Altec 1591A Mod

Altec 1591A Mod:

This Mod came about at the request of some customers who favored the fantastic sonic characteristics of the Altec 1591 Compressor, but found the excessive gain of the input stage to be a significant drawback in that it severely over-compressed normal level signals.

The Drawbacks  :  

1. To avoid over-compression the input level controls have to be set so low that fine control of level becomes difficult.  With the input levels set so low the output signal is just too noisy.
2. The release times are too long

The Solution :

1. A switch is added on the rear of the front  panel to select Normal or -22db  gain, (or rather stock or reduced, more reasonable gain).
2. The mic level pot is repurposed to be a compression threshold pot
3. A capacitor is changed to halve the release time, resulting in 0.25 and 0.75 seconds (instead of the original 0.5 and 1.5 seconds).  
4. When set for a large amount of compression at Normal gain the release times will be a bit longer so the “pumping” effect often used on drum overheads and room mics is still achievable.

See Details for more info.

(Price is for modification labor and parts.  Does not include unit to be modified.)

(Repairs not included)