There are so many versions of the MXR M117, it's not surprising there is one version that has pretty much flown under the radar for the last couple decades. Yes, there are people who know the version I'm talking about, but for the most part, it's still kind of a sleeper. Clear back in 1996, MXR made it's first reissue of the M117. There doesn't seem to be much information about that first reissue on the Internet. It appears they may have only been made for about 2 years. The majority of online demos for the M117 are of the originals or the "newer" reissues. A gut shot is nearly impossible to find of the 1996 version.
The '96 version was US-made and used good-ol through-hole components and a very interesting choice for the BBD: not one, but two MN3004's! In the world of flangers, that makes it much more rare than the SAD1024-based M117's. I don't think there is another flanger in existence that uses two MN3004's. This version also has two independent clock circuits as well, so it's easily the most complex version of the M117 MXR has ever made. A schematic would be awesome to check out, but is impossible to find.
So how do you spot one of these "post-vintage, yet vintage" versions? The easiest way is if there is a picture of the bottom plate. MXR didn't provide any battery power option in '96, so no battery doors.
If there isn't a picture of the bottom though, you can spot them by the paint. The first reissues were always a matte rough-finish gray color with no metal flake. So if it has metal flake charcoal paint, it's not the one.
The other odd identifying mark is the LED. On the '96 versions, the LED is one of the strangest colors of red I've ever seen for an LED. It's like watermelon Kool-Aid red when it's off. You can easily see the color difference when compared with the 2004-present versions.
So here are the pics:
(https://i.postimg.cc/gjbcPJzP/117front.jpg)
(https://i.postimg.cc/7YVHpwpr/117back.jpg)
The insides of these rarely see the light of day...
(https://i.postimg.cc/P5jX7N6Y/117a.jpg)
Dual MN3004's are under them pots...
(https://i.postimg.cc/3NGhSH2r/mn3004s.jpg)
Why did I bother posting any of this? I've still seen this rare version listed as "2004-present", and it generally get's lumped in with the newer ones that just aren't quite the same. So keep an eye out! You can still pick these up for pretty cheap considering how nice they are and how rare the BBDs are. You will never regret getting a hold of one of these early reissues. Highly recommended.
Happy hunting!
Very cool, thank you.
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Wow, this is pretty cool. I've always thought the SAD versions were easily the best but over the years I have my doubts as it was completely new back then and I've probably heard 50 flangers since then and have probably built 10. Plus my old-ass ears aren't likely as prime as my 17yr old version was.
So what's the gist of this circuit? Two delays running in parallel hoping for differences in components (piggy backed)?
Quote from: gordo on December 18, 2025, 11:52:41 PMSo what's the gist of this circuit? Two delays running in parallel hoping for differences in components (piggy backed)?
Without a schematic it's difficult to know what configuration they're running. It's odd that newer versions of the M117 look like they use a single MN3204. For whatever reason, they've never gone the MN3007 route, despite the fact the originals were running serial configuration and MN3007s are readily available. I guess BBDs are more than just stages and clock speed. There's something else going on that affects the final output.
Very cool 8)
This topic has already become "famous". If you do searches for anything having to do with a 1996 MXR M117 flanger on Google, the AI machine has already lifted several key pieces of information directly from my post, in some cases word for word. It's happened! As individuals we now have the ability to control the information shared with the entire world on various subjects. Maybe in the near future AI will tell us that 2+2 = 5. If enough blogs were to convincingly promote it, then it will happen!
"When you control the mail, you control...information!"
~ Newman
Print is not dead. The internet dies with another bubble.
I scooped one because of this thread and it sounds great. I haven't compared to the earlier version but I was a little surprised to see the MXR doesn't use the multiplex configuration found in most other pedals that started with an SAD1024. Would be interesting to tap the output off the first MN3004 as an alternate sound.
Quote from: museums on January 07, 2026, 10:31:43 PMI scooped one because of this thread and it sounds great.
