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Those are all silicon transistors. The 2N1308 is a germanium transistor. Those silicon transistors may work in this circuit (or they may not), but they will not sound the same as germanium. Amplified Parts sells 2N1308s, as do some eBay sellers. Other than the CV7351 (which is just a British...

It’s possible that there is DC that’s making them blink. Try putting a large capacitor between them and the rest of the signal path and see if they still pulse. Gotcha. I use V- or DC- for that pad on my schematics. It might be worth changing the name because the negative connection is 0v, not...

Congrats on making the leap! A few thoughts/questions: I'd recommend changing the polarity protection diode to a series diode, rather than the parallel diode to ground. A series diode is more reliable. I'm not sure if I'm reading the symbols correctly, but it also looks like your indicator LED...

SD-1 into a JCM-800 is one of my favorite amp/pedal combinations.

Those are Chinese 3AX31C germanium PNP transistors. The gain/leakage values that you measured are typical for the 3AX31C. I’ve used them in a few builds and they’ve worked well.

Could be a two transistor Darlington-type configuration for Q1, like the Tone Bender Mk. III.

Initial draft of the board is done. I'm still working on the artwork, so there might be some changes to the board depending on how that goes, but here's what I have at the moment:

No idea if PedalPCB plans on making a board, but in the meantime you’re right that it’s not very difficult to build one of these on a Trumpeter board. All the information that you need has already been posted in this thread, so feel free to get building if you’re so inclined!

I don’t know if @Robert has any plans, but I’m in the process of laying out a PCB and should have something ready for fabrication in the next week or so. I’ll keep you posted. I verified it using transistors with very similar specs to the ones in your unit: NPN Silicon - BC550B, hFE 425 NPN...

Either that or to confuse people like us. The 150k resistor has a ±5% tolerance, so anything less than 7.5k is within the margin of error. The version on my breadboard sounds exactly like the demos, so I’m pretty sure we’ve got this one right. Thank you again for the pics and measurements!

So I breadboarded the Rotobone, and you're 100% correct. Reversing the PNP transistor eliminates a lot of the unpleasant low end oscillation and gives much more intense trumpet tones. So with that, I think we've got a final schematic!

Nope, quite clear and easy to follow. I'll try it out on the breadboard tomorrow and see what happens if the PNP transistor is run with the emitter connected to ground.

I've had the same experience with the gray on the Royal Ohm brand of resistors. Spent way too much time trying to figure out where the 140k resistor on my breadboard came from before realizing that it was a gray stripe and a 180k. Basically, a PNP transistor needs to be flipped relative to an...

Both of those make sense to me and match the circuit for the Bone Machine/Mini Bone. Hmm, this seems off to me. The Bone Machine and Mini Bone have R4 = 560k; R5 = 150k; and R7 = 18k (using my schematic's designations). So does the Jordan Bosstone, which is the starting point for the Bone...

Comparing this schematic with the Trumpeter/Mini-Bone, I think that it's interesting that he changed the value of R7 (it was 18k in the Mini Bone/Bone Machine) and removed the 47pf capacitor that was in parallel with R7. I'm guessing that the reduced gain from a lower collector resistor...

Awesome work! Thank you so much for the detailed measurements. I have a few questions, and a draft schematic. Do you mean that these switch the input and output caps? I didn't see any capacitors in parallel with the capacitors on the switches in the pictures. I'm assuming that this 1n cap...

I've used wire from this 10 color set from Remington Industries in all of my builds over the last two years, and it's been great.

You should post pictures. Otherwise we don’t have any way of helping you.