Mutron Flanger dissection.

[digi2t]

You know guys, I'm havin' a brain wave here...

I wonder if with a piece of thru-pad perf, and some header pins, if I could make an adapter board. Sort of like what I did with the XP-ALL+ (27C256 / 27C1001 conversion). Stick an MN3007 on the board, with the accompanying parts, and plug it into the Mutron SAD socket. That would give us a pretty good indication of whether it would work, no?

[Fender3D]

I wonder if with a piece of thru-pad perf, and some header pins, if I could make an adapter board.

You can,
just use SAD pin 15 to MN pin 3 as input,
SAD's clock pins to MN's 2 and 6
on perf, place 2 resistors and a cap for Vgg
R out + transistor on MN's output pins to SAD's pins 5 and 6
power supply pins as needed...

Edit:
Just realized...
Sorry Dino I meant:
R out + transistor on MN's output pins, transistor's emitter to SAD's pins 5 and 6

[digi2t]

I wonder if with a piece of thru-pad perf, and some header pins, if I could make an adapter board.

You can,
just use SAD pin 15 to MN pin 3 as input,
SAD's clock pins to MN's 2 and 6
on perf, place 2 resistors and a cap for Vgg
R out + transistor on MN's output pins to SAD's pins 5 and 6
power supply pins as needed...

OK. MN3007 has been ordered. Probably take a couple of weeks to get here, unless someone wants to lend me one ( ) in the meantime. There's none available locally.

I don't mind yanking the SAD out of the Mutron for the test (he says, as a bead of sweat rolls down his temple  )

[Fender3D]

I don't mind yanking the SAD out of the Mutron for the test (he says, as a bead of sweat rolls down his temple  )

You can safely handle your SAD after you've wrapped it in aluminum foil, shorting its pins 

[armdnrdy]

To ease everyone's mind....I dug into the data sheets and took to the net. This is what I found.

The Ccp (clock input capacitance) that Federico is referring to is listed as (typical) 110pf for the SAD and (max) 700pf for the MN3007. So we still don't know what we're looking at as far as a comparison. Kind of apples and oranges!

I looked at the original ADA Flanger schematics for some insight. The first version used the SAD1024 and a 4007/4047 combo for the VCO/clock. The second version used the MN3010 (CCP max 350pf) and the same 4007/4047 combo.  

I have also studied the ADA flanger reissue. The first version used the MN3010, then switched to two MN3004's, the series ended with a modified (traces cut, VGG resistors reconfigured, and a 78LXX regulator added on the trace side) circuit board and two MN3204's........all with the same clock configuration.

Some time ago I studied the original ADA flanger drawings and I was unsure why the 4049 buffer was added to the SAD1024 moosapotamus version. The production ADA didn't incorporate the buffer and yet possesses a sound and sweep range that is revered!

I found this little snippet from our one and only Mark Hammer that explains why and when a clock buffer is needed:
Reply #7

http://www.diystompboxes.com/smfforum/index.php?topic=67967.0

Now for the good news!
I really didn't know what that pesky little CD4011 was doing between the 4047 and the BBD clock inputs. I do now!
In that configuration it is a (not) inverter........a buffer!!



So...I think we're good to go!  

[armdnrdy]

Here's another explanation of what the 4011 buffer is doing.

[digi2t]

Here's another explanation of what the 4011 buffer is doing.

A bit off topic here, but just a question;

Could the 4011 (or other 40** chip) be used as an op amp is used in a buffer? If so, would there be any advantage/disadvantage?

[Govmnt_Lacky]

@Dino

I see where you are going with this but, is this just for information or do you want to implement it here?

I ask because the NEW question would be whether or not it would be worth it to reinvent the wheel? It might save a little space but is that space crucial here?

[12Bass]

Don't have the links at the moment, but I recall that a number of experimenters tried circuits both with and without a 4049 buffer and noticed a definite improvement in sound quality with the added buffer.  The clock pin capacitance of the BBD rounds the (square) clock signal as frequency increases and this smears the sound at higher clock rates.  My buffered SAD1024A sounds surprisingly hi-fi at 1 MHz!

[jdub]

Probably take a couple of weeks to get here, unless someone wants to lend me one in the meantime.

Hey Dino, if you still need, I have some 3007s and would be willing to loan one for the cause...

[digi2t]

@Dino

I see where you are going with this but, is this just for information or do you want to implement it here?

I ask because the NEW question would be whether or not it would be worth it to reinvent the wheel? It might save a little space but is that space crucial here?

