MXR - Micro Chorus [schematic]
Hi all,
I've been enjoying this forum for too long without contributing anything.
I hope you like it:
Pics were re-uploaded here
If you need more pics, just ask
I've been enjoying this forum for too long without contributing anything.
I hope you like it:
Pics were re-uploaded here
If you need more pics, just ask
Thanks BB, good pics, We can to know the caps values?,
- lolbou
- Old Solderhand
Thanks, nice and useful pics!
A double-sided PCB... Will need a second layer on the SVG file ....
Still the date interests me! And the wiring (color - device)...
Cheers!!
A double-sided PCB... Will need a second layer on the SVG file ....
Still the date interests me! And the wiring (color - device)...
Cheers!!
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.
- Uh, no, I'm a mocker.
- Fender3D
- Cap Cooler
I reversed engineered it:
or PDF http://www.wizardinside.it/foto/schemi/micro_c-sch.pdf
I assumed the values for RV1, R28, C1, C9, TR1 from MXR micro flanger's schematic values (I reversed engineered it as soon as I bought it some years ago... both are really similar )
I only hope bluesbreaker62 list the caps value too 'cause they're too much different from flanger (please do it )
or PDF http://www.wizardinside.it/foto/schemi/micro_c-sch.pdf
I assumed the values for RV1, R28, C1, C9, TR1 from MXR micro flanger's schematic values (I reversed engineered it as soon as I bought it some years ago... both are really similar )
I only hope bluesbreaker62 list the caps value too 'cause they're too much different from flanger (please do it )
- Dirk_Hendrik
- Old Solderhand
Information
- analogguru
- Old Solderhand
Information
No mistakes on Rev 1.00 deserves the missing capacitor values, here you go:
C1: 50n
C2: 1n
C3: 1n
C4: 200p
C5: 300p
C6: 30p
C7: 10n
C8: 1n
C9: 50n
C10: 1n
C11: 1n
C12: 0,33µ
C13: 200p
C14: 20p
C15: 10n
C16: 20p
C17: 10µ
C18: 10µ
C19: 0,33µ
C20: 0,33µ
Please DON´T save the schematic as .jpg.
USE INSTEAD black/white .GIF or .PNG !
The schematic drawing will stay sharper and the file will be smaller.
analogguru
C1: 50n
C2: 1n
C3: 1n
C4: 200p
C5: 300p
C6: 30p
C7: 10n
C8: 1n
C9: 50n
C10: 1n
C11: 1n
C12: 0,33µ
C13: 200p
C14: 20p
C15: 10n
C16: 20p
C17: 10µ
C18: 10µ
C19: 0,33µ
C20: 0,33µ
Please DON´T save the schematic as .jpg.
USE INSTEAD black/white .GIF or .PNG !
The schematic drawing will stay sharper and the file will be smaller.
analogguru
There´s a sucker born every minute - and too many of them end up in the bootweak pedal biz.
- Fender3D
- Cap Cooler
Thanks analogguru
Sorry for double post, but I really don't know how edit the previous
Updated schematic with the caps values.
Added PNG http://www.wizardinside.it/foto/schemi/micro_c-sch.png
and GIF http://www.wizardinside.it/foto/schemi/micro_c-sch.gif,
but...
IrfanView blurred them too when converting from PDF
Sorry for double post, but I really don't know how edit the previous
Updated schematic with the caps values.
Added PNG http://www.wizardinside.it/foto/schemi/micro_c-sch.png
and GIF http://www.wizardinside.it/foto/schemi/micro_c-sch.gif,
but...
IrfanView blurred them too when converting from PDF
- analogguru
- Old Solderhand
Information
I didn´t know that you work directly into .pdf.
Anyhow here is the .pdf converted to .gif - first with ghostscript to .bmp and then with XnView (Freeware) to .gif - to show you what I mean.
resolution .jpg: 1123 x 793 (~ 100 dpi)
file size .jpg: 143.092
resolution .gif: 3508 x 2479 (300 dpi)
file size .gif: 95.015
the rest you can see below.
analogguru
Anyhow here is the .pdf converted to .gif - first with ghostscript to .bmp and then with XnView (Freeware) to .gif - to show you what I mean.
resolution .jpg: 1123 x 793 (~ 100 dpi)
file size .jpg: 143.092
resolution .gif: 3508 x 2479 (300 dpi)
file size .gif: 95.015
the rest you can see below.
analogguru
There´s a sucker born every minute - and too many of them end up in the bootweak pedal biz.