Glad you were able to find one! It really is a great-sounding "all around" modulation effect. I would say it leans more towards the chorus side of things. But, if we could find a schematic I could see this version being an incredible modification platform. With two BBD's in there, you could easily set up through-zero flanging by dedicating one to the dry signal line. By dropping down to 512 stages, it would still get some great chorus sounds, but be able to pull off some amazing flanged tones as well.
Quote from: jessenator on January 07, 2026, 02:52:46 PMPrint is not dead. The internet dies with another bubble.
The Internet actually died quite a while ago. It's nothing like a digital library anymore. Social Media runs the show.
Here is an update on the trimmer settings inside. One disappointing thing I found out about this version is that it couldn't do those great theremin-style sounds with the Regen knob maxed out. An awesome example of what I'm talking about is at the beginning of Van Halen's, Outta Love Again. In my opinion, if an M117 can't do those sounds, then the trimmers inside aren't set up correctly. By adjusting the 20K trimmer on the right a little bit more counter-clockwise, I was able to get those great oscillation sounds when the Regen knob is maxed. I also adjusted the clock speed to a faster setting to keep it from getting that awful deep/seasick rubber-band sound that so many flangers are set up to do.
Here's the pic of the trimmers:
(https://i.postimg.cc/Y2WLwkHk/117trim.jpg)
It definitely sounds even better after the adjustments. Now the chorus has more of that "Andy Summers" sparkle.
Yet more proof people don't realize these exist. Here's one on Reverb right now for $100! Listed as "2004-present". (I would buy it if I didn't already have one)
Grab it!
https://reverb.com/item/96097137-mxr-m117r-flanger-2004-present-black (https://reverb.com/item/96097137-mxr-m117r-flanger-2004-present-black)
Quote from: lars on April 23, 2026, 01:29:30 AMYet more proof people don't realize these exist. Here's one on Reverb right now for $100! Listed as "2004-present". (I would buy it if I didn't already have one)
Grab it!
https://reverb.com/item/96097137-mxr-m117r-flanger-2004-present-black (https://reverb.com/item/96097137-mxr-m117r-flanger-2004-present-black)
Well it's 199 now.
Sent from my iPhone using Tapatalk
Should be sold out now ;D I got it for $100 and shipping+tax
Quote from: jessenator on April 23, 2026, 03:39:17 AMShould be sold out now ;D I got it for $100 and shipping+tax
So glad it went to somebody on the forum! And it's a steal of a price. Congrats. It is a fantastic flanger. I wouldn't recommend using the rubber foot control pieces though. The pots are the Achilles's heal of these in that they have plastic shafts, and aren't easily sourced. Using a foot to turn them is a great way to snap them off.
Quote from: lars on April 24, 2026, 08:19:03 PMI wouldn't recommend using the rubber foot control pieces though. The pots are the Achilles's heal of these in that they have plastic shafts, and aren't easily sourced. Using a foot to turn them is a great way to snap them off.
I always wondered about those things... Never actually had an MXR with them still on there, so good to know!
Quote from: lars on April 24, 2026, 08:19:03 PMQuote from: jessenator on April 23, 2026, 03:39:17 AMShould be sold out now ;D I got it for $100 and shipping+tax
So glad it went to somebody on the forum! And it's a steal of a price. Congrats. It is a fantastic flanger. I wouldn't recommend using the rubber foot control pieces though. The pots are the Achilles's heal of these in that they have plastic shafts, and aren't easily sourced. Using a foot to turn them is a great way to snap them off.
Smallbear stocks a small 3/8" bushing pot if replacements are necessary.
Just got out in the mail today. Choooooooo this thing cooks!
Came off of the box a bit crusty, but cleans up. Gonna have to hit it with some CRC and get the right pot lube, because it's unpleasant to touch...
IMG_20260429_153359.jpg
IMG_20260429_153621.jpg
IMG_20260429_115516.jpg
I did take off the foot knob covers, but there is is!
