The Super Passive Equalizer is an dual channel, three-band passive equalizer with vacuum tube makeup gain stages. If features a uniquely flexible midrange band, and is capable of a wide set of curves.

Click the image or HERE to go to a page with detailed specifications and instructions.

There are a few of these units out in the wild, and I am currently updating some mechanical aspects of the design. Contact me if you are interested in demoing or purchasing one.

My take on the Diode Bridge Compressor. This unit is a stereo compressor with a single set of controls and a very fast sidechain. It is designed to excel on mix busses and groups.

Detalied information on features and operation can be found HERE

These units are built to order. Please get in touch via email if you are interested.

A one-off custom MIDI controller built for Elori Saxl in 2021. Inteded for use in her performance of "Blue" and other pieces.

It is built around a Teensy board, with all programming, analog design, machining, and woodworking by me.

I made this "R. P. Opto Comp" early on in the Covid-19 pandemic with parts that I had on hand at the shop. It is a mono optical compressor with a custom optical cell built into a stompbox that lives inside the chassis. There is a class-A amplifier at the makeup gain stage for a little color, but the circuit is otherwise a no-nonsense op-amp implementation. The chassis and power supply are recycled from an old Rane crossover that I bought from my neighbors a number of years ago. I later found out it was a kind of rare and sought-after unit. Alas. This compressor was sold to a good friend in 2021.

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 customtubeconsoles.com

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.

Compressor 04 is a stereo diodge bridge compressor with gain reduction circuit similar to Neve compressors, but with unique op-amp circuitry and a completely different sidechain. a combination of switched and variable time constants allow for a wide range of attack and release profile. This is the first prototype of the commercially available diode bridge compressor.       

These are the first SPEQ Prototypes that I made. They have a slightly less refined set of curves than my commercial version but are basically the same circuit. At 5u high and 1.6" wide, they are a much smaller form factor than the commercial version. They rely on an extrenal power supply. Eventually, they will be integrated into a larger modular system. I use them regularly in my engineering work.

This amp used to be a Kalamazoo Model 2. The Model 2 has a lovely form factor but doesn't sound very interesting. So, I gutted mine completely, reused the sockets, tubes and transformers, and built high-gain Fender/Marshall 5-watt Class-A amplifier into the chassis.

It features a full Twin Reverb-style tonestack with an extra switch to shift the treble frequency higher, which also affects the mid control. The mid control has a greater range of control, so you can make the curves less "scooped" than a Fender.

The Amp features a gain control, and two separate output controls, one for the DI output and one for the speaker. Both outputs have jacks, so any speaker can be used.

I made this Extension Cabinet for a 10" Jensen ceramic speaker I had lying around. The cabinet is made from maple plywood and remains of the old formica table saw outfeed table at the Museum at FIT, where I was working at the time. The edgebanding is all hand-cut and mitered, and the finish is pure, polished shellac.

I designed the handle to lie flush with the top if desired. It is a simple construction made of leather and aluminum. The leather is easily replaceable when it inevatbly fails down the road.

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.

The internal construction is a mix of turret board and point-to-point wiring.

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 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.

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 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 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.

This Super Duper 2-in-1 is a clone of the Zvex pedal with a slight modification - the master volume only applies to the second booster, not both boosters.

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 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 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 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 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.