9V Electric Mistress retrofit with MN3007

Started by Thomeeque, August 06, 2009, 06:57:44 AM

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Mugshot

Quote from: Fender3D on August 19, 2014, 05:59:34 AM
If you want 15V from your 78L15, you should feed it with more than 15V...



IIRC i simply subbed a 12-0-12 trafo (or was it 9-0-9?) for the busted 110V trafo it had. . i might as well use the outer lugs of the secondary coil of the trafo to go over/within the rated voltage the regulator needs.

QuoteAt a first glance MN's pins 2-6 show you have no clock, and bias voltage is way too low at pin 3

how should it behave? this is my first time using bucket brigades.
i am what i am, so are you.

Fender3D

You have no clock @ MN's pins 2-6 and @ 4013's pins 1-2. (you should have ~1/2 Vcc)

If you attach a scope probe there, you should have a square wave @ ~35KHz-1MHz (double these values if you messed with clock setting as you should with retrofit board..).

BBD's bias should be ~1/2Vcc. Check setting procedure for a proper hmm... setting

BTW:

you said:
Quotei currently have on bench an old Deluxe EM with a busted SAD1024

Are you sure it's SAD's fault or it's because the lack of clock?
"NOT FLAMMABLE" is not a challenge

Mugshot

Quote from: Fender3D on August 20, 2014, 05:51:37 AM
You have no clock @ MN's pins 2-6 and @ 4013's pins 1-2. (you should have ~1/2 Vcc)

If you attach a scope probe there, you should have a square wave @ ~35KHz-1MHz (double these values if you messed with clock setting as you should with retrofit board..).

BBD's bias should be ~1/2Vcc. Check setting procedure for a proper hmm... setting

BTW:

you said:
Quotei currently have on bench an old Deluxe EM with a busted SAD1024

Are you sure it's SAD's fault or it's because the lack of clock?

im guessing it's the BBD, mainly. i subbed the DEM's bbd in a working clone theory, and no nothing.

will check the biasing of the clock later.

i am what i am, so are you.

electronicnoobblog

Hello,

I'm not sure if here is a correct place to ask my question.

I have old MXR Flanger 117 - it was shoot to death via hi voltage spike from faulty power converter (external from 230V to 110V) in 80's.
I got this device without brain called SAD1024 and with notice - it was tried to fix but no positive result.

I done lot of searching and finally got Reticon SAD1024 but it is counterfeit (fake part) so i give up... the price for genuine is around 100USD looking at ebay.

Same time, anyway i went through flanger board  replacing all faulty IC-s - and finally manage to get on my scope 4 square clocks lines on SAD1024 socket (i'm unsure about frequency being correct because don't have anything to compare with).

I see in this topic about retrofitting SAD1024 by MN3007 and board.

I know this topic is to other effect but maybe someone know it possible to fit MN3007 in my use?

If someone of You can help me little bit i will be happy to read You

regards


12Bass

From the original MXR schematic, it appears that the SAD1024A is used with the two 512-stage sections in series, making a 1024-stage BBD.  So, it should be possible to use an MN3007 with some modifications.  The madbean Collosalus MXR 117 clone provides an example of how it can be done: http://www.madbeanpedals.com/projects/Collosalus/Collosalus2015.pdf
It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring. - Carl Sagan

Fender3D

"NOT FLAMMABLE" is not a challenge

electronicnoobblog

Quote from: 12Bass on July 11, 2015, 05:51:30 PM
From the original MXR schematic, it appears that the SAD1024A is used with the two 512-stage sections in series, making a 1024-stage BBD.  So, it should be possible to use an MN3007 with some modifications.  The madbean Collosalus MXR 117 clone provides an example of how it can be done: http://www.madbeanpedals.com/projects/Collosalus/Collosalus2015.pdf

I check on them but they don't have PCB-'s available.

After reading thread's at Your forum, right now i would go to replace whole PCB inside and left only original enclosure.

Quote from: Fender3D on July 11, 2015, 07:06:59 PM
http://www.diystompboxes.com/smfforum/index.php?topic=78741.0

I see Your schematic and i can see PCB silkscreen You posted here:



It was long time ago, but maybe You still have pcb etch-able layout and could share?

I believe that eatching and fitting new board inside would be the best option.


Regards

12Bass

Madbean shows the Collosalus PCB as available for $14.  I provided that link as a way of showing how the MN3007 could be used in place of the SAD1024A.  If you look carefully at the Collosalus schematic (or Fender3D's link), it is possible to see the necessary circuit modifications. 

Another option is to build a small MN3007 daughterboard which plugs into the existing BBD socket.  This only has a few components and is not that complicated, but it helps if you read through the previously linked thread and study the differences between the MN3007 and SAD1024A in order to understand the circuit.

In any case, there is no simple "plug and play" solution.  Some DIY work will be necessary to swap BBDs.....
It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring. - Carl Sagan