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Sure. The only consideration is space. Most of the caps are 5mm lead spacing, but a few are 2.5mm. You can use any film or ceramic cap that will fit on the tiny board.

Dang, that's a neat idea!

Since the MBP sitcker has been out of stock for a bit I've added a small new piece of swag: the MBP Pick of Killer Riffage. Known to cause finger melting and female swooning. Use with caution.



The pick is .96mm thick and made of celluloid material. Screening is pretty good, although I have not put it through sweaty palms yet to see if it will rub off. But, it's a mere $.75 so what more can I do?

That is outstanding!

I think this is a good idea that can be simplified a whole lot without compromising it tone-wise.

If you are open to suggestions this is what I would do if I were designing this.

Drop the entire input buffer and replace it with the output section.
Move the tone section to right after the drive section.
Move IC1A to directly after the tone section. Make R11 and R15 a small value--anything between 3k3-10k (they should be the same value or R11 a little higher to increase output). Tie R15 directly to Vb, NOT the non-inverted input.
Use a high value decoupling cap at the output of that stage and then a Volume control directly after it.

So, the overall order would be:
JFET input  - gain stage - TMB controls - recovery stage - output.

The reason I'm suggesting this is that IC1A is superfluous as you have it drawn. You do not need any kind of gain or tone shaping stage between IC1B and the TMB controls. But, you do need a recovery stage after the TMB and since you already have a free amp, it makes more sense to put it there than the JFET stage. However, the JFET input is another thing to set it apart from other designs. Plus, it will "cook" the input a little. You might want to increase the value of R5 a bit if you do this, but I'm not sure.

One alternative idea: drop the input and go straight into IC1B, leave the JFET at the output and make IC1A a buffer for Vb instead.

Anyway, take these suggestions with a grain of salt. Your ears are the best decision makers, of course Keep it up!!

This is basically the same thing: http://www.madbeanpedals.com/forum/index.php?topic=1661.msg36328#msg36328

And here is the stuff: http://www.madbeanpedals.com/forum/index.php?action=dlattach;topic=1661.0;attach=3277

From what I gather from the gut shot I saw, the bass trimmer is done in conjunction with a 68n cap in the second stage of the op-amp. Take a look at the "Sparkplug" schematic and you will see a method to do this. You would need to remove C4 and R6 from the Egghead PCB and wire the pads to a bit of perf or vero, then integrate the bass control on there as well. So, it would be two caps in series and a resistor and trimmer in series, then the junction of the two caps connects to the junction of the resistor and trimmer.

Ha ha....you look like an easy natured d00d! Randy Quaid, OTOH, is a bit of a nut.

Looks great! You have indeed conquered the most difficult project here 

Follow the procedure outlined in the doc. You should get about 500-550 ms of delay. It's a matter of adjusting the bias and gain trimmers to get a strong signal through there.

D1 does not need a CLR. As you turn the Level pot up the signal will start to break up and light up the LED. If is still not lighting, please make sure you have installed it in the correct way and used a 2n5087 or similar PNP transistor for Q1.

It's pin13 on a 14 pin package, but I call it pin7 on the schematic since there are only 8 pins total for the IC. Anyway, that's signal in.

So, what should happen is the delayed signal out on pins 3 and 4 (or 6 and 7 if you prefer) but the BIAS trimmer has to be set correctly for that output to occur. Do you get any audio out of those pins in any turn of the BIAS1 pot?

No signal to pin7 of IC4 (the first BBD)?

I'm guessing C4, R8 and D1 can be left off and D2 can be jumpered.

Maybe also omit R10, R11 and merge C5 and C6?

Yes to the first part. For the second part, you probably need to leave off R11 and just jumper C6.

I probably did not explain Path very well in the build doc. What it does is create a signal path between the delay output and dry/wet mixer that bypasses the filtering. This means your first repeat is essentially unfiltered. However, that first repeat DOES go through the filtering and gets sent back to the delay input. So, the overall effect is to lessen the degree to which the filtering acts at during the very first half dozen repeats or so. See the illustration below.

To hear it: try setting it to Tape, set the Delay around 500ms and FDBK to long repeats but before it self -oscillates. Now listen to Path on and off. Pay particular attention to the difference in tone in the first half dozen or so repeats. It's subtle, but definitely there.

Here's the post I just made in the errata section: http://www.madbeanpedals.com/forum/index.php?topic=8451.0

Thanks for bringing this to my attention.