Soundcraft 600 Overhaul

pelagos

New member
Hi there

I have a Soundcraft 600 to "restore".

Its is basically working but needs a very good clean (pots, faders etc), and I would probably look to do some caps later if required.

I started by cleaning a couple of the input modules, the master module and 2 groups to get some signal through and see what the signal and noise level was like.

A couple of things I immediately noticed that any advice on were to start to 'troubleshoot' would be greatly appreciated.

The noise/hiss from the 'Control Room' outs and also the 'Studio' outs is quite bad - With no signal being played and just turning the volume up / down the hiss / noise is really bad - its the same in the Headphones.

Its also bad from the Group Outs

I run signal through 2 input modules (line level input) and then bussed to Group 1-2 and then to Pro Tools (via G/Outs into Focusrite Saffire interface). Sounds good but the hiss / noise is very bad when nothing is playing - it goes up and down when pushing the group faders up and down

But when I record a signal from the input channels line out (direct out - bypassing the master and group modules) to Pro Tools there is practically no noise at all.

So I assume the issue is with the master module and/or group modules or somewhere in between the input module and these?

Maybe the ribbon cable?? I have read that these can be problematic?

Hope this makes sense and any advise on where to start so I don't blindly go off on the wrong path would be great.

Thanks
pelagos
 
After a good clean the hiss / noise is greatly reduced.

I have an issue now I can resolve

Group 1 is very low in volume compared to other group channels


What I have tried:

Bussing different input channels to Group 1 (same issue so I don't think its to do with the input channels) - If I pan between Grp 1 and 2 on the same input channel the level goes up to normal for Group 2 (right) and back down low for Group 1 (left). This happens on all input channels.

Direct / Line outs from above test Input channels register good level

Swapping out different Group channels and setting the jumper to "1" to make it the Group 1 channel (same issue - Low volume - so I don't think it is related to a particular Group module strip)

Used different output connectors for Groups 1

The Tape In into Group 1 channel registers good level

Made new ribbon cable for Groups - same issue - although may have helped reduce the noise a bit.

If you really turn the volume up on the input channel you can get decent level to Group 1 but you have to really push it - Not sure what this points to




The above makes me think its in the Master Module but I am not sure were to start. I have tried to follow the circuit diagrams etc but get a bit confused and to me it does not look like there is any circuitry specific to Group 1 on the Master Module?? Although I am probably wrong...

Any advice on were to start would be great

Thanks
 
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