9V Electric Mistress retrofit with MN3007

[Toney]

Hey oldschoolanalog...

Looking great.
I just found this thread and I am more than interested.
I have had a drilled 9v EM board packed away for years - no SAD1024
So, yeah really appreciate what you have done here. 

[intripped]

I'm interested too!!!!
this is my first post here on diystompboxes so I would like to thank everybody for the immense help you gave and are giving me on building my effects - a further strong passion beyond music: seems to be a fever...

back on topic: not going to build it right now, there are too many projects going on, but for sure i'll try and build it!!
...still debugging my ADA flanger clone... with poor results

you're not wasting your time!
thanks again

[cathexis]

If anybody is interested in the changes done to make this work let me know.
If not, I won't waste my time posting info that is of no interest.

I'm interested, the EM drove me to the brink of murderous rage half a year ago. I had to hide my non-working boards, but I'm ready to take them out again.

[shadowmaster]

No one gets enough from building guitar effects in this forum. 

[oldschoolanalog]

Glad there's some interest.
All the info on the way this afternoon

PS: Be careful what you wish for. Tha guy behind the masonry (see sig) just wanted some Sherry...

[oldschoolanalog]

OK, here goes. First the necessary disclaimer. The work & results presented here are what worked well for me, and sounded good to me. If there is a better way to do any of this please say something. I don't want a repeat of the A/DA/3007 "issues". I  am by no means an expert when it comes to this. I am learning as I go. There are folks much more qualified to do this work (you know who you are ). All I have going for me is a willingness to learn and to try to take on projects that are discussed but not tried out. 
I read/research/study/compare/test & test & test some more. Such is my method.
Diatribe over.
Thanks...
See post below.

[oldschoolanalog]

Reference material:
9V EM PCB, schematic & layout: http://www.aronnelson.com/DIYFiles/up/9V_Mistress_project_file_v11_update.pdf
3007 retrofit board thread: http://www.diystompboxes.com/smfforum/index.php?topic=78270.0
Good reading:
http://www.diystompboxes.com/smfforum/index.php?topic=63044.0
http://www.diystompboxes.com/smfforum/index.php?topic=34607.0
First, parts not used/installed:R23,R19,R11,R12,,D1,D2,C5,C9. Changes: new value & explanation in (parenthesis): R5(jumper), R17(47K, improved bias range), C19(10pf, This was done to raise the max clock f), R38(15K, As you raise the max clock f, the low f goes up w/it. This restored the low clock f), C14(Added 3n3 in parallel w/the existing 2n2 [5n5 total], the regen was way too "thin sounding". This "fattened" things up a bit), The clock trim pot was wired as in the DELUXE EM schem. This gave a wider clock range. I put 47R in series w/R29, at their junction a 22uF cap was connected to GND. Also, 100n PS bypass caps were installed at every IC (3007 board also). These 2 things are there to provide a measure of "insurance", so to speak. Also, I was running short on certain parts, so for the retrofit board I used 22uF caps for C1,2,4 and I used 47R for both R1&5. Hookup of the retrofit board is fairly obvious. See photos, a few posts back (If you want more details, just ask! ) Just remember to DOUBLE THE CLOCK f's WHEN SETTING THIS UP. Double the BBD stages; double the clock f. Please feel free to ask Q's. Also, as I mentioned earlier, if anybody sees a way that this can be improved upon or done better; or; if anything is obviously incorrect, please say something. I feel this works and sounds as good, if not better than the EM's I have heard/owned in the past. Now who will be the first to try this?
Have Fun!
Dave

[quarara]

I  am by no means an expert when it comes to this.

this statement is clearly at odds with the huge amount of data you posted.
great job!

[jorge r]

oldschoolanalog

Sorry about my small knowledge, but what do you mean with " DOUBLE THE CLOCK f's WHEN SETTING THIS UP. Double the BBD stages; double the clock f " ? I wired the 3007 board like yuor pictures but no efect appears, just clean sound. I left the zenner.
Thanks to all who worked in this project.

