Maestro - MPF-1

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
Bernardduur
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Post by Bernardduur »

So, I got this schematic under my eyes from the original manual; shame is that I have no scanner or something like that. So I made a little electronic version of it

Enjoy it! It is possible some stuff is overlooked, so please comment!

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gar13
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Post by gar13 »

Has anyone ever tried to build one of these? I'd love to try but I've never done it without a layout before...

gar13
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Post by gar13 »

Well, doesn't seem anyone has given this a shot before, so I'd thought I'd take a stab at it. Please keep in mind this is my first time laying out a pcb. Any advice would be greatly appreciated. I haven't figured out how to label the input, +9v, etc. pads or render an image with the BOM below yet. Here's what I have so far:
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Maestro MPF-1.gif

gar13
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Post by gar13 »

Boxed myself in on that one, Here's the start of another try...
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MPF1 v2.gif

treehugger
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Post by treehugger »

Thanks for the original schematics! I've been looking for those.

gar13, did you ever finish that? And did you build it? If you did, please post some sound clips of it or tell me if it's good :)

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nelson
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Post by nelson »

Thought I would bump this as from a cursory glance at the schematic it just doesn't *look* right to me.

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Post by treehugger »

nelson wrote:Thought I would bump this as from a cursory glance at the schematic it just doesn't *look* right to me.
What is wrong with them? I can't really check them myself as I'm not an electronics guy, so I wouldn't wanna build it if the schematics are wrong. I would have no idea of how to fix it.

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Post by Dirk_Hendrik »

Explain please?
I guess Bernard got that schem through the same source I got it in it's original version and made a redraw. Although I haven't checked it in detail I can tell the original works excellent and the source is pleased with the result.
Sorry. Plain out of planes.

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treehugger
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Post by treehugger »

Dirk_Hendrik wrote:Explain please?
I guess Bernard got that schem through the same source I got it in it's original version and made a redraw. Although I haven't checked it in detail I can tell the original works excellent and the source is pleased with the result.
I know it's a lot of trouble, but could I get you to run it over and let me know if anything is off compared to the original? That would be fantastic.

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Post by nelson »

It was just the way I was looking at the switching - took a second for me to get my head around it. :scratch:

It looks like a cool circuit.

I might dissect it some more and see if I can get rid of the annoying rotary switch. For a start you can make the Q variable with a pot and remove half the switch.

I just need to work out how to make the two overdrive settings switchable and I can get rid of the 4011, 4016 and the other half of the rotary and make the overdrive foot switchable.

:hmmm:

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Post by treehugger »

nelson wrote:It was just the way I was looking at the switching - took a second for me to get my head around it. :scratch:

It looks like a cool circuit.

I might dissect it some more and see if I can get rid of the annoying rotary switch. For a start you can make the Q variable with a pot and remove half the switch.

I just need to work out how to make the two overdrive settings switchable and I can get rid of the 4011, 4016 and the other half of the rotary and make the overdrive foot switchable.

:hmmm:
Why would you get rid of the 4011 and 4016? And does that change the tonal characteristics? Is that you on diystompboxes with the same name btw? I'm the-bna on there :P

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Post by analogguru »

The circuit around the 4007 is identical to the schematic which can be found in this thread:
https://www.freestompboxes.org/viewtopic ... ator#p2238
... and puretube´s "new invention" from 2007:
https://img.photobucket.com/albums/v437/ ... ve2138.jpg
https://img.photobucket.com/albums/v437/ ... B02164.jpg
which can be found in this thread:
https://www.diystompboxes.com/smfforum/ ... ic=59383.0

I don´t know, if he already tried to apply this for his next patent.... :wink:

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Post by nelson »

treehugger wrote:
nelson wrote:It was just the way I was looking at the switching - took a second for me to get my head around it. :scratch:

It looks like a cool circuit.

I might dissect it some more and see if I can get rid of the annoying rotary switch. For a start you can make the Q variable with a pot and remove half the switch.

