Mutron Flanger dissection.

[digi2t]

I am thinking that this is either going to have to be built with a charge pump circuit OR it will need to be directly fed with REGULATED 15VDC-18VDC depending on the build.

Personally, I don`t mind running it with an 18v DC or AC power supply (wall wart), and regulating down. I know some folks are not really keen on the wall wart, but like G_L says, there`s no room for a step down transformer.

If it`s good enough for the Tau Pipe Phaser, it`ll be good here.

[armdnrdy]

Okay guys still working on the redraw and I have a question about the switching and indicator LEDs.

From the schematic I've identified S1 (A&B) as the effect in/out switch, and S2 (A&B) as the pedal in/out switch.

Watching Dino's video: the effect switch has to be on for the pedal function to work. The rate LED only works when the "pedal" switch (S2) is not engaged.

LEDs: CR17 = power indicator
        CR16 = rate indicator
        CR14 = effect engaged indicator
        CR15 = pedal engaged indicator

Can someone take a look at the schematics to verify this?

Now the question: I'm looking to make this true bypass. Delete S1A, C33, R36, and R37 at the output.
Looking at S1B: When the effect is engaged the LED is lighted. When the switch is in the "other" position it is sending +V through R40 to pin 2 (non inverting input) of Z5A of the LFO.

What exactly is that voltage doing to the LFO?  
If this needs to be configured in this fashion I can add a 3PDT switch on the input and output with the third pole of the switch switching +V between the indicator and the LFO.

[Govmnt_Lacky]

Looking at S1B: When the effect is engaged the LED is lighted. When the switch is in the "other" position it is sending +V through R40 to pin 2 (non inverting input) of Z5A of the LFO.

Wouldn't this be indicative of the switching between sweeping the filter with the Speed pot as opposed to using the Pedal?

[armdnrdy]

Looking at S1B: When the effect is engaged the LED is lighted. When the switch is in the "other" position it is sending +V through R40 to pin 2 (non inverting input) of Z5A of the LFO.

Wouldn't this be indicative of the switching between sweeping the filter with the Speed pot as opposed to using the Pedal?

If you look at the schematic the LFO is disengaged via S2A when the pedal function is engaged.
S1B (effect in/out) sends +V to the LFO when the effect is disengaged. In that position neither the auto sweep (LFO) or the pedal sweep will work.
So I'm wondering what the +V is doing to the LFO when the effect/pedal is disengaged.

[digi2t]

Watching Dino's video: the effect switch has to be on for the pedal function to work. The rate LED only works when the "pedal" switch (S2) is not engaged.

That is correct. «Effect» is the bypass, «Pedal» switches between LFO or pedal control. The Rate LED is only operational when the effect is on, and in LFO mode.

[wavley]

Watching Dino's video: the effect switch has to be on for the pedal function to work. The rate LED only works when the "pedal" switch (S2) is not engaged.

That is correct. «Effect» is the bypass, «Pedal» switches between LFO or pedal control. The Rate LED is only operational when the effect is on, and in LFO mode.

This is a little bit how the Morley Pro Flanger operates, except that the effect light with pulse with the lfo (there is no rate light)... no pulsing when in manual sweep mode though.  I wish that I could find a schematic so we could compare.  The difference with the Morley is that there are 2 SAD chips.

[armdnrdy]

Another thing,

Dino can you provide dimensions of the foot pedal shutter and any useful information about it's travel?

There's been conversation of fitting this in a Morley enclosure......I have an idea to fit it in a Dunlop style enclosure such as the type sold by Small Bear, Mammoth, etc.

Toe stomp switch = effect In/out
Side kick switch (like the type on the crybaby 535Q, or the Snarling Dog's mold spore) for pedal / LFO
Board mounted IN/OUT jacks
Side mounted control pots like the crybaby 535Q, or the Snarling Dog's mold spore.

There is a lot of unused space in a crybaby style enclosure.

[digi2t]

Dino can you provide dimensions of the foot pedal shutter and any useful information about it's travel?

