The secret M117 flanger

[lars]

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?

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.

[jwin615]

Looking at the Peavey DSC-4 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?

[Scruffie]

Did anyone consider the possibility that maybe it's just being used for something very dull, like switching? For that fancy new LED?

[museums]

Looking at the Peavey DSC-4 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.

[Scruffie]

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?

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.

[jessenator]

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.

I'll PM you. Let me know if you need different angles than what I captured.

[Scruffie]

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.

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.

[museums]

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.

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.

[Scruffie]

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?

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.

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.