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DIY Stompboxes => Building your own stompbox => Topic started by: domenico on February 21, 2011, 11:05:30 AM

Title: Mxr flanger commande series - schematic/pcb pictures request
Post by: domenico on February 21, 2011, 11:05:30 AM
Hi do you have any picture of pcb or schematic for the subject pedal? I need to repair my pedal with damaged pcb traces.

Please let me know
Domenico
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: Mark Hammer on February 21, 2011, 11:19:22 AM
If you are referring to the black plastic one that uses an SAD512D, and calls itself "stereo" for some unknown reason (because it isn't), I have one.  http://www.effectsdatabase.com/model/mxr/commande/stereoflanger

Decent flanger, though it's small package makes it dismayingly short of some useful features.  The circuit is perilously close to that of the Micro-Flanger.  Steve Giles sent me a schematic for that one.  I think I posted it some time back but it would have been on photobucket, and I can't access that from work.  I'll try and direct you to it or repost later this evening.
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: domenico on February 21, 2011, 11:32:57 AM
yes it's that one ! I hope you can send me the schematic ! thanks !
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: zombiwoof on February 21, 2011, 03:11:44 PM
Quote from: Mark Hammer on February 21, 2011, 11:19:22 AM
If you are referring to the black plastic one that uses an SAD512D, and calls itself "stereo" for some unknown reason (because it isn't), I have one.  http://www.effectsdatabase.com/model/mxr/commande/stereoflanger

Decent flanger, though it's small package makes it dismayingly short of some useful features.  The circuit is perilously close to that of the Micro-Flanger.  Steve Giles sent me a schematic for that one.  I think I posted it some time back but it would have been on photobucket, and I can't access that from work.  I'll try and direct you to it or repost later this evening.

Are you sure it isn't stereo?.  You have the schematic, so I guess you are sure, but I ask because some of the early DOD stereo pedals have a three-lug output jack, and you use an insert-type cable to get the stereo separation.  I have no knowledge of the MXR pedal, but just thought maybe they used a similar jack setup on it.

Al
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: Mark Hammer on February 21, 2011, 03:24:25 PM
Nope.  It's mono-a-mono.  The only thing "stereo" about it is that, internally, it has a wet and a dry path....as every flanger does.

Sometimes, I wish there was an international regulatory body you had to apply to, accompanied by submission of a schematic, in order to acquire the right to use the term "stereo".  It's used in a VERY inconsistent manner across the industry.  :icon_rolleyes:
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: Mark Hammer on February 21, 2011, 08:17:56 PM
Here's the schematic.  Again, thanks to Stephen Giles for furnishing it.  Looking at the schematic, the LFO seems near identical to the LFO in the Phase 90.  This suggests that varying R41 will modify the sweep width.  I suspect that varying it between, say 1M5 and 500k will yield useful variations in width.
(http://i414.photobucket.com/albums/pp228/Mark_Hammer/Micro20Flanger-1.jpg)
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: domenico on February 22, 2011, 05:03:09 AM
is it the same circuit of the commande series ?
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: Fender3D on February 22, 2011, 06:15:46 AM
I don't know too much about the commande series, but this is the same circuit as my block micro flanger
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: Mark Hammer on February 22, 2011, 09:30:41 AM
Quote from: domenico on February 22, 2011, 05:03:09 AM
is it the same circuit of the commande series ?
Look at your board and you'll find pretty much everything there that's on the Micro-Flanger.  The Commande series' use of soft-touch PCB-mount mini-switches and plastic boxes probably failed to find favour with customers.  As near as I can tell, the only substantive differences between the Commande and Micro-Flanger are packaging.  You'll find much bigger differences between the 2000 series and these other two.
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: Mark Hammer on February 23, 2011, 08:59:21 AM
I popped mine open last night for a quick look, and it would appear the Commande and Micr-Flanger are slightly different, though I can't yet figure out how.  ???

