9V Electric Mistress retrofit with MN3007

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

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Thomeeque

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azrael

Gosh, I need to get an o-scope so I can bias this thing. That's the only reason I haven't built one. :(

12Bass

Quote from: azrael on July 28, 2010, 01:57:41 AM
Gosh, I need to get an o-scope so I can bias this thing. That's the only reason I haven't built one. :(

Although helpful, it is not necessary.  BBD bias can be adjusted by ear.
It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring. - Carl Sagan

theehman

Quote from: 12Bass on July 28, 2010, 08:30:49 AM
Quote from: azrael on July 28, 2010, 01:57:41 AM
Gosh, I need to get an o-scope so I can bias this thing. That's the only reason I haven't built one. :(

Although helpful, it is not necessary.  BBD bias can be adjusted by ear.

+1.  In all the years I've been doing repairs, I've always biased BBDs by ear.
Ron Neely II
Electro-Harmonix info: http://electroharmonix.vintageusaguitars.com
Home of RonSound effects: http://www.ronsound.com
fx schematics and repairs

JRM

#124
Quote from: jorge r on May 09, 2010, 06:08:45 PM
Hello

I've made a new layout joining both Gaussmarkov's layout and daughter-board by Tomas (Tomeeque).
It's already tested and working. I Used the mods suggested by Dave W.(oldschoolanalog).
Schematics later (I'm lazy now  ;D)

http://www.4shared.com/document/wPcCxA3H/Mistress_9v_MN3007.html

I hope you like it !




If I got it right, to change this PCB from a 3007 to a more adequate 3207 just requires a change on pins 1 and 5, modify the values of R9 and R10 (don't imagine the right values) and conect R11 to Vcc instead of ground. I'll try to do an update drqwing of that.

DLC86

Quote from: JRM on September 15, 2010, 11:56:18 AM
If I got it right, to change this PCB from a 3007 to a more adequate 3207 just requires a change on pins 1 and 5, modify the values of R9 and R10 (don't imagine the right values) and conect R11 to Vcc instead of ground. I'll try to do an update drqwing of that.
You just have to exchange R9 and R10 (in the retrofit layout), for the other stuff you're right  ;)

JRM

OK. The resistors it's easy: just swap R9 with R10 and connect R11 the other way around. For the IC: I was reading Panasonic's MN3207 and 3007 datasheets and found out that they have exactly the same terminal assignments. pdf files are too large to upload but it goes like this:
1-GND    8-OUT2
2-CP1     7-OUT1
3-IN       6-CP2
4-Vgg     5-Vdd

If this is correct we don't have to invert the IC. I'm right or did I miss something?

StephenGiles

Quote from: theehman on July 28, 2010, 08:32:08 AM
Quote from: 12Bass on July 28, 2010, 08:30:49 AM
Quote from: azrael on July 28, 2010, 01:57:41 AM
Gosh, I need to get an o-scope so I can bias this thing. That's the only reason I haven't built one. :(

Although helpful, it is not necessary.  BBD bias can be adjusted by ear.

+1.  In all the years I've been doing repairs, I've always biased BBDs by ear.

The sound heard out of the BBD when adjusting the bias trim should be nothing/distortion/clear/distortion/nothing, so set it at a point where clear sound is heard.
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

DLC86

Quote from: JRM on September 16, 2010, 04:40:28 AM
OK. The resistors it's easy: just swap R9 with R10 and connect R11 the other way around. For the IC: I was reading Panasonic's MN3207 and 3007 datasheets and found out that they have exactly the same terminal assignments. pdf files are too large to upload but it goes like this:
1-GND    8-OUT2
2-CP1     7-OUT1
3-IN       6-CP2
4-Vgg     5-Vdd

If this is correct we don't have to invert the IC. I'm right or did I miss something?

You can find the answer on page 3 of this topic. The 2 ICs have the same pinout but MN3007 has P-channel FET while MN3207 has N-channel FET so you have to exchange just pins 1 & 5 to compensate this difference. You can compare my retrofit for MN3207 with the original 3007 one to see the changes I did

JRM

OK! It was just an English issue (not my mother language). When I saw change pins 1 and 5 I thought the chips were different (kind of mirror image). Know it's even easier than I tougth. Thanks a lot.

jorge r

Hello

This is the new version with output boster and the complete schematic.:





The link for PDF:

http://www.4shared.com/document/8sQgOJF0/Mistress_MN3007_English.html

Tested and working.I  hope you like it.


oldschoolanalog

Nice work jorge! :icon_cool:
One suggestion/BIG favor... Could you please put some send & return pads for the TZF option on the board? Just refer to the original markusw schematic/PDF for placement. I have a TZF board on the way and want to use this layout for the main flanger circuit. If all goes well then maybe the EM & TZF boards can be incorporated on one PCB.
Thanks!
Mystery lounge. No tables, chairs or waiters here. In fact, we're all quite alone.

jorge r

Quote from: oldschoolanalog on September 20, 2010, 05:12:10 PM
Could you please put some send & return pads for the TZF option on the board?

Yes , will be a pleasure. Tomorrow I'll do it !


oldschoolanalog

Mystery lounge. No tables, chairs or waiters here. In fact, we're all quite alone.

Ummagumma


jorge r

I can do it with 3207, but I canĀ“t test it and I need to read how to do it, so takes more time...

JRM

I was trying to base the 3207 pcb layout on jorge's 3007 but I've discovered that the 3207 scheme (on the 1st or 2nd page of this thread) is not exactly the same, with several changes and specialy with less components (8 resistors and 3 caps if I've counted correctly). 3007 scheme is nearer the original SAD1024 scheme. Can somebody explain me why?

jorge r

Hi
I 've exchanged pins 1 & 5 in the layout. Is that enought?
If someone wants to try...

http://www.4shared.com/document/ZahcEM1H/EM_3207_test.html

IT IS NOT TESTED!!!