ADDAC System ADDAC200PI (2015–)

A send/return module for pedals that sits between a modular and a pedalboard and makes you choose neither.

Overview

You know that moment when you’ve got a sweet Eurorack rig humming, a gorgeous Mutron III on the floor, and you just want to patch it in without frying your modules or losing half your signal? That’s where the ADDAC200PI steps in—not with fanfare, but with quiet competence. It doesn’t generate sound, modulate it, or mangle it. Instead, it does something rarer in the modular world: it gets out of the way. This is a dual-channel pedal integrator, built to bridge the impedance and level gap between modular gear and guitar pedals. And it does it with surgical precision, zero fuss, and a footprint so small it barely registers on your rack.

The module is 4HP wide. Each channel handles send and return independently, with level scaling. The send side attenuates modular-level signals (around ±5V) down to instrument level (roughly -10dBV), which is what pedals expect. On the return, it boosts the weaker pedal output back up to modular levels, so filters, mixers, and VCAs don't starve. That means no noise floor creeping in and no clipping on the way out.

It's marketed as a pedal interface, but owners use it for other jobs. Some bring line-level gear like drum machines or audio interfaces into the rack. Others use it as a compact headphone amp (one channel, mono, but it works). It shows up in 900+ ModularGrid racks, because it solves a problem most modules ignore.

Specifications

Manufacturer	ADDAC System
Production Years	2015–
Original Price	€100 / $120–134
Width	4 HP
Depth	30 mm
Power Consumption	10 mA @ +12V, 0 mA @ -12V, 0 mA @ 5V
Function	Dual Channel Send/Return Pedal Integrator
Send Attenuation	1:20 (÷20)
Return Gain	20:1 (×20)
Send Connectors	1/4" TS, 1/8" TS (dual jacks per channel)
Return Connectors	1/4" TS, 1/8" TS (dual jacks per channel)
Input Signal Level (Send)	Modular Level (±5V)
Output Signal Level (Send)	Instrument Level (-10dBV)
Input Signal Level (Return)	Instrument Level (-10dBV)
Output Signal Level (Return)	Modular Level (±5V)
Internal Circuitry	Based on TL072 op-amp
DIY Availability	Yes, kit available for €64 (excl. VAT)
Front Panel Options	Black (standard), custom colors available (Red, Green, Blue, White, Gray, Bronze, etc.)

Key Features

Dual Independent Channels with Flexible I/O

Two full send/return paths let you run stereo effects or keep two separate pedal chains, say one for time-based effects like delay and reverb, another for filters and modulation. Each channel has both 1/4" and 1/8" jacks, so you don't need adapters. Full-sized guitar cables go in one side, a boutique pedal with mini-jacks on the other. The dual jacks are wired in parallel, so you can daisy-chain or switch between devices on the fly. In a live setup, that's the difference between a smooth transition and a crouching cable struggle.

Precise Level Matching, No Guesswork

The send path cuts the signal by a factor of 20, bringing the hot modular output down to a safe instrument level. The return path applies a 20x gain boost, restoring the weaker pedal signal to full modular strength. These aren't approximations; forum testing and manufacturer confirmation back up the exact ratios. The result is no noise penalty, no signal starvation, and no clipping. There's no EQ coloring and no added saturation (unless your pedals bring it).

Minimal Power Draw, Maximum Rack Efficiency

The module draws only 10mA from the +12V rail and nothing from the -12V or 5V. In a small case where every milliamp counts, that helps. It fits in a 32HP case with a modest power supply, and the negative rail is never loaded. It's also dead silent - no hum, no crosstalk, no ground loops - assuming your build or unit is healthy. The circuit uses the TL072, a JFET op-amp known for low noise and high input impedance, which suits a buffering job like this.

Historical Context

The ADDAC200PI launched around 2015, while the Eurorack boom was accelerating and integration with effects was still clunky. Most modular users either avoided pedals entirely or jury-rigged solutions with mixers, attenuators, and line drivers, which wasted HP and added noise. ADDAC System, a Lisbon-based boutique builder known for blending analog and digital concepts, saw the gap and filled it.

At the time, few manufacturers offered dedicated pedal interfaces. Doepfer's A-138d came close but lacked the dual mini/macro jacks and compact footprint. The ADDAC200PI took its place by being minimal and complete: no extra features, no digital control, just two clean channels. It arrived as modular setups grew more complex and performers wanted to bring in familiar floor-based gear.

This was also when DIY culture surged in Eurorack. ADDAC offered the 200PI as a kit. At €64 (excl. VAT), it was accessible to builders, and the assembly guide is clear, well-illustrated, and beginner-friendly. Soldering your own 200PI means understanding its function at a component level.

Collectibility & Value

The ADDAC200PI isn't a collector's item in the traditional sense. There are no limited editions and no celebrity endorsements. New units sell for $120 - $139 depending on the retailer, with Reverb and Perfect Circuit listing them around $135. Used prices hover between $80 and $110, and good units don't linger.

Apart from the op-amp, it's a passive signal handler, so failure points are minimal. The most common issues are mechanical: damaged jacks from repeated plugging, or loose panel screws. The TL072 op-amp can fail like any IC, though reports are rare. Units that hum or cut out should be checked for cold solder joints, especially on the power header or jacks. The design is simple, so repairs are usually straightforward for anyone with basic soldering skills.

If buying used, test both channels with a known-good pedal chain. Check for consistent signal level, no crackling, and no channel imbalance. Also verify the power draw - anything pulling more than 10mA on the +12V rail suggests a problem. Since the module draws nothing from the -12V, a damaged negative rail connection won't affect operation, but it could point to broader power distribution issues in the case.

The DIY kit remains available, which keeps prices in check. You won’t find vintage premiums or scalpers hoarding 200PIs—this is gear for users, not speculators. But that’s a compliment. In a market full of overdesigned, overpriced modules, the 200PI endures because it’s honest, functional, and fair-priced. It’s the anti-hype module.