Low-Cut filter : 80 Hz (24dB/oct) – modifiable

Low frequency band : 30 Hz to 450 Hz – Bell or Shelf mode

Low Mid frequency band : 0.2kHz to 2 kHz – full Q Adjust

High Mid frequency band : 0.6kHz to 7kHz – full Q Adjust

High frequency band : 1.4kHz to 14kHz – Bell or Shelf mode

High-Cut filter : 8 kHz (24dB/oct) – modifiable


Maximum 15 dB of boost/cut gain per band (center detent)

High quality pots (TT Electronics and Alps Alpine)

THAT 1246 In- and THAT 1646 Outputstages


Its running on +16V/-16V in the 500 API Standard/ VPR Rack or in the GDIY 51X Rack

Here are some listening samples

Soundcloud SLQ51X


Build Guide
Build Guide


GDIY Help Thread
GDIY Help Thread

SLQ51X Brown

PriceFrom €259.84
Excluding Sales Tax
  • This is a Program Equalizer in 500 API Format, it's based on a classic styled 4000 Brown Equalizer. We added to this 4 Band Equalizer a Low and High Cut Filter to make it more flexible in Mixing or Recording situations. Same Electronic Circuit like with Orange Colour Caps.

    Improved Build - Easy Final Assembly, New Testpoints, BROWN Colour Caps (Formerly Orange)

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    • Free Standard Shipping in Europe on orders over 100€

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