Started by DrAlx, May 27, 2014, 05:26:49 AM

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What's better for a BBD pedal than a BBDD enclosure?

"NOT FLAMMABLE" is not a challenge


Quote from: Fender3D on July 26, 2014, 08:56:34 AM
What's better for a BBD pedal than a BBDD enclosure?

A bucket?   :D
Ohm's Law - much like Coles Law, but with less cabbage...


I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)


Larry kindly tested a print out of the PCB pdfs and measured the track separation and found it too small if using the toner transfer method.
I didn't account for the thickness of the graphics pen that drew the PCB pictures  :-[
I have now modified the PDFs and re-done the upload.
They should have a track separation of about 0.025 inches now.
The links are the same as before.

Here are the "Heavy PCB" pdfs

Here are the "Light PCB" pdfs



That was quick!

I printed the board file and checked it.....looks great!

I ordered parts yesterday so...time permitting, I'll get on this as soon as they arrive.
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)


Here is a link to Larry's component overlay for the "heavy" build.

I'll update the build instructions at some point with equivalent pictures for the other builds.


Quote from: puretube on June 25, 2014, 02:38:50 PM
That one glitch you don`t cancel at the output of the first of a few cascaded BBDs,
will ride on top of the audio into the next one and appear delayed at the output of that one. Now cancel that...
(or will it be that synchronized that it really does disappear by balancing that last BBD only?)

And how about the accumulating variable DC-pedestal?

More details to be found in BBD-related patents...

BTW.: tube-filament supply can be grounded on either side,
or centered fix,
or may be balanced with an anti-hummer pot - it all worx...   :icon_wink:

Fig.1 unveils the long hidden secret of the Memo-Man...


Zombie thread, resurrected!!! Again!!

Hi everyone,
I came across this thread a few months ago and this project looked really interesting to me so I decided to build one. Many thanks to Dr Alx for bringing this to everyone here!
I just finished calibrating it today and this is a really nice Flanger. Calibrating this is fairly straight forward but it helps that I've been working with and calibrating a lot of flanger projects lately, so I kind of know how these things work. Practice makes perfect, I guess! Lol!
This flanger works as two delay lines, the control voltage of one goes from about 1 volt to 6.5 volts and the other's goes from about 1 to 2 volts. I still need to measure the frequency sweeps of both delay lines, but it looks like one does a wide sweep while the other hovers around the upper end of the frequency sweep.
How does it sound??? Really good! Adjusting the offset, I can get the zero part of the flange to just hang there for a bit before it sweeps back down. Really cool!
There's 3 knobs, one is for the speed of the sweep, one for the width of the sweep and the last one for regeneration/feedback. All the feedback knob does is make the flanger sound metallic so I don't use it much, which is ok because I find that through zero flangers don't really need feedback to sound good.
I'm in the process of painting the box, so it will be a few days before it's boxed up. I managed to fit this in a 1590C enclosure.
Thanks again for making this one available!


Very good, has anyone heard from Larry, I hope he's safe and well.
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".


Hi everyone!
Hopefully Dr Alx sees this but I was bored today and decided to add an expression pedal function to this project. I'd also like to add that for a dual BBD project that this thing has NO clock heterodyne noise which I think is amazing because that is a very hard thing to achieve.
Anyway, I noticed that on the non-inverting input of the LM324 (pin 12) of my build the voltage varied from +3.199 volts to +4.171 volts. I came up with a simple circuit to be able to implement an expression pedal (10k ohms) for use with this, see attached picture. Basically, it's an LM317 circuit with 2 adjustment trimmers. One is to adjust voltage output of the LM317 and the other is to dial in the +3.199 volts on the low end of the expression pedal position.

The "ring switch" of the exp jack goes to R41 (4.7k) resistor end closest to pin 12 of the LM324, and the "ring" of the exp jack goes to pin 12 of the LM324. Works great!
Here's another photo to better clarify how I modified the board.


Does anyone have live links for this build that work? I went through and didn't see any that worked.



