MXR Flanger clone

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Spencerleehorton

Well-known member
Joined
May 12, 2012
Messages
4,031
Location
Felixstowe, Suffolk, UK
Hi All,

thought id document my guitar pedals journey, I am going to replace my Line 6 mod pedal for some analogue pedals as anything line 6 seems to destroy tone. ive already done the Dyna-Comp and this turned out nice.
I plan to make Phase 90 (script version) and Univibe along with the MXR Flanger.
I already have a few pcbs printed from years ago for the Univibe, so just need to populate and box up.
The Phase 90 is a nice simple little pcb so shouldnt take much time.
The MXR Flanger seems a little more complicated, using chips im not familiar with and i wanted to talk about the SAD1024 replacement which is the MN3007. I understand the footprint is different but wanted to check ive got my head around it correctly.
pin 1 the same, pin 2 CP1 connect to 8 and 10 of SAD1024?
pin 3 IN connect to 2 and 15 of SAD1024?
pin 4 Gate Voltage to pin 9 on SAD1024
pin 5 Drain Voltage to pin 7 on SAD1024
pin 6 CP2 connect to 3 and 14 on SAD1024
pin 7 OUT1 connect to 15 and 16 on SAD1024
pin 8 OUT2 connect to 11 abd 12 on SAD1024

I have a few 4013 chips.
i think i can use either 5532, TL072 or 4558 chips which i have loads of.
Transistors i think i can use 2n5088.

any other considerations i would welcome.

regards

Spence.
 
It's been a few decades since I used these but the SAD (reticon) and MN (matsushita) parts were opposite polarity MOS so the output source followers require loading with pull downs instead of pull up load resistors. 

I don't know if the mn3007 is the same length as SAD1024 (512 stages IIRC) which can make a difference for flanging (delay length).

IIRC the MN parts were higher capacitance and made dedicated clock drivers but I drove the shorter MN3001 with CD4013 FF (back in the '70s) I never used a MN3007 so don't know about it.

A flanger and a phasor are different but similar. A phasor uses phase shift to create combing, and a flanger uses time delay to create combing. Similar but different, flanging is more complex (more combs).

JR
 
skip the MXR and go for the AD/A.

fuzz?  velvet katana

chorus?

Boss CE 2

wah wah? buy an inductor and 10,000 cycle pot from Mike Fuller.

they got mucho forums on this stuff if you do not find any pedal geeks here,
 
Those two CCD's are not the same, very different generations. Try asking at dedicated guitar pedal cloning forums, there will probably be someone that tried it before.

Jakob E.
 
Spencerleehorton said:
Hi CJ,
I've checked the data sheets to both the sad1024 and the MN3007, could you do the same and let me know what you think please?

Regards

Spence.
Where do we send the consulting bill?  ;D

The SAD1024 is a dual 512 stage N channel (positive supply) MOS analog shift register.

The MN3007 is a single 1024 stage P channel (negative supply) MOS analog shift register.

The obvious difference they use two different polarity PS. The MN3007 is longer so for the same clock frequency range it will not get as short as the SAD 1024 (the HF end of the flanger sweep).

I used the MN3001 in my Popular Electronics delay line/flanger kit, back in the mid 70s. I used the SAD1024 in Loft Studio delay line flangers (and other Reticon parts in consumer delay products for Bozak). 

You could make a flanger with MN3007 but won't sound the same as SAD1024. Since the SAD1024 has long been obsolete modern guitar pedal designers don't have that option.

JR
 
Spencerleehorton said:
Ok good to know, I've found a few sad1024 for £20 so I think I'll order one and start etchin!
That sounds like a lot of money for a chip that has been obsolete for decades. Probably that valuable to people trying to keep old gear from back then working.

JR

PS: I wonder how hard it would be to mimic an old delay effect with a cheap micro...
 
I seem to remember 20 years ago or so technical papers written about modeling the distortion mechanisms inside charge coupled devices like analog shift registers, not simple and I'm not sure about the magic people are searching for therin..

I was using BBD technology for studio gear when the market was more than happy to move on to cleaner digital delay technology.

Enjoy...

JR 
 
JohnRoberts said:
That sounds like a lot of money for a chip that has been obsolete for decades. Probably that valuable to people trying to keep old gear from back then working.

JR

PS: I wonder how hard it would be to mimic an old delay effect with a cheap micro...

Actually thats quite cheap for a SAD1024, the market value is 4 times higher than that.
There's a lot of vintage pedals designs that depend on this chip so the demand is much higher than the present NOS supply.

If I was building the MXR Falnger I would use the SAD1024.

there's 2 nice forums for pedal building, you have most of the info there:

http://www.freestompboxes.org/

http://www.diystompboxes.com/smfforum/




 
Tricot chips are almost always counterfeit on eBay.  I wouldn't risk getting them from anyone except a very trusted source, and quite frankly using them for anything but a repair is a shame, plus there's nothing really special about them compared with the Panasonic bucket brigade chips in any case. The mn3007 is fairly safe but Smallbear issue safe bet.

You can save yourself a ton of work here -- Madbeanpedals sells a PCB for the MxR and it's a good one. Lectric Fx (scruffie and haberdasher from Madbeanpedals) sell an a/da PCB and a ton of people prefer it.
 
Ok, well this has put a spanner in the works now! The MN3207 seem to be the direct 8 pin replacement for the sad1024 right?
Also that cool audio v3207 is an 8 pin replacement.
As just regards the Mxr flanger, as this thread is what it's about, are these ideal replacements?
 
Spencerleehorton said:
Ok, well this has put a spanner in the works now! The MN3207 seem to be the direct 8 pin replacement for the sad1024 right?
um no not the same part but more similar (same polarity MOS). The SAD1024 is a dual 512 stage ASR, the MN3207 is a single 1024 stage so 2x the delay for same clock frequency as 1/2 sad1024
Also that cool audio v3207 is an 8 pin replacement.
As just regards the Mxr flanger, as this thread is what it's about, are these ideal replacements?

I just googled up a MXR schematic and they use the SAD1024 with the two internal 512 stages wired in series (output of first to input of second).  So indeed the MN3207 looks like a replacement for that specific application.

Back when I used the SAD1024 in a studio flanger I used the shorter single path (1/2 1024) for shorter delay and more extreme flanging effect. 

If your goal is to replicate the MXR flanger, the MN3207 looks like it would work.

The MXR micro flanger used the RETICON 512D (512 stages with clock driver built in). Which will give short delay like my studio flanger. I used the 512D in my second generation studio box.

If MXR sells a re-issue of the micro flanger I'd look inside one, but I'd use a micro processor these days, probably cheaper too...

JR
 
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