A/DA Flanger retrofit with MN3007

[moosapotamus]

Here's a preliminary look at replacing the SAD1024 in the A/DA Flanger with a readily available MN3007...

http://moosapotamus.net/ADAflangerSCHmn3007.GIF

All the credit for this redesign effort goes to oldschoolanalog (Thanks, man!!!).

I've tried it out and it sounds really good to me. But it would be great if some of the more knowledgable folks here would give a look and chime in with thoughts, ideas, analyses, suggestions, etc...

Thanks again, OSA!

~ Charlie

[magikker]

Great news.

Does this mean you are ramping up for a new board or will I be able to finish my ad/a on one of the made for SAD1024 revisions.

[Auke Haarsma]

Very good news! I've been waiting for this.

Curious as I am, are there soundclips available? Is there a PCB?

[StephenGiles]

Now look here - do you mean to tell me that I've got to make one of these too??

A great job done there, I remember that the parts used in Mike Irwin's 1024 version around the BBD were chosen for good reason, has this been invoked around the 3007 or is it the standard circuitry?

[oldschoolanalog]

Well, well. I wake up this morning to see this. Seems Charlie was really on top of this one. Nice work, Moose!

Does this mean you are ramping up for a new board... 

That's what this R&D is all about.

...or will I be able to finish my ad/a on one of the made for SAD1024 revisions.

If you have an "old" board; and can't find an SAD1024; the retrofit circuit is relatively easy to build and set up.

Very good news! I've been waiting for this.

Are you going to be adding this to your multi f/x extravaganza?

Curious as I am, are there soundclips available? Is there a PCB?

It sounds just like the other 3 A/DA's  I compared it to. There are plenty of soundclips of the A/DA out there. PCB soon come.

Now look here - do you mean to tell me that I've got to make one of these too??

Of course Sir!  You know one can never have enough of these... 

I remember that the parts used in Mike Irwin's 1024 version around the BBD were chosen for good reason, has this been invoked around the 3007 or is it the standard circuitry?

Except for the 100k trimpot at the 3007 output (more on this later), it is the standard circuitry as far as the A/DA revs. 3 & 4 go. The MN based versions. After looking over the 3010 & 3007 datasheets I realized they had very similar, and in most cases, identical characteristics. I figured the 3007 should be as close to a "drop in" replacement as there was going to get. Except for the need to double the clock frequency, of course. The input, Vdd, Vgg, Gnd, and clock setups were taken directly from the A/DA rev3/4 schematics. So much for originality . But hey, at least I'm honest.
The output trimpot was decided upon after some trial and error. When all was said and done this seemed to be the easiest and most intuitive method for me (it also sounded the best).  EE guys so eloquently refer to this as an "Easter egg hunt". For me, it's "R&D" !

But it would be great if some of the more knowledgable folks here would give a look and chime in with thoughts, ideas, analyses, suggestions, etc...

Big time +1.
C'mon; I know you're out there with rage in your eyes and your megaphones!
BTW; for accuracy's sake; When I tested this in my unit; the R that's marked 150R was really 250R. Also, I would change that 10u cap for 22-33u.
That's it for now. More later.
All the Best,
Dave

[Auke Haarsma]

Very good news! I've been waiting for this.

Are you going to be adding this to your multi f/x extravaganza?

Curious as I am, are there soundclips available? Is there a PCB?

It sounds just like the other 3 A/DA's  I compared it to. There are plenty of soundclips of the A/DA out there. PCB soon come.

Awesome! Yeah, if it wasn't for the hard to get SAD1024 it would already be on the multi-fx crazyness . Now I will reserve space for this one!
If I understand correctly the pcb will be about the same size as the SAD1024 version?

[oldschoolanalog]

Awesome! Yeah, if it wasn't for the hard to get SAD1024 it would already be on the multi-fx crazyness . Now I will reserve space for this one!

You are really starting to scare me now 

If I understand correctly the pcb will be about the same size as the SAD1024 version?

Yes, it should be.
Dave

[moosapotamus]

BTW; for accuracy's sake; When I tested this in my unit; the R that's marked 150R was really 250R. Also, I would change that 10u cap for 22-33u.

I've updated the schematic with those values. Thanks Dave!

Just to confirm... Yes, the idea here is to produce an updated PCB, redesigned to use the MN3007 instead of the SAD1024. I'm guessing there will be enough folks interested to make it worthwhile to get a batch of these professionally fabricated for us.

And for folks who might already have one of the SAD1024 boards, retrofitting them with a small daughterboard to hold the MN3007 and associated components should be pretty easy to do. I know Dave already posted some pictures of his, but here's a peek at what the retrofit looks like in my build...



Without the SAD1024 and all the associated components, there should be plenty of room to snug that little daughterboard down in there.