I'm sure someone like scruffie would know, but I wonder if there's something going on in the rest of the chip contributing to the better SNR over the 3204, and other products in the line. It definitely sounds smoother than my buddy's BF.
The 3204 and 3004 appear to have a small difference in snr (75db vs 87db). Strange that for the same stage count the 3004 is a 14 pin with six not connected, mimicking the 3204's pin out (if you chopped those six off). More complex inner workings?
edit: no, different voltage reqs, for one thing. Nope. Sad.
12db isn't a small difference. 10db is considered a doubling in volume...
@xvive MN3004 when
The MN3004 is definitely an odd duck. I think it would be more likely that a company like Xvive would make a new SAD1024 before taking on a chip that wasn't really used in guitar effects. That's what makes this version of the M117 so interesting...remember it has two MN3004's in there! It's probably the only guitar effect to ever do that. And it ultimately does sound/feel different than just going with an MN3007, despite the fact it's the same number of stages.
Now if we could just get a schematic...
Quote from: lars on May 03, 2026, 02:52:16 AMNow if we could just get a schematic...
I'd have to work up to it myself, having never traced anything more than a FF :P I wonder how much it would cost for Robert over at PPCB to trace it... man works miracles. Or Brian. I'd gladly loan mine to either of them. Looks like only a 2-layer to my eyes. Weird grid-style ground plane, like VFE does.
I haven't poked around in mine but is the SAD1024 MXR parallel multiplex or both sections in series? I thought it was multiplex which would make sense here as well with two devices and short delay times. I also haven't checked the clock freq here.
MXR-117-underpot-3.jpg
Quote from: jessenator on May 07, 2026, 09:30:09 PMMXR-117-underpot-3.jpg
What the heck are those?
Sent from my iPhone using Tapatalk
Quote from: jimilee on May 08, 2026, 12:46:01 AMWhat the heck are those?
Motorola multiplexers as clock(s?)
two MN3004s, two multiplexers ...mod isn't in my wheelhouse (yet), but I'm sure one day non-scientists like myself will make sense of what's happening here (https://www.electrosmash.com/mn3007-bucket-brigade-devices).
There are only TL072s on the top, as far as I could see (U10 and U5 were both 072s. Surprised not to find and 022):
MXR-117-top-2-lo.jpg
Moto version of the CD4013. Can produce a two phase clock source, guessing one for each chip.
The demo Jessenator posted reminded me of the couple of dual clock chorus pedals I have. Sounded like a separate modulation underneath the main modulation to my ears.
Maybe they have one 4013/14013 running as divided by 2 from the first clock?
This gives another hair brained idea of what could be done to mimic the more lush sounding mod effects out there: parallel/series, multiplexed designs using more commonly available BBDs?
I mean, someone's thought of it, I'm sure. Nihili novi sub sule
Quote from: jwin615 on May 08, 2026, 12:17:42 PMSounded like a separate modulation underneath the main modulation to my ears.
Maybe they have one 4013/14013 running as divided by 2 from the first clock?
I have noticed this sound from my pedal as well. There is a subtle 2nd modulation effect taking place in the background. It would be amazing to be able to mod the clocks to really take advantage of the fact this is basically two flangers running simultaneously! Again, the unobtanium schematic for this version is the key.
Looking at the Peavey DSC-4 (//http://) dual clock chorus. It has 4 controls, 2x speed and 2x depth controls for each "clock". It really only has one clock, but 2x LFOs(072s) that look to be combined into a comparator(U3-B)and fed into the 3101. I would think this could confuse or glitch the 3101 but it makes for a very lush chorus.
Perhaps something similar is occuring in the MXR. Or it is somehow creating a decade of the LFO?
Did anyone consider the possibility that maybe it's just being used for something very dull, like switching? For that fancy new LED?