Just for my own enlightenment bro. Nothing more. Just doing my best to go to bed a bit less stoopid. 

Probably take a couple of weeks to get here, unless someone wants to lend me one in the meantime.

Hey Dino, if you still need, I have some 3007s and would be willing to loan one for the cause...

PM sent.

[armdnrdy]

A bit off topic here, but just a question;

Could the 4011 (or other 40** chip) be used as an op amp is used in a buffer? If so, would there be any advantage/disadvantage?

The answer is no.
This type of "buffer" carries digital logic, it doesn't pass audio.
The CMOS family includes many different types of gates. When a high or low logic signal is applied at the input, you get varied results at the output depending on the type of gate it is.
There are logic truth tables that are a "legend" of sorts to keep track of the whole thing!
There are tutorials on the net that can explain CMOS logic much better than I can!

The 4011 in the Mutron Flanger serves two purposes. It inputs the single signal from the 4046 and produces a two phase clock as well as serving as a buffer.
IC9 A & D are opposite phase from the 4046 output and IC9 B & C are in phase with the 4046 output.

[armdnrdy]

To keep everyone updated, Ian (ronan) sent some useful information including dimensions of his Talking pedal board which includes the PCB mounting layout for the Morley enclosure as well as the Morley enclosure dimensions.

You may notice that in the schematic, I made some changes in the power supply section. I added additional filtering (always helps) and positioned C50 correctly. (After reviewing images of the component and trace side I discovered that the factory drawing was incorrect. I also noticed that the compander is missing power pins and power designations. (easy enough)

With that being said....
I'm going to work on a component overlay by adding components from the component side images to a flipped image of the trace side in a cad program.
When I'm finished, I'll verify the schematic circuit to the components and the board routing.

[digi2t]

Larry, thanks a bunch for the explanation of the buffer. I had the "DUH!" moment as soon as you said "digital logic". I was thinking apples, when we're dealing with oranges here. Thanks for setting me straight.

New question; I'm working on my adapter board, and I was wondering if I could use the R21 resistor/R80 trimmer arrangement on the Mutron, instead of the 10K BBD OUTPUT trimmer that you drew on the modded schematic? That way I would only require a jumper on the adapter board, rather than having to jump to the original board. I see that your trimmer goes to signal ground, rather than power ground, but if it works for the original, wouldn't it work here as well? I could jumper over R21 (750R) in a pinch.

This is what I whipped up;

[armdnrdy]

Hey Dino,

The original trimmer should work fine. I wouldn't worry about jumping the 750R. (the 750Ω is such a low value it won't make or break anything)

And I see you caught my mistake...good eye! The BBD output trimmer should go to power ground. I noticed that mistake last night when I picked out the lack of compander power. I'll post an updated schematic when I'm finished with the component layout and schematic confirmation.

I have some pretty good pictures I pulled from the "other" site about a year ago, but if I come across anything I'm unsure of....
I'll come calling.

[digi2t]

No problem Larry. Me and the Mutron are on standby.

As for the power ground catch, it really wasn't me trying to be smart. I just figured that if power ground was good enough for the original, than why not here. Like they taught us in the Navy, if it works....

jdub has been kind enough to offer a 3007 for testing, I should be getting it this week. I'll be building the adapter board in the meantime.

[Gus]

I don't understand the cloning of this model

I would take the best of the different flangers and make one with all the cool controls.

This one has two things the foot control and the start stop otherwise how is it different than other flangers?

[Fender3D]

Larry, thanks a bunch for the explanation of the buffer. I had the "DUH!" moment as soon as you said "digital logic". I was thinking apples, when we're dealing with oranges here. Thanks for setting me straight.

New question; I'm working on my adapter board, and I was wondering if I could use the R21 resistor/R80 trimmer arrangement on the Mutron, instead of the 10K BBD OUTPUT trimmer that you drew on the modded schematic? That way I would only require a jumper on the adapter board, rather than having to jump to the original board. I see that your trimmer goes to signal ground, rather than power ground, but if it works for the original, wouldn't it work here as well? I could jumper over R21 (750R) in a pinch.

This is what I whipped up;

You may take out R2 and VR1, shorting MN's pins 7 and 8.
Since you have Q1, you can use the cell R21/R80

[armdnrdy]

Here are a few other BBD output configurations.

[Fender3D]

Here are a few other BBD output configurations.

Larry,

this is ok until everybody just looks at MN functioning.
For completness sake, if you must sub this schematic with a SAD1024, you should add the output transistor, or, at least a capacitor, since @ OUTPUT pad you have a positive DC voltage