- estragon
- Breadboard Brother
Take notice biasing is set in practice to VREF minus four (4) diode drops, as Q1 is an emitter follower whose output is one diode drop below its base. This arrangement varies with temperature. Wether it matched the variation required by the SAD512 or not, that's another story.Fender3D wrote:3 must be the perfect number
'cause the same 3 diodes were in micro flanger and in DOD effects too
they'll avoid the BBD bias setting
Q: Can i convert this chorus into a flanger(Mxr micro Flanger)? though chorus and a flanger has some similarities..
tnx
tnx
- mictester
- Old Solderhand
Information
They're just there for the 3-diode drop they provide.Dirk_Hendrik wrote:Thanks!
Those 3 diodes give a serious
"Why is it humming?" "Because it doesn't know the words!"
anyone?distortion_gfx1 wrote:Q: Can i convert this chorus into a flanger(Mxr micro Flanger)? though chorus and a flanger has some similarities..
tnx
- analogguru
- Old Solderhand
Information
Why do you want to convert it ?
If you don´t like it as it is, sell the BBD-chip and you can buy two cheap flangers.
analogguru
If you don´t like it as it is, sell the BBD-chip and you can buy two cheap flangers.
analogguru
There´s a sucker born every minute - and too many of them end up in the bootweak pedal biz.
- Dirk_Hendrik
- Old Solderhand
Information
Both questions get the same answer, Nope.mistral wrote:SAD512D Replace or equivalent?
where i can buy it?
SAD512D's are made of dried Pygmee foreskin leather which is even rarer than unobtanium.
- mictester
- Old Solderhand
Information
You might sometimes see them advertised at stupid prices on Ebay - DON'T bother buying them. You're very unlikely to get one that works, and any that you do get will be desoldered from broken equipment.mistral wrote:SAD512D Replace or equivalent?
where i can buy it?
Regards
I remember this as being a sweet little chorus (correct me if I'm wrong, please), and I was thinking of reworking one to use something obtainable like an MN 3007. The delay with the 3007 will be too long, so the clock frequency will have to be increased to get similar results to the original. This could help with the aliasing problems....
OK. Updated Micro Chorus on the way!
"Why is it humming?" "Because it doesn't know the words!"
- theehman
- Diode Debunker
Information
If you could come up with a way to replace the SAD512D in non-working pedals with an MN3007, you'd be revered as a veritable GOD!mictester wrote:You might sometimes see them advertised at stupid prices on Ebay - DON'T bother buying them. You're very unlikely to get one that works, and any that you do get will be desoldered from broken equipment.mistral wrote:SAD512D Replace or equivalent?
where i can buy it?
Regards
I remember this as being a sweet little chorus (correct me if I'm wrong, please), and I was thinking of reworking one to use something obtainable like an MN 3007. The delay with the 3007 will be too long, so the clock frequency will have to be increased to get similar results to the original. This could help with the aliasing problems....
OK. Updated Micro Chorus on the way!
Ron Neely II
Electro-Harmonix info: http://electroharmonix.vintageusaguitars.com
Home of RonSound effects: http://www.ronsound.com
fx schematics and repairs
Electro-Harmonix info: http://electroharmonix.vintageusaguitars.com
Home of RonSound effects: http://www.ronsound.com
fx schematics and repairs
- mictester
- Old Solderhand
Information
It won't be a pin-for-pin replacement, but there's no reason why you couldn't have a little "above" board with a 3007 and some biasing components. You'd also have to change the clock frequency because the 3007 is twice as long as the 512...theehman wrote:
If you could come up with a way to replace the SAD512D in non-working pedals with an MN3007, you'd be revered as a veritable GOD!
I'll do a rework of the Microchorus, and see where we get from there. I'll do a Vero layout as well.
"Why is it humming?" "Because it doesn't know the words!"
- mictester
- Old Solderhand
Information
Here we are:
A reworked MXR Micro Chorus using an MN3007 and a few component changes. I also added presets for the BBD bias and for the mix between straight and delayed signals, so you can maximise your chorus sound. It's breadboarded, and works well as shown. I'm going to play around with the values in the multivibrator to shorten the delay, and recalculate the values in the filters to get more top end through the delay path.
Veroboard and PCBs to follow soon.
Enjoy!
A reworked MXR Micro Chorus using an MN3007 and a few component changes. I also added presets for the BBD bias and for the mix between straight and delayed signals, so you can maximise your chorus sound. It's breadboarded, and works well as shown. I'm going to play around with the values in the multivibrator to shorten the delay, and recalculate the values in the filters to get more top end through the delay path.
Veroboard and PCBs to follow soon.
Enjoy!
"Why is it humming?" "Because it doesn't know the words!"