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The secret M117 flanger

Started by lars, December 18, 2025, 09:47:47 PM

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Scruffie

Quote from: lars on June 06, 2026, 09:59:24 PM
Quote from: scruffiePlus, if you're really missing said high content, you can make R22 & R25 6k2 on the madbean collosalus and it should more than compensate for the difference.
Thanks for the suggestion! I'll have to try that out on my Collosalus (2022 version) build. I'm still not quite happy with the performance with it. I've noticed that Q2-Q5 have a huge effect on the sound, so I've been swapping several different transistors types in those positions. Right now it sounds pretty good, and has the most eclectic combo of transistors in those positions.
Let us know how it works out!

Yeah, all the transistors are doing different jobs so you will get a better sweep width with transistors best suited, don't need to go crazy, just 2N3904/2N5088 should be fine.

Also making the mixing resistors 100k/56k removes the volume drop in a true bypass set up.
Works at Lectric-FX

lars

Quote from: scruffieAlso 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 like to use essential oils to relax.
Which ones?
Well, chloroform; quite effective, that.

Scruffie

Quote from: lars on June 11, 2026, 06:15:08 PM
Quote from: scruffieAlso 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.
Works at Lectric-FX

lars

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.
I like to use essential oils to relax.
Which ones?
Well, chloroform; quite effective, that.

Scruffie

Quote from: lars on June 12, 2026, 06:47:06 PMChanging 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.
Works at Lectric-FX

lars

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.
I like to use essential oils to relax.
Which ones?
Well, chloroform; quite effective, that.

Scruffie

Quote from: lars on June 15, 2026, 08:45:46 PMAnd 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.
Works at Lectric-FX