, side mounted voicing switch!

 

[Synchrony Pedalworks]

Great build!

 

[Chuck D. Bones]

Nice work!
Did you try breadboarding it first?

 

[lowpitch]

Nice work!
Did you try breadboarding it first?

Thanks! Nope, but I should really start doing that. Would take the guesswork out of mods and whatever before committing to something more permanent.

 

[jcpst]

Very cool- love the concept. I like the use of a rotary switch too.

If you're doing a round two, and were willing to forgo PCB mounting the TMB pots, you could do two rows of four and get that rotary knob up with the other controls.

 

[lowpitch]

Very cool- love the concept. I like the use of a rotary switch too.

If you're doing a round two, and were willing to forgo PCB mounting the TMB pots, you could do two rows of four and get that rotary knob up with the other controls.

I like that idea!

 

[Bucksears]

Sorry to derail, but what is different about the Brown Betty vs the Dirty Sanchez & Thermionic?
I thought the BB was just a layout that could accomodate the DS or the Thermionic (or mixture of both)?
i.e. I thought the BB isn't a unique circuit

The rotary is a cool idea, though. Love options on toggles.

 

[lowpitch]

Sorry to derail, but what is different about the Brown Betty vs the Dirty Sanchez & Thermionic?
I thought the BB was just a layout that could accomodate the DS or the Thermionic (or mixture of both)?
i.e. I thought the BB isn't a unique circuit

The rotary is a cool idea, though. Love options on toggles.

Brown Betty, Dirty Sanchez, Thermionic and Complex OD all share the same basic layout and you could build them all on a Brown Betty board pretty much. It's just a couple of capacitor and resistor values that differ between them. Also, the Dirty Sanchez has no tight pot but a tight switch, Thermionic lacks a mid control while the Thermionic Deluxe has one, Complex OD has a structure switch which lowers the effective gain pot value. The Brown Betty is more or less a Dirty Sanchez with an added tight pot and a higher value capacitor in the soft clipping arrangement.

 

[spi]

That's a great idea, but I'm curious if there's any noticeable differences between them that a slight twist of a knob doesn't make?

 

[lowpitch]

That's a great idea, but I'm curious if there's any noticeable differences between them that a slight twist of a knob doesn't make?

Between Dirty Sanchez and Brown Betty, no. They're close. The Thermionic is inherently brighter though and you won't get the same ratio between soft and hard clipping even with the trimpot dimed on the other circuits.