Mid Tom: low volume. Hi Tom: Overdriven/ distorted...

nice find indeed, gonna check it in my nava in the evening

thanks peskado!
to bad i don't have a stash of parts, so i'll have to order some...

I spend few hours for comparing schematics
Found few differences, I want make thread with this info

Ah! So the 909 has a 100k at r124?

Yes! In case anyone else wanted to mess around with the schematics, Kazper linked me to this the other day
http://www.synthage.com/downloads/TR-909.pdf

more errors here

viewtopic.php?f=24&t=970

Don't bother changing R124, I just did and it doesn't solve the volume issue

I just post difference between 2 schematics
I sent message to friend and asked about toms level.
He have tr9090

decoder303 wrote:so here are my measurements.

first measurement: low tom (blue) and mid tom (red) accent signal at IC114 (pin12 and pin13):

second measurement: accent signal after the OP amp at the accent testpoint, again low tom and mid tom:

third measurement: env 1 testpoint low tom (blue) mid tom (red):

fourth measurement: env2 testpoint low tom (blue) mid tom (red):

fifth meauserment: env3 testpoint low tom (blue) and mid tom (red).

and last measurement the low and mid tom at the outputs, I accidently swapped the probes, red is low tom here:

the osc signals have the same level on both the low and mid tom. To me it seems that the problem is already at the multiplexer? Might also be an option to change the gain of the op amp circuit of the mid tom? Gonna give this a try later

Vincent welcome back from your vacation, if you find some time, what are your thoughts on the measurements? I would appreciate some feedback here, since the same problem seems to be apparent at other Navas two, it would be nice to find the issue here.

Dear,

We are working on the firmware to solve the Mid tom low level.
Be patient, a firmware update will be available soon.

Best regards,
e-licktronic