Modular Line Processor 1

Modular Line Processor 01 is a line-level audio processor assembled from discrete modules that share a standard hardware configuration and power supply. Audio signals are routed via 3.5 millimeter unbalanced connections, similar to the eurorack standard. This allows for maximum control over gain staging and sonic manipulation. It includes master bypass switches for proper evaluation. It currently includes:

Passive Equalizer 01 - A pair of all-passive Pultec-style equalizers with an additional mid control. Built using boards and design by Ian of

High Impedance General Amplifier - Dual high impedance, medium gain amplifier for use with Passive Equalizers 01 and as general utility amplifiers.

Compressor 02 - Fet-based mono compressor with attack and release controls and a switch that kicks it into "smash" mode

Compressor 03 - Optical-cell-based mono compressor a la the LAxA compressors

Studer 3-band Equalizers - A clone of the channel equalizer from the Studer 96x series consoles.

Stereo Diode Clipper 01 - A dual clipper allowing for independent control of threshold and ratio for each half of the waveform. Featuring ganged controls for stereo use and the option to switch between germanium diodes and LEDS for clipping. The LED's are panel mounted and light when active.

Dual Vacuum Tube Microphone Preamplifier 1

Vacuum Tube Preamplifier 02 is a dual, Class A vacuum tube preamplifier intended bringing low-level, low-impedance balanced signals up to balanced line level. It offers control over gain, phase reverse, 20db pad, and 48v phantom power on the front panel. Inputs and outputs are transformer balanced. It also features high-impedance direct inputs for instrument use.

Vacuum Tube Condenser Microphone

Vacuum Tube Microphone 01 is a large-diaphragm condenser microphone that uses a transformer-coupled vacuum tube for amplification and impedance matching. It features an edge-terminated capsule and accomodates cardiod and omni patterns via an internal switch. It is built into the shell of a not-worth-repairing MXL V76t.

Compressor 01

Compressor 01 is an analog compressor that uses an optical cell for gain reduction. It is derived from the design of the well-known LA-2A compressor, substituting contemporary monolithic opamps for the circuit blocks powered by vacuum tubes in the original, and LED’s for the rectifier and electroluminescent panel. The optical cell is assembled in a cut-down 35mm film container.

Dual Vacuum Tube Line Amplifier

Vacuum Tube Line Amplifier 01 is a dual, single stage Class A vacuum tube amplifier built into the chassis of a voltmeter, using some of the original components. It features two high-impedance inputs with individual input attenuation, and two high-impedance outputs.

Vacuum Tube Preamplifier 01

Vacuum Tube Preamplifier 01 is a high-gain, high-impedance mono amplifier. It is a modified voltmeter repurposed as an audio amplifier. To facilitate input, it is accompanied by an external box that contains a typical mic preamp front end - XLR, transformer, pad, and 48v switches - along with a 1/4" input for instrument use.

RCA Power Amplifier 1

RCA Power Amplifier 01 is a vacuum tube amplifier recycled from a non-functioning film projector and housed in a custom case. It features a high-impedance input, tilt-style tone knob, and 15 watt power amplifier.

Passive Treble control

Passive Equalizer 02 is a treble control. It is capable of boosting up to a 6db high shelf and attenuating down to a 6db/Octave low pass filter. It has five selectable frequencies. Input impedance is 5 kilohms. It is completely passive and requires a high-impedance makeup amplifier with at least 6db of gain to achieve unity output.

Power Supply 01

Power Supply 01 is intended for use with vacuum tube amplifiers. It produces a 300 VDC B+ voltage, a hum-balanced 6.3 VAC heater voltage, and a regulated 48 VDC voltage intended for the phantom powering of microphones. It has two parallel 7-pin output jacks and a potentiometer in the heater circuit for hum-balancing.

Power Supply 02

Power Supply 02 is a 10-watt dual voltage-regulated power supply. Voltage is adjustable internally via trimpots, but it is intended to operate at at a fixed ±16 Volts DC. Used to power Modular Line Processor 01 and/or Compressor 01

Power Supply 03

Power Supply 03 is intended for use with vacuum-tube-powered microphones. It produces a 100 VDC B+ voltage and a passively-filtered 6 VDC heater voltage.


Audio Amplifier 01

Audio Amplifiers 01 are stereo amplifiers built around Sure Audio boards that use tripath class D chips and put out ~8 watts per channel into 4 Ohms. They feature 10 kilohm input impedanceand via passive attenuators on the front end.