Recent posts

#31

General Questions / Re: ZenGlory not working

Last post by rpark71 - June 28, 2026, 12:18:24 PM

I'll reply to myself...I think AI led me down the wrong path, many wrong paths to be honest so not sure this layout would ever function as planned so reverted to original ZenDrive layout, and pedal now works and sounds great.

#32

General Questions / ZenGlory not working

Last post by rpark71 - June 23, 2026, 04:52:02 PM

Hi all,

So I've built a pedal, using a Zen Drive tagboard layout from madbean and wanted to modify slightly so it had a toggle switch to go from Zen Drive using the BAT41 diodes and cleaner clipping, a bit like Morning Glory, using red LED's - a 'ZenGlory'. So I used Gemini, then pedal course version of ChatGPT to verify the new v14 layout (attached, as is original layout from madbean). So built the pedal and power LED comes on, I get bypass sound when pedal on/off, but not effect sound. One of the red LED's is permanently lit, but goes out if with power to pedal, you touch sleeve to metal jacks or enclosure. ChatGPT (DIY Guitar pedal pro v1.3 via Wampler pedal course) has gone through various tests using multimeter and audio probe. The idea was to power this at 18v, which the IC can do, but in testing I've used 9v from isolated power. Here are measurements:

IC voltages: pin 1 4.7v; pin 2 4.7v; pin 3 4.5v; pin 4 0v; pin 5 4.6v; pin 6 4.7v; pin 7 4.7v; pin 8 9.4v

Q1 is S 3.6v; D & G 4.6v
Q2 is S 3.6v; D &G 4.7v

When using audio probe I got guitar signal (not effected) at input, at switch lugs and then it stopped at tag 7 on layout v14. I had got R2 and R7 resistors mixed up, but replaced C3, R2 and R7. I still have same problem. So thought I'd post here for any thoughts, as about to give in. I feel like it might be a ground issue somewhere...it always seems to be a ground issue with my builds!

Any help appreciated.

cheers, Rich

#33

Open Discussion / Re: The secret M117 flanger

Last post by Scruffie - June 15, 2026, 10:58:35 PM

And in case anybody was wondering what crazy combination of transistors I have in there, check out this mess:
Q2 - BC108D (Metal can)
Q3 - MSPS7009 (older yellow top)
Q4 - 2N3904 (older silver face)
Q5 - 2N4125 (tayda stock)

I put sockets in those positions and swapped around just about every transistor I had on hand until arriving at that bizarre combo. The 5087/5088 combo just didn't work. There was hardly any modulation whatsoever. It had me checking and double-checking all the resistors and caps I put in the LFO/Clock circuit to see if I made a mistake somewhere. In the end, simple transistor swaps brought it to life. I would highly recommend putting sockets in those positions and just trying out different transistors. It's amazing how drastic of a change it can make. IE, if I take that 2N4125 out of Q5 and swap in a 2N5087, the pedal goes completely anemic. Ditto for any of the other positions.

Try a 2N3906 instead of 2N5087, it's better suited.

#34

Open Discussion / Re: The secret M117 flanger

Last post by lars - June 15, 2026, 08:45:46 PM

And in case anybody was wondering what crazy combination of transistors I have in there, check out this mess:
Q2 - BC108D (Metal can)
Q3 - MSPS7009 (older yellow top)
Q4 - 2N3904 (older silver face)
Q5 - 2N4125 (tayda stock)

I put sockets in those positions and swapped around just about every transistor I had on hand until arriving at that bizarre combo. The 5087/5088 combo just didn't work. There was hardly any modulation whatsoever. It had me checking and double-checking all the resistors and caps I put in the LFO/Clock circuit to see if I made a mistake somewhere. In the end, simple transistor swaps brought it to life. I would highly recommend putting sockets in those positions and just trying out different transistors. It's amazing how drastic of a change it can make. IE, if I take that 2N4125 out of Q5 and swap in a 2N5087, the pedal goes completely anemic. Ditto for any of the other positions.

#35

Open Discussion / Re: The secret M117 flanger

Last post by Scruffie - June 14, 2026, 11:14:59 PM

Changing R22 and R25 to 6K2 is a great mod! I definitely could hear more of that top end wash, where the high frequencies are more present than before. This mod should just be the standard value for the Collosalus in those positions.
For the mixing resistors, I went a little more conservative with a 130K/75K combo. I didn't want to increase the volume too much, but I definitely wanted some more dry signal. I noticed my build was always a little too "seasick" sounding, so this combo of mixing resistors added in 5% more dry signal.
Now things are sounding great! Thanks for the suggestions.

Glad it worked out!

As the 117 filtering stands it rolls off a little at the top end frequencies before it slopes in to its cut off and that 6k2 mod is just flattening out the round off (so it's just flat up to about 10kHz and then ski slope down) as the MN3007 is already better in the noise department than the SAD1024 but conversely naturally cuts more high end, ends up balancing out.

#36

Open Discussion / Re: The secret M117 flanger

Last post by lars - June 12, 2026, 06:47:06 PM

Changing R22 and R25 to 6K2 is a great mod! I definitely could hear more of that top end wash, where the high frequencies are more present than before. This mod should just be the standard value for the Collosalus in those positions.
For the mixing resistors, I went a little more conservative with a 130K/75K combo. I didn't want to increase the volume too much, but I definitely wanted some more dry signal. I noticed my build was always a little too "seasick" sounding, so this combo of mixing resistors added in 5% more dry signal.
Now things are sounding great! Thanks for the suggestions.

#37

Open Discussion / Re: I got a review by Premier ...

Last post by culturejam - June 12, 2026, 05:18:52 AM

Well done!

#38

Open Discussion / Re: The secret M117 flanger

Last post by Scruffie - June 11, 2026, 09:47:08 PM

Also making the mixing resistors 100k/56k removes the volume drop in a true bypass set up.

Just to double check:  the mixing resistors are R7/R8 on the 2022 schematic? So I would make R7 100K and R8 56K, respectively? I don't really notice a volume drop, but I do tend to like flanger to come in just a hair louder than bypass, so this could really take it to that next level.

I don't see the 2022 schematic in the archive file, but the (connected to the inverting input of the output op-amp) 150k becomes 100k, the 82k becomes 56k.

#39

Open Discussion / Re: The secret M117 flanger

Last post by lars - June 11, 2026, 06:15:08 PM

Also making the mixing resistors 100k/56k removes the volume drop in a true bypass set up.

Just to double check:  the mixing resistors are R7/R8 on the 2022 schematic? So I would make R7 100K and R8 56K, respectively? I don't really notice a volume drop, but I do tend to like flanger to come in just a hair louder than bypass, so this could really take it to that next level.

#40

Build Reports / Re: Grawlix — A Green Ringer w...

Last post by jimilee - June 11, 2026, 05:34:16 PM

THAT's the tune you pick to demo it??? 

I don't know any blues licks...

What ever key you're in, slide up about 3 frets and bend a lot.


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