Nava v1.2 - How to disable mixer? (SOLVED)

Hi,

I'm testing my first nava and I get a nasty noise from the mixer/master part. I use only individual outputs, so i decided to disconnect J14 and debug this part later.
I solved the noise issue, but all voices channels are mixed on each individual voice output (i.e.: on the BD i get all the other signals at lower levels).
After a look at 909 service manual, I decided isolate each output from the mixer by removing:
- R501 & 502 on the BD voice
- R504 & R505 on the SD voice
- ........
- ........
- R528 & R529 on the IDE voice
I still have the same issue, all active voices channels are mixed on each individual output. I don't understand how it is physically possible?

Thanks for your help!

Regards,

Nicolas

The voices are mixed on the IO board I think.

A too weak voltage transformer may be the issue producing noise in the audio.

You're right, some guys upgrade to 1.3A PSU and they get a quieter noise. The noise has many sources. That's why i try to short it by disable the mixer.

For example, on the single BD output (J11 on I/O board), I get a clean BD sound with all instruments muted. When I play HC ( J12 on I/O board), I get HC played at high level on the BD output also.
I removed all resistors wich can link J11, J12, J13 and J14 together. So how the clean HC signal from J12 can still goes trough J11 and play on my monitors?

I missed something when i watched the schematics, but I would like to know what.

Is there any mods on nava pcb which can explain this "virtual links"?

Hi,

Vincent told me to check out my connectors and he was right!

The ground on the jack plug is coming from the main board by J14-2 and 4. I was thinking this ground part was suplied by the I/O board directly.
So, I got the signal on each ouput through each sleeve in open loop.
I solved this problem by simply reconecting the J14-2 and 2 cables to the GND on the main board. Now i get a quiet and clean sound.

Regards,

Nicolas