Author Topic: Mxr flanger commande series - schematic/pcb pictures request  (Read 10009 times)

Fender3D

Re: Mxr flanger commande series - schematic/pcb pictures request
« Reply #20 on: March 10, 2017, 10:06:13 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

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

yessir!

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.
"NOT FLAMMABLE" is not a challenge

Mark Hammer

Re: Mxr flanger commande series - schematic/pcb pictures request
« Reply #21 on: March 11, 2017, 08:36:16 AM »
....
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.

pinkjimiphoton

Re: Mxr flanger commande series - schematic/pcb pictures request
« Reply #22 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 ;)
listen loud. blaze one first:
https://drive.google.com/open?id=0BzMJxNNgY3_yc0JNd0VqdmNIWEk

I stand for Truth, Justice, and the American Way. @#$% TRUMP! YOU ARE EITHER ANTI FASCIST, OR YOU ARE ONE. #BLM

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pinkjimiphoton

Re: Mxr flanger commande series - schematic/pcb pictures request
« Reply #23 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
listen loud. blaze one first:
https://drive.google.com/open?id=0BzMJxNNgY3_yc0JNd0VqdmNIWEk

I stand for Truth, Justice, and the American Way. @#$% TRUMP! YOU ARE EITHER ANTI FASCIST, OR YOU ARE ONE. #BLM

#FuzzyGoodness

Fender3D

Re: Mxr flanger commande series - schematic/pcb pictures request
« Reply #24 on: March 15, 2017, 06:12:46 AM »
so i guess pot one will be labeled flange/chor/vibe

"FLORBE"  :icon_mrgreen:
"NOT FLAMMABLE" is not a challenge

pinkjimiphoton

Re: Mxr flanger commande series - schematic/pcb pictures request
« Reply #25 on: March 15, 2017, 08:02:58 AM »
hahah, i love it!!
listen loud. blaze one first:
https://drive.google.com/open?id=0BzMJxNNgY3_yc0JNd0VqdmNIWEk

I stand for Truth, Justice, and the American Way. @#$% TRUMP! YOU ARE EITHER ANTI FASCIST, OR YOU ARE ONE. #BLM

#FuzzyGoodness