Altec 1591A Mod

Altec 1591A Mod

Altec 1591A Mod

(click pic to enlarge)



Altec 1591A mod Chassis Inside view


This pic shows the gain switch added to the rear of the VU meter.  Front panel is easy to open so switch is readily accessible.   On the left a small plastic bag can be seen that holds some of the pre-mod parts, just in case one wants to go back to stock.


Altec 1591A Mod

Altec 1591A mod showing close up of gain switch

(click pic to enlarge)


Altec 1591A mod close up on gain switch



This pic shows a close up of the gain switch.  “NORM” position is meant for  use with line level signals.  “+22 BOOST” is meant for use when input signal is unusually low or to get back to the mega compression of an umodded 1591A.




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  angry:  

  1. To avoid over-compression the input level controls are 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 laugh:

  1. A switch is added on the rear of the front  panel to select Normal or +22db  gain, (or rather reduced gain or stock 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 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.

  • Product Code: WPA-Altec-1591A-mod
  • Availability: In Stock
  • $190.00

Tags: Mod, Altec