500 series without compromise

The FET/500 series of ANALOG compressors is based on the famous 2U rack compressors designed in the early 60’s. Finally, the circuit has been faithfully recreated in 500 series format maintaining its classic sound, fully discrete audio path, while adding new features. The circuit was adapted into 500 series format by Mako Natsume. Mako has years of PCB layout experience and spent six years developing the FET/500 concept. The FET/500 series of analog FET Compressors is available exclusively through Hairball Audio.

Classic circuit without Compromise:
The FET/500 is the same FET Compressor found in the MNATS rack version sold at Hairball Audio. The circuit is left unaltered and the full sized transformers are used. This is true classic compression without compromise.

Ratio Settings:
The FET/500 features all the classic ratios including All Buttons In (SLAM) mode. It also features a 2:1 compression mode which has become our favorite.

Dual LED Metering:
The dual meter circuit displays both gain reduction metering (top) and +4 output metering (bottom) with a +16dBu peak indicator. The gain reduction meter provides a far more accurate display of gain reduction, attack, and release, than even the highest quality analog meters.

True Bypass:
In addition to the classic “GR Off” which disables gain reduction but still passes the signal through the entire audio path, the FET/500 also features a true bypass switch. True bypass removes the compressor from the chain entirely.

Stereo Linking:
The FET/500 features front panel stereo linking jack, linking is achieved by connecting the 1/8″ front panel jacks on each unit with a male-male stereo 1/8″ cable. For stereo linking to work properly FETs in each unit should be closely matched.

True Linear Power Supply:
Many classic circuits require a 24-30VDC supply rail for the crucial audio signal supply, the FET compressor requires a 30VDC rail. This is problematic with 500 series which operates on a +/- 16VDC supply. Previous designs use a voltage converter to double the +16VDC rail to create the 30V DC rail. This is also problematic as voltage converters are VERY noisy. The FET/500 on the other hand uses a different approach. Mako created a PCB that uses the -16VDC rail as audio ground, creating the required voltage rail without any compromise. The DC/DC conversion is left for the -10VDC rail where it is filtered and used for non-audio purposes.

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