Schematic Pronomic M-802 mixer

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RuudNL

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Apr 26, 2009
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In my studio I use some very cheap lousy crappy Pronomic M-802 mixers as 'personal headphone mixers'.
But recently I discovered that one of them had 15 dB(!) less gain from input to output.
Also the level meter indication is lower for the same input level.
Strange enough the gain from input to 'FX out' is the same as the other ones.
So I suspect there is something wrong with the (L/R) summing amplifier.
The whole thing is full of SMD components, so I would need a circuit diagram to find the problem.
I realize that I am asking for the (almost) impossible, but you never know...
Is there a circuit diagram of the Pronomic M-802 mixer around somewhere?
It would be a great help to have it!
(I asked Kirstein in Germany who sells the mixers, but I do not expect very much of it...)

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RuudNL

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Joined
Apr 26, 2009
Messages
2,418
Location
Haule / The Netherlands
Mmmm.... I just very carefully checked the component values in the mixers and it seems R218 and R219 are 362 (3.6K) in one mixer, but 363 (36K) in the other mixer. It might be that somebody in China needs a better magnifying glass!
 

RuudNL

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Joined
Apr 26, 2009
Messages
2,418
Location
Haule / The Netherlands
No idea if they have something to do with Behringer.
Anyway: the problem was fixed after replacing the 3.6K resistors by 36K resistors.
I suppose it says something about their quality control...
 
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