I just need to work out how to make the two overdrive settings switchable and I can get rid of the 4011, 4016 and the other half of the rotary and make the overdrive foot switchable.

:hmmm:
Why would you get rid of the 4011 and 4016? And does that change the tonal characteristics? Is that you on diystompboxes with the same name btw? I'm the-bna on there :P
Yeah, it's me on diystomp.


I would get rid of the 4011 and 4016 as well as the rotary switch to make the pedal more versatile as opposed to just selectable Q presets. You would be able to get the same tones, but also all the different tones the circuit is capable of. Essentially making it a fully adjustable Parametric EQ with a switchable overdrive. If I was going to build this for myself I would also want the frequency to be expression pedal controllable.


Removing them wouldn't effect the tone as the 4016 is a switch and the 4011 is used as switching logic. However, you wouldn't be able to switch between presets on the fly with your foot.

For that, rather than breaking my ankle twisting a rotary switch with my bunions I would probably use a footswitch, using a 4013 and replacing the rotary with more electronic switching. Screw it, why not add another throw and have the variable Q pot on that at the same time. While we are at it why not make the gain on the overdrive variable too.

Damn feature creeping :lol:

:)

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Post by treehugger »

nelson wrote:
treehugger wrote:
nelson wrote:It was just the way I was looking at the switching - took a second for me to get my head around it. :scratch:

It looks like a cool circuit.

I might dissect it some more and see if I can get rid of the annoying rotary switch. For a start you can make the Q variable with a pot and remove half the switch.

I just need to work out how to make the two overdrive settings switchable and I can get rid of the 4011, 4016 and the other half of the rotary and make the overdrive foot switchable.

:hmmm:
Why would you get rid of the 4011 and 4016? And does that change the tonal characteristics? Is that you on diystompboxes with the same name btw? I'm the-bna on there :P
Yeah, it's me on diystomp.


I would get rid of the 4011 and 4016 as well as the rotary switch to make the pedal more versatile as opposed to just selectable Q presets. You would be able to get the same tones, but also all the different tones the circuit is capable of. Essentially making it a fully adjustable Parametric EQ with a switchable overdrive. If I was going to build this for myself I would also want the frequency to be expression pedal controllable.


Removing them wouldn't effect the tone as the 4016 is a switch and the 4011 is used as switching logic. However, you wouldn't be able to switch between presets on the fly with your foot.

For that, rather than breaking my ankle twisting a rotary switch with my bunions I would probably use a footswitch, using a 4013 and replacing the rotary with more electronic switching. Screw it, why not add another throw and have the variable Q pot on that at the same time. While we are at it why not make the gain on the overdrive variable too.

Damn feature creeping :lol:

:)
How does the overdrive work in this cirquit? Is the medium and sharp overdrive presets the same eq cirquit, but with the OD in it too? It would be cool to have Broad, Medium, Sharp and Variable Q, and with the OD being a SPDT switch or something. Unfortunately I have no idea how to do it :P

The "foot-control"-part isn't something I value that much anyway. Have you seen the switching angle anyway? Looks really uncomfortable to do by foot.

eurekaiv
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Post by eurekaiv »

Anyone save the schem for this? The one in the original post is a dead link. I got an original unit and it is mightily cool outside of the ridiculously oversized enclosure so I'd love to build a clone in a more pedalboard friendly box. :)

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Post by treehugger »

search on the diystompboxes.com forums. I posted it on there.

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Post by devastator »

Hi

Anyone have tried to do a clone of this pedal ?

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Dirk_Hendrik
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Post by Dirk_Hendrik »

devastator wrote:Hi

Anyone have tried to do a clone of this pedal ?

Confess guilty :mrgreen:
Sorry. Plain out of planes.

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Post by eurekaiv »

Found... thanks!!!
treehugger wrote:search on the diystompboxes.com forums. I posted it on there.

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Post by devastator »

Dirk_Hendrik wrote:

Confess guilty :mrgreen:
Now, you have to say more ! :mrgreen:

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