     Jorge

[oldschoolanalog]

Hi Jorge,
First read the factory setup instructions posted here:
http://www.diystompboxes.com/smfforum/index.php?topic=67766.0
They are all a bit different, however where the factory notes spec a clock f of 20kHz or 35kHz (at pins 1 & 5 of the 4013). This is the setup f's for a 512 stage BBD. The 3007 is a 1024 stage BBD. To maintain the same delay one needs to double the clock f. Somewhere between 40kHz - 70kHz at pins 1 & 5 of the 4013. Experiment to see what sounds best to you.
If you have only clean sound, check the bias trim first. Let me know what happens.
I'll post more detailed hookup instructions later. Can you post a pic? That might help...
Dave

[jorge r]

Hi Dave

Here a picture:
http://img169.imageshack.us/img169/1824/mistress.jpg

Now I understand the clock setup. Thank you for the answer. I´ll use a friend´s oscilloscope and try to set it.

[loss1234]

this looks great

however...seeing as how i am partial to mn3207's...does anyone know if this will work with the mn3207 using the changes that same changes that were put up by moosapotamus (Sp?) for the ADA flanger?

anxious to try it on the breadboard!

thanks

[oldschoolanalog]

Here a picture:
http://img169.imageshack.us/img169/1824/mistress.jpg

From your pic it looks like R22(10k, by the output wire of the daughterboard) is not installed. Install it. I have that resistor soldered to the copper side of the board. That was done so the board could be installed taking up a minimum of height. Also; I can't see the component side of your daughterboard (my x-ray vision is not working today ); but make sure you are getting power to VCCa & VCCb. They are independent of each other. So, assuming the yellow wire is IN and the green wire is OUT and the white wires are CLK(+)and (-); everything looks like it's installed OK.

Now I understand the clock setup. Thank you for the answer. I'll use a friend's oscilloscope and try to set it.

...does anyone know if this will work with the mn3207...

Only one way to find out... Give it a try!
There's no reason it shouldn't work (famous last words )
Dave

[jorge r]

Dave

You are right.  I forgot to instal R22, a mistake in checking the schematics.
Now the effect appears beautifully. Very good!!!
I´m sorry about your x-ray vision. I hope you fix it soon      

Thank you again and for all.

     Jorge

[Just1More]

Hi

I'm going to have a crack at this - I'm just trying to all the info together as it seems to be scattered around a few places.  I've got two questions:

1) There are two different values proposed to replace C19 (47pF) in the clock circuitry.  Should it be changed to 22pF or 10pF?

  (plus 47pF capacitor in the clock circuitry /between ground and pin 3 of LM311 comparator/ would be halved to 22pF to double base clock frequency).

First, parts not used/installed:R23,R19,R11,R12,,D1,D2,C5,C9. Changes: new value & explanation in (parenthesis): R5(jumper), R17(47K, improved bias range), C19(10pf, This was done to raise the max clock f), R38(15K, As you raise the max clock f, the low f goes up w/it. This restored the low clock f), C14(Added 3n3 in parallel w/the existing 2n2 [5n5 total], the regen was way too "thin sounding". This "fattened" things up a bit), ...

2) Is there a complete schematic for the fill circuit with revisions?  If not I'll have a go at drawing one up.

Thanks

John

[oldschoolanalog]

Start w/10pF. That's what worked for me.  You can always tack on other caps (in parallel) if you want to experiment w/larger values.
Complete schematic w/revs?
Not to my knowledge. I just went w/what Tomas posted at the start of this thread.
All the Best!

[Just1More]

Thanks Dave 

[Thomeeque]

I'm going to have a crack at this...

Hi!

What exactly do you plan to do? Complete build of original (SAD1024) version of EM9V (Markus W. layout?) + this retrofit? Or you have already SAD1024 version completed and you need only SAD1024 replacement?

In the first case you may be interested in my EM3207 project. It looks like this at this moment:



It is again original 9V EM adapted for use of MN3207 chip this time , it is very close to the original, but it is slightly tweaked - besides inevitable clock circuitry adjustments (analogically to this retrofit) it's tweaked mainly to have unity gain (no volume drop compared to true-bypass) without need of additional amplification and there are few other minor changes (e.g. additional V_CC filtering for LFO section to lower danger of LFO ticking leaking into the audio signal via supply track).

As you can see from the pics, it's almost done but there's still some tweaking going on (it works, but it definitely needs some adjustments yet). I did few interesting findings in the process btw. (I'll get to them later here).

I did interrupted my work on this at this state before four months approximately (I've switched myself to other build), but I may return to it soon again - so if you don't need exact 9V EM and if you have some patience, you may wait for my results.

T.

[quarara]

flangers are blooming these days! Good to know!
Thomeeque, that board looks awesome!

[azrael]

^^whoa! Eagerly awaiting your results.