Certainly the LFO is identical, the clock circuit is identical, and the filter stages appear to be identical.  However, where the Micro-Flanger uses a total of 3 op-amps (TL062 and TL061), the Commande unit uses a pair of TL062s, and it would appear that both halves of each chip are on duty.  I can't quite figure out what that 4th op-amp section is being used for.  Perhaps it is involved in filtering, or maybe it is a buffer stage; I can't tell.
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: space_ryerson on February 25, 2011, 02:56:38 PM
Quote from: Mark Hammer on February 22, 2011, 09:30:41 AM
Quote from: domenico on February 22, 2011, 05:03:09 AM
is it the same circuit of the commande series ?
Look at your board and you'll find pretty much everything there that's on the Micro-Flanger.  The Commande series' use of soft-touch PCB-mount mini-switches and plastic boxes probably failed to find favour with customers.  As near as I can tell, the only substantive differences between the Commande and Micro-Flanger are packaging.  You'll find much bigger differences between the 2000 series and these other two.
Hi Mark, do you have a copy of the schematic for 2000 series Stereo Flanger? I have one of these, and like it very much. The problem I have with it is that it's bypass is pretty noisy, and cuts off some high end. I've been using a bypass box with it for the past decade or so, but I'm thinking of going with RG's relay bypass solution, and see if the buffers can be replaced/modified to be lower noise. I've been meaning to trace out the circuit, but for some reason I really loathe tracing out double-sided circuit boards.
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: Mark Hammer on February 25, 2011, 03:40:16 PM
Sorry.  No schematic.
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: space_ryerson on February 25, 2011, 10:57:48 PM
Thanks anyway. I'm going to have to bite the bullet and trace this thing out one of these days! :)
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: pinkjimiphoton on March 10, 2017, 01:49:31 PM
fwiw, and sorry to bump a zombie, but i just was given one of these commande series flangers, and the board # is 103, which is mentioned on the schematic mark posted and seems to pretty much match mine with subtle differences.

i think i'm gonna hack it and add a width pot as mark suggested, been looking at it, where would be the best place to hack in a "depth" control?
i was thinking a pot hacked in somewhere around the + input of ic 1b, but i'm REALLy new at messing with these kinda pedals, so suggestions gratefully appreciated.
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: Fender3D on March 10, 2017, 02:31:41 PM
Hi Jimi,

you can swap R30 for a resistor + pot, otherwise altering R39 you get a "delay" control.
If you wanna change wet/dry ratio you may use a pot instead of R21
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: Mark Hammer on March 10, 2017, 03:29:58 PM
Quote from: pinkjimiphoton on March 10, 2017, 01:49:31 PM
fwiw, and sorry to bump a zombie, but i just was given one of these commande series flangers, and the board # is 103, which is mentioned on the schematic mark posted and seems to pretty much match mine with subtle differences.

i think i'm gonna hack it and add a width pot as mark suggested, been looking at it, where would be the best place to hack in a "depth" control?
i was thinking a pot hacked in somewhere around the + input of ic 1b, but i'm REALLy new at messing with these kinda pedals, so suggestions gratefully appreciated.
As R22 gets larger the delay is mixed lower down (i.e., less "intense").  So a 200-250k variable resistance between R22 and C11 will let you dial in less intense flanging sounds.  If you want vibrato you can either make R10 larger in value or simply use a toggle to lift one end of R10.

When it comes to phasers and flangers, you can either take the feedback from the end of the delay/phase-shift path and feed it back to an earlier point in that path, OR you can take the signal from the output of the mixing stage and feed it back to the input of the mixing stage to yield a slightly different-sounding effect.  I should note that higher feedback settings shave off more bottom in this circuit, yielding a less metallic or over-resonant "boxey" sound.

This circuit takes the feedback from the output of IC1B, after wet and dry have been combined, and feeds it back to the input of IC1A, just ahead of where wet and dry paths part ways.  If you have access to another flanger that uses the within-wet feedback path, do a comparison to see which kind of sound you prefer.