Quote from: jwin615 on May 28, 2026, 05:10:00 PMLooking at the Peavey DSC-4 (//http://) dual clock chorus. It has 4 controls, 2x speed and 2x depth controls for each "clock". It really only has one clock, but 2x LFOs(072s) that look to be combined into a comparator(U3-B)and fed into the 3101. I would think this could confuse or glitch the 3101 but it makes for a very lush chorus.
Perhaps something similar is occuring in the MXR. Or it is somehow creating a decade of the LFO?
There are a bunch of dual LFO choruses from that era and in practice the clock just sees a different pattern of rising and falling voltages over time than with a single LFO. The LFO with the higher depth control generally has more influence over the movement of the overall voltage. With both depth controls in the middle you can get interesting non-linear LFO movement.
IIRC the Peavey is a little different because it has two different LFO shapes.
Quote from: lars on May 16, 2026, 02:20:18 AMQuote from: jwin615 on May 08, 2026, 12:17:42 PMSounded like a separate modulation underneath the main modulation to my ears.
Maybe they have one 4013/14013 running as divided by 2 from the first clock?
I have noticed this sound from my pedal as well. There is a subtle 2nd modulation effect taking place in the background. It would be amazing to be able to mod the clocks to really take advantage of the fact this is basically two flangers running simultaneously! Again, the unobtanium schematic for this version is the key.
My guess is because of the MN3004's piss poor clock to gain ratio and the fact there's two almost certainly in series what you're both actually hearing is basically a tremolo along with the flanger.
If someone posts some decent gut shots it shouldn't be too hard to trace and confirm seeing as we already have the 117 schematic.
Quote from: Scruffie on June 02, 2026, 02:35:26 PMIf someone posts some decent gut shots it shouldn't be too hard to trace and confirm seeing as we already have the 117 schematic.
I'll PM you. Let me know if you need different angles than what I captured.
Quote from: jessenator on June 02, 2026, 09:33:10 PMQuote from: Scruffie on June 02, 2026, 02:35:26 PMIf someone posts some decent gut shots it shouldn't be too hard to trace and confirm seeing as we already have the 117 schematic.
I'll PM you. Let me know if you need different angles than what I captured.
Thanks, unfortunately to get a good look at the traces you'd need to unsolder the pots.
But, I thought of a much simpler solution... just test for continuity between pin 2 of both MN3004, if it beeps, they share the same clock.
If it doesn't beep, check pin 2 of one doesn't match to pin 12 of the other.
Still no beep? Then it's time to test the CD4013 for continuity.
Quote from: Scruffie on June 03, 2026, 12:21:13 AMQuote from: jessenator on June 02, 2026, 09:33:10 PMQuote from: Scruffie on June 02, 2026, 02:35:26 PMIf someone posts some decent gut shots it shouldn't be too hard to trace and confirm seeing as we already have the 117 schematic.
I'll PM you. Let me know if you need different angles than what I captured.
Thanks, unfortunately to get a good look at the traces you'd need to unsolder the pots.
But, I thought of a much simpler solution... just test for continuity between pin 2 of both MN3004, if it beeps, they share the same clock.
If it doesn't beep, check pin 2 of one doesn't match to pin 12 of the other.
Still no beep? Then it's time to test the CD4013 for continuity.
Probed around in mine. One half of the inner 4013 handles generating the two phase pulses for each MN3004. The outer 4013 is then the other half of the clock circuit although I believe based on photos earlier in the thread that there is a single oscillator feeding the two flipflops. BBDs are in parallel like the original design.
Thanks for that, so it's just using one half of each CD4013? What an odd design choice... Definitely not using the chip handling oscillator division in parallel? That might make a little more sense in lieu of a clock buffer, given the BBD's have equal clock capacitance to an MN3007.
The BBD's were in series in the original which it did look like was the direction it was heading in the gut shots Jessenator sent me, is parallel confirmed?
Are you able to measure the clock frequencies as well out of interest?
