S-AOC Modular Optical Tube Compressor

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Holger

Well-known member
GDIY Supporter
Joined
Jun 11, 2006
Messages
893
Location
Hamburg, Germany
More modular madness: after building my modular tube pre amp I've finished an optical tube compressor. Essentially it's the famous AnalagOpticalCompressor published here ten years ago. I've built a couple of them in 19“ format and still find think that it is a wonderful unobtrusive compressor.
Unfortunately the Vactrols are not available anymore; I've hoarded a couple over the years. All Kubi mods are incorporated. The main difference to the original AOC is the 12.6V heaters. I'm using SMPS for heaters; 12.6V is easier to build since 6V SMPS are quite rare.
I/O TX are Sowters. The module is 10HP so I can put 8 channels in a standard Euro Rack.
The meter light goes off when in bypass. Front panel is printed (www.frontpanels.de).

frontsc.jpg


innensc.jpg
 
Wow  :eek:

I'm always surprised how people manage to squeeze pieces of 19" rack gear into this little format. Amazing
 
Superb quality build as always Holger.

I notice you have a cut out in the PCB where the tubes stand. What is the reason for this?

Cheers

Ian
 
I hope for a better heat/air flow here. I've taped a sensor on top of the solen and measured 39°C after a couple of hours (at 22°C room temperature) which is absolutely fine for a tube module.
sensor.jpg
 
Holger said:
I hope for a better heat/air flow here. I've taped a sensor on top of the solen and measured 39°C after a couple of hours (at 22°C room temperature) which is absolutely fine for a tube module.

Yes, anything less than 40 degrees is good.

I assume you are still using Fischer die cast modules? Do they have pierced vents top and bottom in the 10HP size?

Cheers

Ian
 
Holger said:
Yes, I'm using Fischer F-modules (IIRC)

OK. They are quite neat as long as you can put up with the 14.2mm space between the front panel left hand edge and the top surface of the PCB (which you probably can in a 2 inch wide module). In my home brew 1.4 inch modules my PCB top surface is just under 4mm from the left edge of the front panel giving me an extra 10mm height for components and the same additional front panel space.

One last question. 8 x 10HP = 80HP but a sub-rack is 84HP wide. How do you fill the gap?

Cheers

Ian
 
ruffrecords said:
OK. They are quite neat as long as you can put up with the 14.2mm space between the front panel left hand edge and the top surface of the PCB (which you probably can in a 2 inch wide module). In my home brew 1.4 inch modules my PCB top surface is just under 4mm from the left edge of the front panel giving me an extra 10mm height for components and the same additional front panel space.

One last question. 8 x 10HP = 80HP but a sub-rack is 84HP wide. How do you fill the gap?

Cheers

Ian
Once I'll have 8 modules I'll use a 4 HP blank panel.
 
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