I can, but it might not be available until tomorrow. I won`t be home till late tonight. Quite honestly, the shutter is not exactly a thing of precision. Mechanically, it goes from fully blocking, to fully allowing the light to pass. The trimmer adjusts the range. Wether it be a Morley, or a Crybaby shell, the shutter can be easily fabricated to accomodate the sweep available of that particular pedal. A bit like the trimming we had to do for the Talking Pedal.

If you can fit it into a Crybaby, that would be great as well, though personally I would appreciate a Morley layout more. I have a Mold Spore, and a 535, and I find the side buttons a PITA. Although, I wonder if we could cut out a corner at the top of a Crybaby, like the Korg Mr. Multi, and stick the other switch there? The Mold Spore has this arrangement as well for the ring mod feature.

[armdnrdy]

Although, I wonder if we could cut out a corner at the top of a Crybaby, like the Korg Mr. Multi, and stick the other switch there? The Mold Spore has this arrangement as well for the ring mod feature.

The Mold Spore button is in a bad place as well!
I was looking at a crybaby shell for another build and had the thought to add another foot switch in the heel position. I'll take a look again to see if it can be done.
That would be kind of cool!

I can do a layout for the Morley enclosure as well, just get me the dimensions.

[armdnrdy]

Redrawn and retrofitted for the MN3007 as promised.

Link to PDF

https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/Mutron%20Flanger%203007.pdf

[Ronan]

I can do a layout for the Morley enclosure as well, just get me the dimensions.

Larry, the link below is the outline and hole positions of the pcb I did for the EH Talking Pedal, printed to pdf from the actual pcb software. I added in the dimensions. The important bits are the dimensions between the four mounting holes and their relationship with the cutout for the shutter. It wouldn't hurt to take the cutout for the shutter another 1/8" further as I found some shutters resting or hitting up against the slot because it wasn't quite deep enough. The four mounting holes are centered across the top-to-bottom centreline of the housing. I can measure up the internal dimensions of a Morley housing if you want. The idea with the EH Talking Pedal pcb is you removed the existing pcb and fitted this one in place. The Morley housing has lots of room for top-mounted footswitches (one each side), pots and LED's. I would be very happy for you to do a Morley housing layout as I am pretty strapped for time, any questions please ask! I also appreciate that some prefer the slimmer crybaby housing, I have some dimensions for some wah shells I bought too.

https://dl.dropboxusercontent.com/u/61170900/Morley%20pedal%20pcb%20outline.pdf

https://dl.dropboxusercontent.com/u/61170900/EH%20TP%20pcb%20in%20housing.JPG

Very nice schematic drawing!

I might have it all wrong but shouldn't pin 5 of the MN3007 go to power ground vs signal ground in order to get the full 15V? (this is what I was trying to say in post 76)

Regarding power supplies, it might be possible to accommodate external wallwarts whether they be AC or DC; and also a standard 9V DC input running with a charge pump, but those voltages will also need regulating to limit them to the 16V max of the MN3007. If all those options are on the pcb, the builder could choose their power supply option.

[Govmnt_Lacky]

Just to throw a wrench at the monkey... 

Will the 4046/4011 combination provide the umph to drive the MN3007's clock correctly? Will the default clock path for the SAD chip work just as well for the 3007? 

[armdnrdy]

Just to throw a wrench at the monkey...  

Will the 4046/4011 combination provide the umph to drive the MN3007's clock correctly? Will the default clock path for the SAD chip work just as well for the 3007?  

I don't see why it wouldn't. I believe that Dino posted the SAD's min/max frequencies and the 3007 will be able to cover it without a hitch.

As far as the clock path.....I'll route the boards with the best design rules in mind. There shouldn't be a problem with clock noise......I believe that the ADA designers already worked through this......how often do you see a virtual signal ground path in an older stompbox?