Quote from: museums on June 03, 2026, 04:09:48 PMQuote from: Scruffie on June 03, 2026, 12:21:13 AMQuote from: jessenator on June 02, 2026, 09:33:10 PMQuote from: Scruffie on June 02, 2026, 02:35:26 PMIf someone posts some decent gut shots it shouldn't be too hard to trace and confirm seeing as we already have the 117 schematic.
I'll PM you. Let me know if you need different angles than what I captured.
Thanks, unfortunately to get a good look at the traces you'd need to unsolder the pots.
But, I thought of a much simpler solution... just test for continuity between pin 2 of both MN3004, if it beeps, they share the same clock.
If it doesn't beep, check pin 2 of one doesn't match to pin 12 of the other.
Still no beep? Then it's time to test the CD4013 for continuity.
Probed around in mine. One half of the inner 4013 handles generating the two phase pulses for each MN3004. The outer 4013 is then the other half of the clock circuit although I believe based on photos earlier in the thread that there is a single oscillator feeding the two flipflops. BBDs are in parallel like the original design.
There are two 4013s in the pedal, each with two flip flops. One of the 4013s dedicates one flip flop to each of the MN3004s to make the biphase clock pulses so each MN3004 has its own driver. Im honestly not sure this is even necessary considering the clock freqs (13KHz to 500KHz), which are roughly halved compared to an SAD1024 unit or generally any Panasonic BBD equipped flanger pedal. The other 4013 is the oscillator. Of the 4 flip flops available, I believe 3 are used.
I was reading the old schem wrong about the BBDs being in parallel. The input pins of the two MN3004s are connected in my unit and the clock phases are matched which IIRC is the differential operation shown in the SAD1024 datasheet. Maybe the folks at MXR looked at the performance of the Panasonic BBDs and traded super short delay times for better performance with differential configuration? The sound of the pedal is spectacular. Better than an SAD1024 MXR IMO.
The only DIY project I have seen that offered these alternate BBD configurations is the BYOC flanger, but Im pretty sure they were running parallel multiplex and calling it differential.
Side note - The lag here is like an hour or two for posts to appear. Never experienced that on another simple machines forum.
Quote from: Scruffie on June 03, 2026, 09:37:05 PMThanks for that, so it's just using one half of each CD4013? What an odd design choice... Definitely not using the chip handling oscillator division in parallel? That might make a little more sense in lieu of a clock buffer, given the BBD's have equal clock capacitance to an MN3007.
The BBD's were in series in the original which it did look like was the direction it was heading in the gut shots Jessenator sent me, is parallel confirmed?
Are you able to measure the clock frequencies as well out of interest?
Quote from: museums on June 03, 2026, 04:09:48 PMQuote from: Scruffie on June 03, 2026, 12:21:13 AMQuote from: jessenator on June 02, 2026, 09:33:10 PMQuote from: Scruffie on June 02, 2026, 02:35:26 PMIf someone posts some decent gut shots it shouldn't be too hard to trace and confirm seeing as we already have the 117 schematic.
I'll PM you. Let me know if you need different angles than what I captured.
Thanks, unfortunately to get a good look at the traces you'd need to unsolder the pots.
But, I thought of a much simpler solution... just test for continuity between pin 2 of both MN3004, if it beeps, they share the same clock.
If it doesn't beep, check pin 2 of one doesn't match to pin 12 of the other.
Still no beep? Then it's time to test the CD4013 for continuity.
Probed around in mine. One half of the inner 4013 handles generating the two phase pulses for each MN3004. The outer 4013 is then the other half of the clock circuit although I believe based on photos earlier in the thread that there is a single oscillator feeding the two flipflops. BBDs are in parallel like the original design.
Quote from: museums on June 04, 2026, 03:13:33 PMThere are two 4013s in the pedal, each with two flip flops. One of the 4013s dedicates one flip flop to each of the MN3004s to make the biphase clock pulses so each MN3004 has its own driver. Im honestly not sure this is even necessary considering the clock freqs (13KHz to 500KHz), which are roughly halved compared to an SAD1024 unit or generally any Panasonic BBD equipped flanger pedal. The other 4013 is the oscillator. Of the 4 flip flops available, I believe 3 are used.
