Goblin – MIDI Upgrade

The Goblin is a MIDI upgrade for guitar, bass and other effects devices. With the Goblin it is possible to control effects device via MIDI. It’s the next evolutionary stage of the Imp.

Many larger pedals have multiple switches. E.g. delay pedals that have a bypass as well as a tap tempo switch. Or overdrives that have several separately switchable channels. In addition, useful functions are often assigned to external connections (usually marked with EXT, CTL, TRS, or EXP), which can be operated with a foot switch (e.g. Strymon Favorite switches) or expression pedals.

In order to bring all these functions into the MIDI universe, the Goblin has three freely assignable ports that can either control a conventional bypass switch, a tap tempo switch, two lines of an external switch a preset encoder (e.g. EHX POG2) and even expression inputs.

Features:

  • MIDI controllable bypass, tap tempo, TRS connection, preset encoder, or expression input
  • Controls up to three SPST switches (Goblin-SPST)
  • Replaces two 3PDT true bypass switches (Goblin-3PDT)
  • Controls expression input (Goblin-EXP)
  • Switch MIDI clock synchronously
  • MIDI channel can be set using the switch
  • Compatible with all MIDI 1.0 compliant controllers
  • True Bypass Relay Switching (Goblin-3PDT only)
  • Effect monitoring for reliable status (on/off)
  • MIDI clock synchronous LFO waveforms (Goblin-EXP)
  • Simple installation by screws
Goblin-SPST und Goblin-3PDT MIDI Upgrade Kit
Goblin-SPST (l.) and Goblin-3PDT (r.) with mounting screws

Variants

There are three variants, depending on the effects device to be modified

  • Goblin-SPST: For effects devices with multiple SPST, tap tempo switches, or connections for external switches.
  • Goblin-3PDT: For effect devices that have one or more 3PDT switches and optionally an additional SPST switch or external switch connection.
  • Goblin-EXP: Like the Goblin-SPST but with an additional potentiometer for expression inputs.

Goblin-SPST

The SPST variant uses existing SPST soft switches and their control electronics (which can be e.g. a microcontroller and relay – marked with CTL in the picture) and takes over the control, triggered by the switch, or MIDI. It does not matter whether the switches are independent of one another or what function they perform.

Effects device with three SPST switches
Effects device with several SPST soft switches before the conversion.

The original switches are retained during installation. The Goblin is installed between the switches and the effects device. Effects devices with SPST switches and relay switching often do not remember the switching status after powering down (e.g. Earthquaker Devices). The Goblin also fixes this problem and remembers the switching status after turning off.

Effects device after installation of Goblin-SPST MIDI Upgrade Kit
Effects device with several SPST soft switches after installing the Goblin SPST

Following the example of the Garbage Collector the Goblin can control external switch connections (e.g. Strymon Favorite Switch, external Tap Tempo etc.).

Effects device with external switch
Effects device with connection for an external switch before installing the Goblin

The Goblin can control two lines of such an external switch connection at each port. These lines then can be switched, pulsed and also synchronized with MIDI clock, or used normally from the outside.

Effects device with external switch after installation of Goblin-SPST MIDI Upgrade Kit
Effects device with connection for an external switch, after the installation of the Goblin.

Goblin-3PDT

The 3PDT variant of the Goblin has up to two relays as a replacement for true bypass 3PDT switches. In addition, either a tap-tempo switch or an external switch input can be controlled.

Effects device with 3PDT true bypass switching and external switch
Effects device with two 3PDT switches and an external switch input before installing the Goblin-3PDT

During installation, the original 3PDT switches are removed and replaced with SPST soft switches. The socket for external effects can still be used normally, or it can be switched from inside via MIDI.

Effects device with 3PDT true bypass switching and external switch after installation of Goblin-3PDT MIDI Upgrade Kit
Effects device after installation Goblin-3PDT

The ports can take on different roles, e.g. a third switch can be operated instead of the external switch.