~ Charlie

[theehman]

Is there any chance that this daughterboard could be adapted to allow the installation of the MN3007 into other SAD1024-based effects?

[oldschoolanalog]

Is there any chance that this daughterboard could be adapted to allow the installation of the MN3007 into other SAD1024-based effects?

While this was not designed as a "one size fits all" retrofit; I'm confident some adaptation could be made to allow the MN3007 to replace the SAD1024 in other circuits. Anything specific? (EM/DEM? )

Dave

[theehman]

Probably the best one would be the EH Memory Man.  Some of those use 2 or 3 SAD1024s an could get expensive if disaster strikes.

[bluesdevil]

Is there any chance that this daughterboard could be adapted to allow the installation of the MN3007 into other SAD1024-based effects?

While this was not designed as a "one size fits all" retrofit; I'm confident some adaptation could be made to allow the MN3007 to replace the SAD1024 in other circuits. Anything specific? (EM/DEM? )

Dave

This would be cool to work something up for:
http://gaussmarkov.net/wordpress/circuits/9v-electric-mistress/
I'm sure a lot of folks would appreciate it, including me!!

[RedHouse]

Is there any chance that this daughterboard could be adapted to allow the installation of the MN3007 into other SAD1024-based effects?

While this was not designed as a "one size fits all" retrofit; I'm confident some adaptation could be made to allow the MN3007 to replace the SAD1024 in other circuits. Anything specific? (EM/DEM? )

Dave

Couldn't a shoe-in be designed though? this is an opportunity to make a really great building-block upgrade/retrofit which would solve many problems.

Like when we had to retro-upgrade all those Craig Anderton projects back in the 80's. Would have been much more elegant if we could have used a daughterboard solution.

[theehman]

Is there any chance that this daughterboard could be adapted to allow the installation of the MN3007 into other SAD1024-based effects?

While this was not designed as a "one size fits all" retrofit; I'm confident some adaptation could be made to allow the MN3007 to replace the SAD1024 in other circuits. Anything specific? (EM/DEM? )

Dave

Couldn't a shoe-in be designed though? this is an opportunity to make a really great building-block upgrade/retrofit which would solve many problems.

Like when we had retro-upgrade all those Craig Anderton projects back in the 80's. Would have been much more elegant if we could have used a daughterboard solution.

My thoughts exactly.  If a 1024 upgrade/replacement can be made then it should only be a short step to a SAD4096 replacement.  There's an awful lot of vintage units that used SAD chips that could benefit from this.  Another great one would be the SAD512 to MN3307 conversion, especially for the MXR Micro series.

[Mark Hammer]

I should probably do the datasheet work myself, but I'm too lazy.  So, a key question, is the biasing of the MN3007 the same as for the SAD1024?  The retrofit is an excellent idea, but I'm just mentioning it in case there is actually more work involved than simply plugging in a retrofit.

[oldschoolanalog]

Before we digress too much from the original topic; does anybody have any comments/suggestions/opinions/questions about this as it pertains to the immediate task at hand (the A/DA retrofit). Something like this:

I remember that the parts used in Mike Irwin's 1024 version around the BBD were chosen for good reason, has this been invoked around the 3007 or is it the standard circuitry?

http://moosapotamus.net/ADAflangerSCHmn3007.GIF
335 views. One question. Hmm... Anybody?
Dave
PS: I have lots of thoughts about retrofitting other units. I just want to get this A/DA thing completed first.
Thanks!

[Mark Hammer]

In discussion with Mike, and seeing a first-hand demonstration of the circuit sitting right in front of me, Mike told me that the buffering is key, and the buffering is in place via the paralleled 4049 sections.  Without buffering, the MN3007 craps out around a few hundred khz, as the datasheet proposes.  WITH proper buffering of the clock lines, he has run it well out to 2mhz.  The limit is not set by the MN3007 itself, but by the manner in which the input capacitance of the clock pins interact with the click lines feeding them. Buffer, as shown in Charlie's diagram, and you should be good to go.

[oldschoolanalog]

Thanks Mark. The buffering is part of the circuit shown as tested w/the 3007. I clocked it to ~1.3MHz; Charlie clocked it a bit higher (~1.4MHz IIRC). We both got positive good sounding results. It's just nice to here the words "should be good to go" from somebody with your BBD knowledge.
All the Best,
Dave

[snap]

why not buffer with three inverters in parallel on each phase?
(immediately after the 4047?)

[Mark Hammer]

Thanks Mark. The buffering is part of the circuit shown as tested w/the 3007. I clocked it to ~1.3MHz; Charlie clocked it a bit higher (~1.4MHz IIRC). We both got positive good sounding results. It's just nice to here the words "should be good to go" from somebody with your BBD knowledge.

I owe what I know to Mike.