Download a short piece from RADIO-ELECTRONICS, 1950, on the subject of a DIY audio-compressor:
DOWNLOAD: DiodeCompressor1950
This promises to be an interesting unit. It’s designed (like a Shure Level-Loc) for Mic-Level-In, Mic-Level-Out, but that could pretty easily be changed for balanced-line operation by omitting the first 12AT7 stage and using a modest step-up transformer (maybe 1:3 or 1:5) going into the input level pot, and then adding another output stage and output transformer. (Since 1/2 of the 2nd AT7 is unused, I am thinking: eliminate one of the 12AT7s entirely, build this circuit minus the first stage using one 12AT7, and then add the output stage from the Altec 1566). The unit promises to add distortion, and there is some sort of low-pass network before the 3rd grid that will also need some sort of variable components added in order to control the quality of that distortion. My biggest question, though: will plain ‘ole IN4007 Diodes work in the circuit? I plan to build this thing soon and all questions will be answered… always looking for new (old) sources of novel grit+crunch….
4 replies on “Novel Vacuum Tube / Diode Compressor: 1950”
Very interesting article.
Any update?
no, i have not,,, it’s on the list though! It would be at the very least an interesting ‘colour box’ for the studio. c.
Hi Chris, Good news
I found in web blog about signal clipper that hum radio guys wrote
ORBAN specified diodes those used in signal clipper eqmt
Those basically low voltage switching diodes
But for the audio signal clipper ORBAN specified below
Multi band clipper diode > 1N4148 or 1N914
Safety clipper diode > 1N5711 or 1N5712
Got another info from custom stomp pedel maker
below is what he said
Yes 1N4007 or 4006 can be used
As long as if it’s sound good to your ears
If sounds bad or distort or squished too much
You might have to change around with other
What about Coil trans next to R1?
I wonder if one could use a tube with 2 diodes and a triode in this circuit to replace the first tube and the diode pair? Something like a 12AV6 (1/2 of a 12AX7 + two diodes) or something similar… Perhaps this approach could be used to eliminate the entire front end of the circuit as shown and still provide similar benefits…