500 Series P501 Audio Processor

The P501 provides a high quality tracking solution in a single width 500 Series compatible module.


The only 'channel strip' solution for the lunchbox® with mic pre/hi pass filter/compressor/limiter and dual bargraph metering.


Flexible choice of mic, instrument and line level inputs feeding the class leader in tracking compressors featuring the multistage peakride system; wonderfully smooth on vocals and great for tightening up bass lines.


Check out the great features below.

Compatible with the API™ 500 Series modular format which allows a number of audio modules to be plugged into rack frames such as the API™ 6-slot Lunchbox and 10-slot 500VPR rackframe).


Front end

Ultrawide 60kHz bandwidth microphone input with 72dB of gain.

High Impedance instrument input.

Balanced Line Input.

Really easy to use single gain knob for all three inputs.

Switchable 80Hz high pass filter.



The best tracking compressor for vocals on the market. Derived from the original Safe Sound P1 design using a multistage sidechain named peakride, it provides tightly controlled vocal compression with perfect transparency. A 100% original hardware design in today's world of grey copycat software emulations.

Fully adjustable THRESHOLD, RATIO and ATTACK

'Follow audio' controlled release time.

Auto gain make-up allows you to increase gain reduction 'on the fly' without having to constantly re-adjust the output level.



Switchable fast limiter for ultimate protection during tracking or push it hard as a great dynamic effect especially on bass and drums. The limiter features dynamic adjustment of attack time, so the faster the audio front edge, the faster the limiter reacts. So fast clipping protection when tracking but also very useful as a creative tool in its own right when pushed into heavy levels of limiting.


Output Stage

Balanced output stage with +22dBu drive capability.

±15dB output gain control (post limiter) allows perfect level matching to your recording device.

On-board LED bargraph metering for audio level and gain reduction.