Mutron Flanger Clone

[Govmnt_Lacky]

WOW!!!     

Blown away Larry. Thank you so very much for all of the hard work!

Cant wait to get this going. Gotta find some FR4 big enough now 

[digi2t]

Outstanding piece of work Larry. Truly humbling.

It was an absolute treat to work with you on this baby. A collaboration worthy of the Ludwig Award. 

[Mark Hammer]

Larry is an absolute wolverine when it comes to involved projects, ain't he?  Once he sinks his teeth into it, he doesn't let go until it's DONE! 

The ECG1641 is an MN3007 substitute, right, not a 3207 sub?  If I'm right, and despite the fact that I have too damn many flangers already, I may have to give this one a crack.  I am willing to sacrifice my Morley power wah for the cause. 

[armdnrdy]

Gotta find some FR4 big enough now 

I used MG Chemicals 512 (6" X 9" 1/16" FR4) for the prototype.

Mouser stocks it at a reasonable price.

I included it with my order of:   
Piher trimmers
1.5µf tant
10µf bipolar elects
330Ω 1/2 watt resistor

Except for the long pin pots, (Mammoth or Small Bear) You should be able to find everything else at Tayda.

[armdnrdy]

The ECG1641 is an MN3007 substitute, right, not a 3207 sub?

Correct

I may have to give this one a crack.  

Shouldn't you finish your Hyperflange build first?  

I have a bit of a build backlog going now but.....I've been working with the ADA STD-1 factory docs as well as some Tycobrahe Pedal Flanger material.
We'll see what comes of it.
  

[Mark Hammer]

The ECG1641 is an MN3007 substitute, right, not a 3207 sub?

Correct

I may have to give this one a crack.  

Shouldn't you finish your Hyperflange build first?  

I have a bit of a build backlog going now but.....I've been working with the ADA STD-1 factory docs as well as some Tycobrahe Pedal Flanger material.
We'll see what comes of it.
  
  :icon_rolleyes:It's precisely these sort of distractions that have impeded me from completing the Hyperflange for 20 years.

[armdnrdy]

For further information:

Mutron Flanger Dissection thread here: http://www.diystompboxes.com/smfforum/index.php?topic=103542.0

Pedal Voltage control circuit discussion here: http://www.diystompboxes.com/smfforum/index.php?topic=103879.0

Bias voltage connected to In/Out jacks here: http://www.diystompboxes.com/smfforum/index.php?topic=104370.0

[Mark Hammer]

Not to be picky, but the first op-amp stage in the build document shows a 390k feedback resistor and a .047uf feedback cap.  Should that be 47pf, rather than nf?

[armdnrdy]

Hey Mark,

Please be picky! If anything was missed, I would like to correct it.

The cap you are referring to is C3 right?
The factory schematic lists it as a .047µf....but that can't be completely trusted.

Dino verified all of the component values.....but he can't be completely trusted either!  

I also verified what I could see in images from the net and that Dino provided.
I used this info to make a component designation overlay as well as a component value overlay.
I used this to verify the schematic.

I couldn't make out most of the caps from the images, but with a little "electronics archeology" I can tell if the size looks in the ballpark for the value listed.

This is an image of C1 and C3, both listed as .047µf.



Now.....time for me to learn. Why do the 390K and .047µf values look suspect?

[Mark Hammer]

I'm assuming - perhaps naively - that the feedback components ought to conform to the usual formula of F = 1/(2pi x R x C).  With a 390k resistor, that would make the high-end rolloff begin around 8.6hz.   Juuuuuuuusssstttt a little low.  If C3 were 47pf, that would be 8.6khz, which isn't hi-fi, by any stretch, but reasonable bandwidth for a guitar.

Is there something that *I* don't understand about feedback caps in unity-gain non-inverting op-amps?

[armdnrdy]

I just looked through folders of schematics for flangers and delays.
I see what you mean...I couldn't find any similar examples.

I think that the answer is in here somewhere.
http://www.physics.unlv.edu/~bill/PHYS483/op_amp_filt.pdf

[Govmnt_Lacky]

@Larry,

Any chance you could post some good gut shots of your build? Just so that us interested folks   can get an idea of the form/fit/function of the build.

Thanks!!

EDIT: Larry.... looking at the PCB layout. It appears that RX8 is connected to 2 traces. If you look near the "P" in Pedal Flanger 3007, when the layout is printed to size, the PCB pad for RX8 in this area connects to TWO traces. Is this correct?

[armdnrdy]

EDIT: Larry.... looking at the PCB layout. It appears that RX8 is connected to 2 traces. If you look near the "P" in Pedal Flanger 3007, when the layout is printed to size, the PCB pad for RX8 in this area connects to TWO traces. Is this correct?

Uhh.....yeah it looks like RX8 connects to two traces because it does!!.......but it's not supposed to!
Good catch Greg!

Here is the revised main board file with that fixed.

https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/Pedal%20Flanger%20main%20board%20.pdf

[Govmnt_Lacky]

Thanks for the fix Larry! 

Any chance of some pic uploads/gut shots? It is always good to see how the working unit was assembled 

[GodSaveMetal]

Thanks to fix it!! great EAGLE look, thanks!!!!!!!!!!!!!!!!

[armdnrdy]

Here are some images. There really isn't much to see that isn't detailed in the build document.

When viewed from the bottom, with the bottom cover removed, the LED/LDR board is oriented component side up.
The main board is oriented trace side up.
The controls which are mounted to the main board component side are "upside down" and exit through the top of the enclosure.
The LEDs which are mounted on the trace side of the LED/LDR board are "upside down" and exit through the top of the enclosure.

[Govmnt_Lacky]

Thanks again Larry. Exactly what I was looking for and more! 

[armdnrdy]

One of these days I'll have to take this all apart, strip the powder coating off of the enclosure, paint it, and put the artwork decal on all proper like and stuff. 

There are just too many projects!

[digi2t]

One of these days I'll have to take this all apart, strip the powder coating off of the enclosure, paint it, and put the artwork decal on all proper like and stuff. 

There are just too many projects!

Nooooooo..... leave it as is, and blow some minds when you step on it. I can hear the head scratching now.

That's why I don't dress my pedals anymore. Just leave them in a cloud of "What the hell was THAT?!"

Better yet, label it "Morley Pedal Flanger", and really mess with their minds.

[armdnrdy]

To keep everything together all orderly....I reworked the original Build Document posted on reply 19 to include the revised main board PCB print. (small mistake corrected)
Flangerland is safe again from non working PCBs.