I was reading the old schem wrong about the BBDs being in parallel. The input pins of the two MN3004s are connected in my unit and the clock phases are matched which IIRC is the differential operation shown in the SAD1024 datasheet. Maybe the folks at MXR looked at the performance of the Panasonic BBDs and traded super short delay times for better performance with differential configuration? The sound of the pedal is spectacular. Better than an SAD1024 MXR IMO.
The only DIY project I have seen that offered these alternate BBD configurations is the BYOC flanger, but Im pretty sure they were running parallel multiplex and calling it differential.
Side note - The lag here is like an hour or two for posts to appear. Never experienced that on another simple machines forum.
Quote from: Scruffie on June 03, 2026, 09:37:05 PMThanks for that, so it's just using one half of each CD4013? What an odd design choice... Definitely not using the chip handling oscillator division in parallel? That might make a little more sense in lieu of a clock buffer, given the BBD's have equal clock capacitance to an MN3007.
The BBD's were in series in the original which it did look like was the direction it was heading in the gut shots Jessenator sent me, is parallel confirmed?
Are you able to measure the clock frequencies as well out of interest?
Quote from: museums on June 03, 2026, 04:09:48 PMQuote from: Scruffie on June 03, 2026, 12:21:13 AMQuote from: jessenator on June 02, 2026, 09:33:10 PMQuote from: Scruffie on June 02, 2026, 02:35:26 PMIf someone posts some decent gut shots it shouldn't be too hard to trace and confirm seeing as we already have the 117 schematic.
I'll PM you. Let me know if you need different angles than what I captured.
Thanks, unfortunately to get a good look at the traces you'd need to unsolder the pots.
But, I thought of a much simpler solution... just test for continuity between pin 2 of both MN3004, if it beeps, they share the same clock.
If it doesn't beep, check pin 2 of one doesn't match to pin 12 of the other.
Still no beep? Then it's time to test the CD4013 for continuity.
Probed around in mine. One half of the inner 4013 handles generating the two phase pulses for each MN3004. The outer 4013 is then the other half of the clock circuit although I believe based on photos earlier in the thread that there is a single oscillator feeding the two flipflops. BBDs are in parallel like the original design.
Ahhh, this is making much more sense, so they've parallel multiplexed (I assume unless there's an extra op-amp to achieve differential operation) and halved the clock to achieve the same delay times as the original probably, as you note regards SAD vs. Panasonic, to avoid the MN3004's heavy signal drop off at those higher clock frequencies and also so there's not a heavier high frequency roll off from running them in series.
No, parallel clocks was probably a little overkill but suppose it doesn't hurt, especially with the longer clock traces.
Also helps makes sense as to why the later version just uses a single MN3204 but with heavier noise reduction circuitry.
Think the mystery is solved, still, might be interesting to trace and see if there was any other alterations to the circuit... I do notice an extra diode in the astable section area.
Yeah, the forum does appear to be having some issues, there's a note on the homepage up at the top right.
Quote from: Scruffie on June 04, 2026, 06:07:37 PMYeah, the forum does appear to be having some issues, there's a note on the homepage up at the top right.
Yeah, it's been doing that a while now. Occasionally I get someone else's account on the main page...
Quote from: Scruffie on June 04, 2026, 06:07:37 PMThink the mystery is solved, still, might be interesting to trace and see if there was any other alterations to the circuit... I do notice an extra diode in the astable section area.
This is seriously cool. LMK if you need a donor. Not that there are any 3004s to build anew :P
Quote from: jessenator on June 04, 2026, 07:23:50 PMQuote from: Scruffie on June 04, 2026, 06:07:37 PMYeah, the forum does appear to be having some issues, there's a note on the homepage up at the top right.
Yeah, it's been doing that a while now. Occasionally I get someone else's account on the main page...
