Hello folks!
Here's one that I made for me for a bit of fun. I have always thought the Square wave fuzz on the MicroSynth was a really cool thing, and this secures that for me. I added a filter to the output to be able to dial in the sound - its not the MS filter itself, but does a good approximation of the static cut off filter you can make with the Start/Stop sliders on a MS set at the same place.
It shines for things like the Smashing Pumpkins Siamese Dream era solo sounds where its an octave up and gnarly fuzz, and having the clean signal means you can stack fuzzes too. Also, its not my exact cup of tea but it cops a lot of that John Mayer thing where he had a really cool lofi fuzz solo tone on some live cuts.
(https://cdn.shopify.com/s/files/1/0956/3019/7077/files/IMG_1999.jpg?v=1758498632)
(https://cdn.shopify.com/s/files/1/0956/3019/7077/files/IMG_2048.jpg?v=1758498632)
Just so I dont forget
BOM:
https://docs.google.com/document/d/1Xa0SL2IED0Ec2r6M2_xnSVBZJqhK4pIk/edit?usp=drive_link&ouid=110218901478219288973&rtpof=true&sd=true
TAYDA Drill setup
https://drill.taydakits.com/box-designs/new?public_key=TjIxWFRCeUpET1N3Sm9ldmxhOFh4UT09Cg==
That looks great! Did you use an LM13700 for the OTA? I tried breadboarding this circuit years ago, but never really got a consistent sound out of it. Would love to hear a sound clip.
Very nicely done.
Looks incredible!
Are you gonna sell PCBs?
Quote from: lars on September 23, 2025, 12:44:46 AMThat looks great! Did you use an LM13700 for the OTA? I tried breadboarding this circuit years ago, but never really got a consistent sound out of it. Would love to hear a sound clip.
Yes its the LM13700 through hole.
It sounds great. What were you struggling with, sound wise?
Very vice indeed!
Looks great! What kind of filter topology did you end up using?
Quote from: Aleph Null on September 23, 2025, 03:39:10 PMLooks great! What kind of filter topology did you end up using?
I breadboarded the one out of your comparator fuzz, as it seemed to have that nice resonant peak, and being a LP filter was what I was after. Worked pretty great, minor changes only. thanks
Cool! I actually took that topology from the PT2399 datasheet. The first adjustable version a ever saw was the Noise control of the Hamlet delay.
Yeah its a nice little option for a LPF
Quote from: BricksnBeatles on September 23, 2025, 02:06:26 AMLooks incredible!
Are you gonna sell PCBs?
I wasnt planning to do so. Im not sure there would be demand anyway.
I'd be down for a board!
Quote from: LaceSensor on September 25, 2025, 10:03:46 AMI wasnt planning to do so. Im not sure there would be demand anyway.
I believe you have underestimated the sneakiness...
The microsynth fuzz sound is right up there with the Big Muff and the Fuzztain, because we're all trying to sound like Hummer anyway...
I would also be interested in purchasing a board! :D
I would probably pick up a board as well, though I haven't built anything for a long time.
Im debating selling some spare PCBs from the run.
I wouldnt be providing a full build doc, moreso a basic BOM and a drill template for Tayda drilling.
The PCBs were fabbed with 2 daughter PCB boards for 3PDT true bypass (you only need one, so there is a spare).
I would like to ask £12 GBP for each of these, shipped worldwide. Drop me a line at info@gigaheartsfx.com if this sounds reasonable
here is a proper janky demo on a bass, side by side a real EHX big box BMS - I think they sound remarkably similar if not identical.
The filter is a tad lossy; there is a trim pot on board to balance the outputs when engaged vs disengaged.
(https://cdn.shopify.com/s/files/1/0956/3019/7077/files/ms_pcb.jpg?v=1760014764)
Quote from: LaceSensor on October 09, 2025, 12:51:17 PMIm debating selling some spare PCBs from the run.
I wouldnt be providing a full build doc, moreso a basic BOM and a drill template for Tayda drilling.
The PCBs were fabbed with 2 daughter PCB boards for 3PDT true bypass (you only need one, so there is a spare).
I would like to ask £12 GBP for each of these, shipped worldwide. Drop me a line at info@gigaheartsfx.com if this sounds reasonable
here is a proper janky demo on a bass, side by side a real EHX big box BMS - I think they sound remarkably similar if not identical.
The filter is a tad lossy; there is a trim pot on board to balance the outputs when engaged vs disengaged.
I was waiting to hear NIB in that demo. That sounds great.
Sent from my iPhone using Tapatalk
PMs sent to interested parties.
This sounds and looks great! Very much up my alley. PM me if you still have any PCBs. I just got back from a trip to S. Korea so probably missed the boat as it were.
Still a couple unspoken for - I have PM you Bret.
Cheers
Very cool. Looks cool, sounds nasty! Email sent.
replied. 2 left
All boards ordered posted. 1 left.
Already got mine, thank you sir!
@LaceSensor, missing the value for R7 in the BOM and it's in the shadow of a cap in your gut shot so I can't reliability band count. Think there's orange brown and black there but not sure...
And man, you pulled out all the odd all resistor values. I think I used 4-5 values for the first time. 😂
There may be a few caps in the BOM that are non-existent. Had to use my fingers and toes to count them so I may be wrong. I'm about 5 caps and R7 away from being done.
Thanks again for sharing this!
R7 is 27k
As for the wierd values, its what the schematic called for I guess :)
Cheers
My bad for any errors. Ive updated the first page now.
As for missing caps let me know specifically what I have mis-labelled there. thanks
It does jump from C21 to C28 with nothing in between
C28 is added to C19 in parallel. The original part of that filter schematic is not on the original MS (hence the bypass toggle) and is indeed lifted ffrom Aleph Null via a datasheet for a PT2399 delay. Is a multiple feedback Low pass filter. The freuqency can be adjusted via C19 - if you want you can just put a 680pF or whatever your preference is up to about 1.5nF ish and forget C28. I found the 680pF can be a tad limited with bass, its grand with guitar. Hence you can mess around. The pads for C28 could also be used to switch in other caps ?
This was hopefully mostly captured in my build notes, towards the end of the BOM doc
"C19 and C29 are in parallel, and approximate a 680p cap. I found it useful try one cap depending on the tone you prefer. Lower (total) values of C19 and C29 will give "peakier" and harsher treble sounds. Higher values will darken the filter. Try anything from 220p up to 2n2 in total. You can simply put a 680pf cap in either position and call it a day 😊"
Awesome. Thank you!
Hello folks
all PCBs are now spoken for. Thankyou for those who supported that, helps me cover the costs of doing about 8 PCBs on this (!)
I wanted to let you know that I made a rev with a SMD footprint for the LM13700 - so I can confirm that SMD part will work (obviously, with the rev in your hands you would need an adaptor PCB, but it will be viable).
Cheers
I just need pots and wiring on my build. Caught Covid again a week ago and been tied up with home renos.
Looking forward to wrapping it up soon though.
Thanks again for putting this out there in the wild. I'll report in once done!
Cool. I am looking forward to seeing how everyone tackles this build.