Yet another GSSL build!!! (codename DSL4000+)

[dtrax]

So, I'm starting another SSL bus compressor build. The first time around I went with Ruckus' SB4000 – a fantastic build. Sounds great, so I decided to make another. However, for this I wanted to do something different to have a bit of variety so I'm using a GSSL pcb as a starting point. I still have to flesh out some of my ideas, but at the moment I'm considering some rotary switches for stepped control over threshold and make-up gain. The schemo calls for 50k linear pots, so I've been doing some calculations on the resistor values. I thiiiiink I'm on the right track but I'm still a rookie at all of this, so would you be so kind as to check over my work?

Below are my calculations, and the nearest standard resistor value. Position 1 would be fully counter clockwise fyi.

                Calc            Std Value
pos 1       0           0
pos 2       4545.45     4k53
pos 3       9090.91     9k09
pos 4       13636.36   13k7
pos 5       18181.82  18k2
pos 6       22727.27  22k6
pos 7       27272.73  27k4
pos 8       31818.18  31k6
pos 9       36363.64  36k5
pos 10        40909.09      41k2
pos 11        45454.55      45k3
pos 12        50000      49k9

Obviously using a 12 position rotary is rather course, but the point is to make recall exact for re-mixes. For fine adjustment, I simply use Master tracks in Pro Tools for all my bus sends to my outboard gear.

Other ideas/mods I have (which I'll post updates in the thread as the build progresses):
VU Meter, for switching between GR / Output / Input
Stereo/Mono sidechain – a must, and obviously switchable
Trannies on input and ouput. I'm going to start with some Edcor's, well, because they're VERY economical, and sound good to boot. But the point is, if the trannies end up not making a shit bit of difference, I won't be out a few hundred bucks.
1:5 and 20:1 Ratios – I'll build a daughter board for this.
50ms Release time – To make room on the pcb I'll probably omit the 1.2sec setting. I never use it anyway.

 

[gemini86]

If you're going for 50K LINEAR, then you just divide 50K by the number of steps... So for a 12 position rotary, you would have 11 resistors... 50K divided by 11 = 4.5K or nearest E12 standard is 4.7K.

 

[pucho812]

correct to get linear values divide the value by the number of steps. If you really want to go for it do a 24 position switch . or skip all that and put in  a switch with detents.

 

[dtrax]

Cool, thanks guys. I'm going with 12 step switch to start with, just because it's easier to wire and I'm doing the front panel labeling myself, so I don't really feel like being bothered with 24 markings. Eh, perhaps a bit lazy, but my work around for "fine tuning" is using ProTools' master faders to get into the "sweet spot". It just makes recall extremely accurate. In any event, parts have been ordered, and will be here this week. Just waiting on the pcbs from Gustav (GSSL) and Expat (VU, CRC and Stereo SC boards). I'm skipping the SC filters for this build; my SB4000 has that covered. Plus, I don't use them as much as I thought I would.  :-\

 

[martthie_08]

I use my GSSL as a hardware insert in ProTools too and don't even bother with the Threshold and Makeup Gain pots anymore, just leave them fixed (make-up gain at 0) and level with the Trim plugin. Mostly it will just be tickling the Gain Reduction needle, that works great for me!