Blah Blah Cafe, the Jean-Michel Jarre forum

[olivier_0001]

somebody would have shematics from the famous MP7. I would like investigate to mod my MP7 with extra input : time syncro.

thx !

[radek tymecki]

hi there! keep me informed about mods i'd like to perform those also

[olivier_0001]

thanks Radek

I just see schematic and propably the oscillator master (MOSC) is the key for this mod.
also bypass the start/stop key, this bistable given good voltage for all divider flip flop 1...6

Just time needed, I let you know when is 100% functional

[radek tymecki]

ok btw... I have two minipopses... but one doesn't work properly. when i press start/stop button the rhytm doesn't start. U know what can be the reason?

[olivier_0001]

send me , and I can repair it

I see two reason for rythm don't start :

- bistable (2 transistor after the start stop switch) is defect
when start button is pressed, this circuit allow all the six flip flop's
Flip flop are divider ryhtm from the main oscillator

- and second : the master oscillator is defect, you can check with a oscilloscope or a led + R

do you have electronic stuff to check signal ?

[radek tymecki]

no

but You can make a photo and show me what can be changed

[matt222]

Make a syncable MP7 and I'll give you a grand for it.

[Cryptic Era]

Thanks for the schematic Radek, I've had a bad quality scan for a few years and yours is crystal clear

I'm guessing that mods, if any, can also be done to the Univox SR-95 (MP7 clone). I say clone losely, because some of the rhythms are different - i.e. when combining Beguine & Slow Rock buttons for those Oxygene 2 and 4 rhythms, the single 'Noise Hit' / Open Hi-Hat / Tishhhh sound is missing (oh, you know ! ... that single Tishhhhh hit in every bar

... that could just be my SR95 unit of course as the tones vary on probably every unit.
My Quijada sound wanders in pitch by about 1 octave whilst the rhythms play, hence the need for a good schematic.

I'm new to the forum and loving the posts - Thanks all.

[matt222]

Welcome Simon.

[olivier_0001]

welcome simon,

if you look the excellent shematic from Radek , you can see the pot for adjust the ptich of Quijada.

Look these both info about trimpot



and individual sound output



External Syncro project for MP7 : STEP 2
functionnal with midi kit (MIDI IN - logical output), I create pulse from sequencer for trigg the master oscillator transistor. VERY GOOD RESULT, SAME of the original but with always the exact TEMPO !!!

STEP 3 trying to use directly the syncro signal SMPTE ??? to test......

[radek tymecki]

I was thinking about sth...

As You can see there are trimpots for adjusting volume/pitches of some sounds.... Maybe it could be a good idea with creating small 16x16 matrix for own rhytm creating + switches&pots for adjusting volume level or setting it to factory?

i'm interested in midyfying !!

[olivier_0001]

Last year, I'm doing long time project for midifying the MP7.
The project use a kit with multi digital output command by key number 0..127 - on/off
Between this midikit and the MP7 sound board, it was a special little transistor whos adapt the digital signal to the sound board, like the sequencer board from MP7

It was functionnal but very very cable, two external board... finally I'm decided to stop with this project because, the original design of minipops is very 'destroy'

For me the best solution is keeping the internal sequencer with a special extra input forsyncronizing the tempo.

Ideal is to have two MP7, one original and second for midifying or extract the sound board with a matrix like Radek says. A little digisequencer

i see you mail Radek

[Cryptic Era]

Thanks for the circuit board images Olivier ! - That'll also help.

Because the Quijada pitch changes by itself randomly, I'm guessing a dry solder joint near the pitch pot or perhaps the pot needs some switch cleaner ?

Mine is an America unit (110v). Do you know if the power can be changed to 220V easily by modding/adjusting the fuse assembly ? I'm currently using a power convertor at the moment.

Did the MP7 or SR95 ever actually come with an owners manual ?
(no doubt a very small one if it did)

[olivier_0001]

Like you say; randomly problem is probably due to a bad contact.

POSSIBILITIES ONE
For the transfo using 110 - 220 V, many transfo is original with the both possbilities.
then one cable is not connected in function of the country...

i'm looking mine MP7 (KEIO MINIPOS - NOT SR95) primary wires :

white : 0V
yellow : 220V
red and blue : interconnected

If you decide to test it, secondary voltage have two wires, BEFORE DISCONNECT one of them.
Compare the secondary voltage with you adaptator transfo and after the mod.
I think the secondary (output voltage) is 20...25 V

About 220V fuses, your existing fuse value must be divided per 2
if you have 200 mA - 110V = = 100 mA @ 220 V ok ?

POSSIBILITIES TWO
Replace the original transfo with a standard, you just must know the output voltage.
miniopos consommation is very low 500 mA ? at 20 V --> 10 VA
change the fuse like upper explication

GOOD LUCK !!!

[radek tymecki]

OK so here can we make kinda official minipops thread huh ?? we can describe here howto DIY that box or try to fix problems...

I'm gonna start here I have 2 MP7's.

First one has some strange problems:
- some sounds have very low volume. Trying messing with trimmers - no result. The volume of hihats, cy's and few others is about 30% of max

Second one:
- when I press start button nothing happens