Effects device with 3PDT true bypass switching and tap tempo after installation of Goblin-3PDT MIDI Upgrade Kit
Effects device with additional tap-tempo switch with Goblin-3PDT

A special feature of the Goblin-3PDT is that its cable connections are laid out in a 2.54mm grid. In this way, neat cabling with flat ribbon cables are possible. It is also possible to attach the Goblin-3PDT to other electronics using pin header connectors. Effect manufacturers in small series can easily integrate relay bypass and MIDI into their effects.

Goblin-3PDT with pin header (l.) and without (r.)
Goblin-3PDT with pin header (l.) and without (r.)

Goblin-EXP

The Goblin-EXP has the same features as the Goblin-SPST, but with an additional digital potentiometer to emulate an expression pedal.

Effects device before installation of Goblin-EXP
Effects device with two SPST switches and an expression input before installing the Goblin-SPST

Similar to the wiring of switches, the signals are tapped at the socket. The Goblin-EXP only supports Expression inputs with a maximum of 5V.

Effects device after installation of Goblin-EXP
Effects device after installation of the Goblin-EXP. The expression input is now controlled by the Goblin-EXP

LFO Waveforms

Like the Garbage Collector the Goblin-EXP has an internal, MIDI clock synchronous, LFO engine with three different waveforms to drive the Expression function. Choose between sine wave, square wave or sawtooth forward and backward. The speed of the waveforms depends on MIDI clock, with one pass being either whole, half, quarter, eighth, or sixteenth notes. The waveforms can be further altered in starting point, amplitude and position.

Goblin-EXP LFO Waveforms
Three different waveforms: sine, square and sawtooth (forward and backward)

Installation

Screws

Using two screw holes with screws and spacers available separately in the shop, the Goblin can be mounted on the base plate. With an installation height of only around 15 mm sometimes the Goblin fits under the switch.

Goblin-SPST in a Earthquaker Devices Palisades
Mounting the Goblin-SPST on the base plate of an Earthquaker Device Palisades
Goblin-SPST in a Strymon El Capistan
Goblin-SPST in a Strymon El Capistan
Goblin-3PDT in a Black Arts Toneworks Raw Heart OD
Goblin-3PDT in a Black Arts Toneworks Raw Heart
Goblin-3PDT in a Black Arts Toneworks Raw Heart OD
Goblin-3PDT mounted on the base plate

Switches

Additional SPST switches are required for the Goblin-3PDT. These have to be Normally Open and can of course also be ordered in the shop.

Media

Goblin-SPST in a Earthquaker Devices Palisades

Goblin-3PDT in a Electro Harmonix POG2

Goblin-EXP in a EHX Pitch Fork

In-depth explanation of the functionality and features of the Goblin-SPST in a UAFX Starlight delay

Goblin-SPST in a Strymon El Capistan


Instructions

Besides the user manual in the table below, there is a extensive documentation on how to install the Goblin-SPST in a Strymon El Capistan and how to install the Goblin-EXP in a EHX Pitch Fork. These are also good guidelines for installing the Goblin in any other pedal and has some hands on examples for the configuration. Also there is an addition to the installation manual that explains in depth the roles, measurements and the configuration.

DocumentVersionDownload
Quick ReferenceAll Imp and Goblin versionsEnglish | German
User Guide All Goblin versionsEnglish | German
InstallationGoblin-EXP – 1.0.2English | German
Installation Goblin-SPST – 1.0.2 English | German
Installation Goblin-3PDT – 1.1.2 English | German
SpreadsheetConfiguration HelperEnglish
Quick ReferenceGoblin-3PDT in EHX POG2English
Quick ReferenceGoblin-EXP in EHX Pitch ForkEnglish
InstallationGoblin-EXP – 1.0.0English | German
InstallationGoblin-SPST – 1.0.1English | German
InstallationGoblin-3PDT – 1.0.1/1.1.0English | German