Quote from: Scruffie on June 04, 2026, 06:07:37 PMThink the mystery is solved, still, might be interesting to trace and see if there was any other alterations to the circuit... I do notice an extra diode in the astable section area.
This is seriously cool. LMK if you need a donor. Not that there are any 3004s to build anew :P
The thing is you wouldn't need MN3004s because this version is clocked low enough that you could use MN3007s and clock it at normal freqs and get the same results.
Yeah, I'd only really trace it just for completion, as you say, no MN3004 and I don't think there's anything majorly exciting hidden in there, just an interesting little piece of MXR history.
If you're up to de-soldering the pots I'll have a look over though when I get a chance, not impossible they've tweaked here and there.
The MN3004's have a minute amount of extra high frequency content over the MN3007 but then you're just trading benefit in one area for some negatives in another... at the time Panasonic had only stopped producing BBD's a few years earlier so the choice of chip may have just been what was practical to source.
Plus, 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.
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.
Quote from: lars on June 06, 2026, 09:59:24 PMQuote 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.
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.
Quote from: lars on June 11, 2026, 06:15:08 PMQuote 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.
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.
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.
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.
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.
Another one popped up for cheap on Reverb. At least the listing correctly identifies it as "1997", but it's still way below what these things are worth:
1997 MXR M117 (https://reverb.com/item/99025932-mxr-m117r-flanger-1997-works-perfectly?bk=eyJhbGciOiJIUzI1NiJ9.eyJqdGkiOiI0MjljMWYwZC1hMDNiLTRmYjYtYTEwMS1mZmJmNjc5NWFlY2MiLCJpYXQiOjE3ODMyNzI1MDksInVzZXJfaWQiOiIiLCJzZXNzaW9uX2lkIjoiOWUyNmI1MWMtNmYyMi00NDFiLTliY2UtZGNiNDVhZDE3ZTk5IiwiY29va2llX2lkIjoiYmMyZDcxMTQtZGE4Yi00MTVhLTgzZDMtMDVmODY0NTRmNDlkIiwicHJvZHVjdF9pZCI6Ijk5MDI1OTMyIiwic291cmNlIjoiTk9ORSJ9.0FQ099LxRANyAxfpY7Rxt8bza1gVPj5uO-rocC2ZAjA)
Fine. I'll joins the club. Thanks for the heads up lars
Quote from: jwin615 on July 05, 2026, 08:06:45 PMFine. I'll joins the club. Thanks for the heads up lars
(https://media1.tenor.com/m/c_nXRCemL6QAAAAC/fsjal369-woogee.gif)
If you're one of us...you'll take a bite.
Mine came with NatSemi CD4013. Same rev PCB as Jessenator's. 5x 072s. And 4 beer soaked pots.
Quote from: jwin615 on July 12, 2026, 02:01:44 AMMine came with NatSemi CD4013. Same rev PCB as Jessenator's. 5x 072s. And 4 beer soaked pots.
And your trimmers aren't de-gooped
Quote from: jwin615And 4 beer soaked pots.
LOL. That actually might have made them work better. Those plastic pots they used in these are the one minus to this pedal. Cheeeep.
Quote from: jwin615 on July 12, 2026, 02:01:44 AMMine came with NatSemi CD4013. Same rev PCB as Jessenator's. 5x 072s. And 4 beer soaked pots.
If you end up replacing the pots take a few photos of the board while they're out so we can take a look at the circuit ;)
Quote from: lars on July 12, 2026, 07:46:56 PMQuote from: jwin615And 4 beer soaked pots.
LOL. That actually might have made them work better. Those plastic pots they used in these are the one minus to this pedal. Cheeeep.
Yeah. I don't know why these were used so much in the 80w and 90s. I had a DOD performer chorus(SAD) shipped with one layer of bubble wrap in a box twice the necessary size recently. Stupid plastic pot sheered right off.
A touch of fader lube brought the Busch pots back around nicely.