I’ve done 24 channels so far. Also i have recapped using Nichicon Muze KZ and Elna SILMIC II caps in some channels as well as used Wima film caps in parallel to bypass the Electrolytics. there are a large number of the Electrolytic caps ( probably like 100 or so on a channel! ) and many had to be bypassed. Transients are amazing now on the film cap bypassed channels, snares with more pop, overheads with much more accurate sounding resolve and transients. I thought that the chips were the limiting factor in this console and while i have had positive results with a few different chip swaps ( especially swapping 5532, & 33078 with the fabulous LME49720 chips in certain sections) the caps and bypassing some of them with small value film caps made a bigger difference.

the ELNA SILMIC II caps sound great in the coupling stages. i have a bunch of channels with Panasonic FM caps as well to compare, and while they ( the Panasonic FM’s) sound very good, they are not in the same league as the SILMIC II caps.

I do have linear PS supplies with my console. Honestly , well designed switching supplies are not bad at all. Unless they dropped the ball on design, your switching i would leave them alone (or do a recap at the very least) .

Dont worry about the consumption of the linear supplies, its not that bad to be honest.

Congrats for these mods, and huge thanks for sharing them with us, I’m definitely willing to try them !

Did you do the DC servo mod yet ?

Another very big upgrade for a S12 would be to replace the noisy switching PS by linear ones (I think only Paul’s desk and Rainbow’s desk have linear PS’s), but that might not be so cheap, and of course there’s the power consumption and heat!

I have another project brewing as well. i will probably be making some little pc boards to switch the gazillion coupling cap stages for the channel strips to DC servo . which means you can remove all dc blocking capacitors from the channel/signal path and replace with the DC servo circuit .

DC servo circuits balance the DC offset so your chips are running perfectly balanced instead of using blocking capacitors which just block the DC out like a filter. This will clean up the signal path immensely (GOD only know how many blocking caps there are in even one channel of the S12) Of course you can do some channels and leave others alone for different tones. If you are like me , you short load your console (dont run all of your channels) which means you could easily have 8-16 channels of dc servo channels and the rest stock or whatever you need, just plug in the ones you want for a particular project. Let me know if you guys are interested in this, because i can put a larger order in for the little custom designed pc boards. They wont be very expensive. I cant leave well enough alone!

After that i want to clean up the high band eq a bit (which maybe just replacing a chip with the discrete mod above) , i’ll dig into that later.