I think they had issues and this was their solution!.......It's a good one though!~

[armdnrdy]

I might have it all wrong but shouldn't pin 5 of the MN3007 go to power ground vs signal ground in order to get the full 15V? (this is what I was trying to say in post 76)

Regarding power supplies, it might be possible to accommodate external wallwarts whether they be AC or DC; and also a standard 9V DC input running with a charge pump, but those voltages will also need regulating to limit them to the 16V max of the MN3007. If all those options are on the pcb, the builder could choose their power supply option.

Ian,

Good catch!
Yes...the 3007 needs power ground, not signal ground for it's supply! Drawings revised and posted.

I like the option of power supply options.   I'll work it in!

Also, Thanks for the above links. I'll have a look when I get home this evening.

[Govmnt_Lacky]

I don't see why it wouldn't. I believe that Dino posted the SAD's min/max frequencies and the 3007 will be able to cover it without a hitch.

I always thought that the reasoning for the flip-flops and the gated buffers was to match the MN3007's capacitance in order to drive the delay times below the threshold of the chip to match the functionality of the SAD.

I will try to dig up the thread which explains it better 

[armdnrdy]

I always thought that the reasoning for the flip-flops and the gated buffers was to match the MN3007's capacitance in order to drive the delay times below the threshold of the chip to match the functionality of the SAD.

I will try to dig up the thread which explains it better 

I believe that I've come across that thread before.....see if you can find it!

My impression of adding a 4049 buffer in the ADA Flanger build was to achieve a higher clock rate. I've read that the spec'd limitations of the MN series are derived by assuming that you are using the MN3101 clock. The MN series BBDs can be clocked higher.....the MN clock has the limitations.

I built a MXR M117 clone where Federico (Fender3D) implemented a 3007 in place of the SAD......it works great.
Remember that the SAD in the Mutron Flanger is connected in series producing 1024 stages.....so basically...we're replacing a 1024 BBD IC with another model that takes a slightly different pin/supply configuration.

I think that Mark Hammer and someone else? discussed this issue in this thread a couple of pages ago.

[Govmnt_Lacky]

I believe that I've come across that thread before.....see if you can find it!

Been searching but... nothing so far. 

I believe the question came about due to my not understanding why the MN3007 couldn't be dropped into the standard M117 circuit. The SAD is used in series in that pedal as well.

The only thing I remember is that it was explained that it had to do with the differences in the clock capacitance between the SAD1024 and the MN3007 

[armdnrdy]

I believe that I've come across that thread before.....see if you can find it!

Been searching but... nothing so far.  

I believe the question came about due to my not understanding why the MN3007 couldn't be dropped into the standard M117 circuit. The SAD is used in series in that pedal as well.

The only thing I remember is that it was explained that it had to do with the differences in the clock capacitance between the SAD1024 and the MN3007  

I'll do some research to see what I can find. I like when things work correctly the first time with no surprises!

As far as the MN3007 not being a "drop in" for the M-117.....When other members were working on a daughter board with a buffer, I was in communication with Federico about his retrofit. I asked him more than once, "are you sure this thing doesn't need a buffer?"........ "the other guys say it needs a buffer." He was very adamant that it didn't.

With my 3007 build I was able to achieve the factory set points for the BBD clocking and hear no audible issues whatsoever.

[Govmnt_Lacky]

With my 3007 build I was able to achieve the factory set points for the BBD clocking and hear no audible issues whatsoever.

So you are saying that you believe the MN3007 can be a direct drop in replacement for the SAD1024 chip when it is run with both halves in series? No buffering needed?

And no adjustments to clocking?

[Fender3D]

^^
Yes and ny
when you're dealing with BBDs you have just one very important detail: BBD stages.
You have Td=BBDstages/fclock/2
this is the yes part...

Then you must face the chip gain:
Typ SAD's 1.2
Typ MN3007 0
This means you should recover the loss. Remember this value depends on load resistor also (and clock freq too)...

Then there's the clock input capacitance.
Your clock must supply the current needed with the given capacitive load:
110pF (per 512 section) with SAD and 700pF with MN.

Capacitive load may increase if tracks from VCO to BBD are long and/or near GND track(s)

This "ny" part may be easily overcome with a proper layout and adding a clock buffer if you're going to go over 2~2.3MHz