Thank you so much!  What a great project, Nice work sir!



would like to hear clips on these. previous links are dead.
BE d Bezt, Urz D Rezt... RoCk ON!!!


Quote from: rx5 on September 22, 2021, 08:57:56 AM

would like to hear clips on these. previous links are dead.
All those SoundCloud links in the first post still appear to work.


Quote from: DrAlx on September 22, 2021, 08:55:06 PM
Quote from: rx5 on September 22, 2021, 08:57:56 AM

would like to hear clips on these. previous links are dead.
All those SoundCloud links in the first post still appear to work.

ohh it was working!  :icon_mrgreen:

guess I had too much coffee already.

anyways ive been thinking about how I would do near/thru zero flanging with the mistress.. my initial take on this was having a static delay of 400uS + signal inversion on the dry line.. I guess its not enough?

so I again have to do another circuit with adjustable 'cancel phase'...
BE d Bezt, Urz D Rezt... RoCk ON!!!


Yes static delay plus inversion is the general idea but there are some things to watch out for.

1) Clock on a 3207 based mistress clone gives minimum delay higher than 400us. Not sure if clock on an original deluxe EM goes to delays that short. So you need a larger fixed delay than 400us I think.
2) The minimum delay in the EM sweep varies with range and rate pot settings.  So the fixed delay should be controllable with a pot.
3) The fixed delay should replace the "dry" arm of the EM flanger rather than be combined with the EM output. See send/receive connections in Madbean Current Lover EM clone schematic.
4) Depending on which EM/clone you have, you will find some signals are attenuated more than others by the BBD + associated circuitry, so to get perfect cancellation you need your fixed delay path to have matching frequency response to the variable delay path in the EM.
5) Heterodyne noise (or rather aliasing noise) if using another BBD for fixed delay.  Most important thing to do is not have any direct connection between BBD inputs,  and give each BBD it's own LPF on it's input pin. So your EM could need modding too if you want no whistles and chirps.


Hi. yes -static- delay. just using opamps here. max 400uS for a quad chip. I guess its still too low(or too high) a delay for mixxing with the wet signal.

1) Im using mixxed 'blocks' of EM. best sounding audio path + best LFO + buffered out(ala madbean) + some moJo  :icon_mrgreen:

its using MN3007 on 12v. as per datasheet recommends. more headroom. better sounding than with 9v supply(with a retweak of bbd bias)

2) agree. a variable delay should be better I guess.

3) yes thats what ive done. have mine wired with a small switch to select live dry & delayed dry

4) I guess the 13k(dry) and 8k2(wet) is good enough

5) regarding those, good layout should be done. as much as possible star grounding. all my diy pedals(from 2020) are done on veroboard/protoboard. my own layout. Ive learned a lot especially with building high gain pedals. havent done any dual BBDs until now..

below is a scope shot on the daughterboard ive done with the 'delay' dry. yellow =input from sig gen. blue =phase lag prior to inversion. purple =inverted out. all at unity gain. its a bit noisy, naked board.

hopefully my next ckt would some better(?) nzf/tzf.. your circuit looks like the dry delay 'tracks' the wet delay. better LFO too , not relying on RC elements for sine shaping. Id try that sometime too. on another modern flanger build. im just concerned if I could still get hold of MN BBDs. I only have a couple here. dont wanna mess my EM  ;)

BE d Bezt, Urz D Rezt... RoCk ON!!!


Yes, both BBDs are sweeping when this flanger is powered on. One BBD "sweeps" from around 550-920kHz. While the other BBD "sweeps" from 55-920kHz on my unit... So, what is happening is that the "dry" delay sweeps from 0.93ms to 0.56ms while the "variable" BBD sweeps from 9.3ms to 0.56ms. Both sweep in the same direction (same LFO) but they never cross, they only meet or "touch" at the high end of the sweep. A really neat design.


Gerber files for a 2-layer PCB of the "Heavy Build" described in the build instructions can be downloaded from here:!AvrH61utWEtEjlbFpZZNFDZHRFXo?e=v4Nq28

I got rid of the jumpers and moved D4 and D6 so they are not under ICs.