Finally, adding another dozen or 22-33pf on top of C15 will put you in chorus territory.
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: pinkjimiphoton on March 10, 2017, 03:32:55 PM
Quote from: Fender3D on March 10, 2017, 02:31:41 PM
Hi Jimi,

you can swap R30 for a resistor + pot, otherwise altering R39 you get a "delay" control.
If you wanna change wet/dry ratio you may use a pot instead of R21

thanks federico!!
i will mess with it and see what's what...

so if i replace r21, the 47k to ground with a 50k pot i can control the wet signal? is that right?

there's a little difference it looks like between my board and this, but it sure seems pretty close.

i figure since it's not worth much it's a worthy candidate for a rehouse and some mods ;)

time to fire up the iron and crack a brew... again, thanks sir!!
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: pinkjimiphoton on March 10, 2017, 03:45:11 PM
Quote from: Mark Hammer on March 10, 2017, 03:29:58 PM
Quote from: pinkjimiphoton on March 10, 2017, 01:49:31 PM
fwiw, and sorry to bump a zombie, but i just was given one of these commande series flangers, and the board # is 103, which is mentioned on the schematic mark posted and seems to pretty much match mine with subtle differences.

i think i'm gonna hack it and add a width pot as mark suggested, been looking at it, where would be the best place to hack in a "depth" control?
i was thinking a pot hacked in somewhere around the + input of ic 1b, but i'm REALLy new at messing with these kinda pedals, so suggestions gratefully appreciated.
As R22 gets larger the delay is mixed lower down (i.e., less "intense").  So a 200-250k variable resistance between R22 and C11 will let you dial in less intense flanging sounds.  If you want vibrato you can either make R10 larger in value or simply use a toggle to lift one end of R10.

When it comes to phasers and flangers, you can either take the feedback from the end of the delay/phase-shift path and feed it back to an earlier point in that path, OR you can take the signal from the output of the mixing stage and feed it back to the input of the mixing stage to yield a slightly different-sounding effect.  I should note that higher feedback settings shave off more bottom in this circuit, yielding a less metallic or over-resonant "boxey" sound.

This circuit takes the feedback from the output of IC1B, after wet and dry have been combined, and feeds it back to the input of IC1A, just ahead of where wet and dry paths part ways.  If you have access to another flanger that uses the within-wet feedback path, do a comparison to see which kind of sound you prefer.

Finally, adding another dozen or 22-33pf on top of C15 will put you in chorus territory.

thanks for the suggestions mark, very much appreciated!! hopefully i will find some cool stuff to do to this poor thing ;)
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: pinkjimiphoton on March 10, 2017, 08:20:38 PM
ok, so far all i've done is hack r41 into a width control. while i'm playing with it right now i just have a 1 meg trimmer tacked in. gonna probably give it it's own pot. i'm thinking about a 330k resistor with a 1m pot should be nice. but i gotta play with it, it may be "too much".

this really does seem to be the same circuit, BUT it's all... like... backwards. it seems like the opposite of how it's depicted, ie they use the "second" half of the dual ic's as ic 1 and the first half as ic 1b. really peculiar.

it's dodgy for me to try and read resistor codes too well these days so i'm using the beeper on my meter to find where stuff connects and it's taking forever. but i'm determined to make this thing sound half way decent somehow ;)

i'll report back with my findings. next is finding the proper resistor to lift to get it to just vibe, which it seems like it will be really good at.

thinking maybe a pot instead of a switch to mix the dry/wet, cuz imho it could actually use the flanging being just a little more intense

thanks for the tips guys, mucho appreciated! ;)
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: Mark Hammer on March 10, 2017, 09:05:10 PM
I've got too many damn flangers, commercial and built/unbuilt, including a Commande in a plastic box and a Micro-Flanger in a 1590B type box.  Because I have so many, I don't mod any given one too much, because I can always install that mod on another.
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: Fender3D on March 10, 2017, 10:06:13 PM
Quote from: Mark Hammer on March 10, 2017, 03:29:58 PM
....
This circuit takes the feedback from the output of IC1B, after wet and dry have been combined...

yes, but if you look carefully to schematic, feedback path re-enters IC1a on its inverting input, then it inverts dry signal subtracting it at mixing point

Quote from: pinkjimiphoton on March 10, 2017, 03:32:55 PM
...
so if i replace r21, the 47k to ground with a 50k pot i can control the wet signal? is that right?
...

yessir!

