Soundcraft 600 fixer upper

[FarisElek]

Well, it looks the part. My memory is not so clear about the lever.

No, there is nothing to gain here. You may try replacing IC2 & 4 on the Master module, though.
I assume you have the Standard output modules (one fader, two tape returns); then you may try replacing IC2.
In both cases, I don't think the difference would be spectacular.

Do you mean for the summing amps? I don't remember a version of the 600 that doesn't have transamp summing amps... Can you post a link to such mods?

Here is the thread of this being discussed.

https://gearspace.com/board/geekzone/262911-quot-trans-amp-quot-mic-pre-mod.html
On the schematic it says "Mic Amp circuit added" to Issue 6

 

[abbey road d enfer]

On the schematic it says "Mic Amp circuit added" to Issue 6

Do you have the schemo of your actual mic pre? I didn't remember there was such a change of topology.
I wouldn't recommend the mod suggested by JW. Only one half qualifies as a transamp. Stay away from it.

 

[FarisElek]

Do you have the schemo of your actual mic pre? I didn't remember there was such a change of topology.
I wouldn't recommend the mod suggested by JW. Only one half qualifies as a transamp. Stay away from it.

I've only been able to find this later schematic unfortunately.

 

[expat]

Forgetting JW's mod, can't you copy what's in the V6 schematics? I thought it included this update. Well, i hope so anyway, since i have a V6. ;-p

 

[abbey road d enfer]

I've unearthed this previous thread
https://groupdiy.com/threads/soundcraft-500-600-measurement-and-improve.63053/One of the problems is that it has not been done following a scientific method, i.e. several variables have been changes so it's difficult to know what improvement is the result of what change.
However, some of these changes have been experimented elsewhere independantly, so we can more or less attribute:

• Noise improvement to the change of input transistors
• Better LF response and THD improvement to oversized/newer technology coupling caps
  
  I don't believe any noticeable improvement results from the JW mod.

 

[FarisElek]

Forgetting JW's mod, can't you copy what's in the V6 schematics? I thought it included this update. Well, i hope so anyway, since i have a V6. ;-p

I can, but I don't know exactly what has changed so I'd have to examine my boards very closely and then consider how best to implement changes since I believe there is another opamp added amongst other things. Something I have at most 45 minutes a day to work until who knows when. I'll look into it someday unless someone has done the work already and can tell me what to do.

Loving the rehabbed board as-is right now so it's fine.

Update: Got a CPS450 for cheap and it's been like a dream come for noise levels compared to the S500 I had gotten it with.