Quote from: pinkjimiphoton on March 10, 2017, 08:20:38 PM
ok, so far all i've done is hack r41 into a width control...

R30 is a better candidate for a width control if you connect its wiper at R41 ;) when wiper is at V+ LFO is bypassed
Altering R41 may help though, of course.
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: Mark Hammer on March 11, 2017, 08:36:16 AM
Quote from: Fender3D on March 10, 2017, 10:06:13 PM
Quote from: Mark Hammer on March 10, 2017, 03:29:58 PM
....
This circuit takes the feedback from the output of IC1B, after wet and dry have been combined...

yes, but if you look carefully to schematic, feedback path re-enters IC1a on its inverting input, then it inverts dry signal subtracting it at mixing point
But since IC1B is inverting, doesn't feeding it to the inverting input of IC1A put things "right" again?   Otherwise the clean portion of the signal coming through R10 would cancel out if it was then redirected back to pin 3 of IC1A.

What IS likely eliminated as an option is negative and positive flanging; something that I gather requires the ability to invert the delay signal specifically, without having any impact on the dry signal.
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: pinkjimiphoton on March 12, 2017, 03:58:30 AM
ok, so i dicked around with it a little tonite...

lifting the r10 thing does result in a fREEKishly good vibrato.... BUT then you can't bypass it, as it kills the dry signal completely. the switching i think just kills the wet signal. seems a small part of the schem may be missing on the right side.. i'm assuming the straight lines connect? like, just off r26 to where it says "in" on the switching?

this thing is weird. some of it seems to be right like the schematic, and some seems like it's on acid listening to slayer with batboy in a cave somewhere.

the "delay" mod (r39) works somewhat... still playing with that and the width (r41) control.

so i guess if i want it to vibe, i gotta use a dpdt so in vibe position it lifts the resistor, and in bypass it will still pass signal. it sounds really good, i don't think it's worth true bypassing. the 250k pot that's unmarked is a balance control between wet and dry.

looks like the ONLY way to be able to make it vibe and bypass it will be to tb it looking at the schematic. lots of places to dry up the wet signal, but not the dry signal. weird pedal!!!

i will say this,, this thing has a delightful wobble to it!

any other ideas? they'd be welcomed gratefully ;)
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: pinkjimiphoton on March 14, 2017, 09:14:40 PM
ended up leaving the dry signal intact. i may hack a switch in there but it's probably not worth molesting it that bad.

i ended up in the end finding two key resistors to play with, as suggested...

r39, and r41

r39, i hacked out the stock 1m resistor and put a 680k resistor on the input and a 220k resistor on the wiper of a 1 meg linear pot wired as a variable resistor. this gives it more depth and width and makes it vibe-ier sorta.

r41 i did similar, but used 330k on the input of the pot, and 22k on the wiper of a 500k linear pot wired as a variable resistor.. seemed to give it the most range of delay. any higher than that would whistle on the tops of the sweep if the other pot was turned up too high.

this gave it a nice balance. when you turn the first pot (the 1 meg one) down, you get a really nice classic flange. as you turn it up, it starts to get chorusey then vibey

the 500k pot seems to give it more wiggle and wobble.

dunno what i did or how it works, but it sounds better than what it was when i got it.

thanks for the tips guys!! ;)

i'll try and get some video at some point

so i guess pot one will be labeled flange/chor/vibe

and pot two wobble
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: Fender3D on March 15, 2017, 06:12:46 AM
Quote from: pinkjimiphoton on March 14, 2017, 09:14:40 PM
so i guess pot one will be labeled flange/chor/vibe

"FLORBE"  :icon_mrgreen:
Title: Re: Mxr flanger commande series - schematic/pcb pictures request
Post by: pinkjimiphoton on March 15, 2017, 08:02:58 AM
hahah, i love it!!