Meet the TRIP: An Experimental Drum Machine from Noystoise

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Today we’re taking a deep dive into the Tandy Trip, an experimental drum machine and rhythmic drone-machine from the creative mind at Noystoise. This project is the spiritual successor to the “PAL” and is also derived from a classic RadioShack Musical Elephant Keyboard.

Overview

The TRIP is an experimental drum machine built around a dual-voice drum chip, which originally provided 8 pre-programmed rhythms. Noystoise used only the sound chip, building the rest of the circuit and a custom enclosure from scratch.

The goal was to create an experimental drum machine to accompany the PAL. While its creator notes it lacks the full programmability of a traditional drum machine, it excels as a “Rhythmic Drone-Machine,” perfect for nostalgic IDM. Its name comes from its ability to create “stumbling rhythms” and the capacity to get lost in its sounds for hours.

Features

The TRIP is packed with a surprising number of sound-shaping tools:

  • Global Pitch modulation
  • 8 preprogrammed rhythms with start/stop and tempo controls
  • Two drum voices: “TONE” (basic square-wave) and “NOISE” (pseudo-noise square-wave)
  • Two independent Envelope generators (one per voice) with Decay and Depth controls
  • Two independent resonant 12db Lowpass Filters (one per voice) with Cutoff and Resonance
  • Two independent VCAs (one per voice)
  • PT2399 Echo circuit with independent mix knobs for each voice
  • Dual 8-step analog Sequencer with reversing clock inputs
  • VARI SYNC variable Sequencer Clock
  • ARG (Attack Release Generator)
  • 8 Roll/Flam EG trigger inputs
  • 8-input multi-use capacitive-touch keys
Battery Compartment

PT2399 Delay Chip

The PT2399 is a CMOS single-chip echo processor developed by Princeton Technology Corporation, originally designed for use in karaoke machines and consumer audio devices to add simple echo effects.
It functions by converting analog audio signals into digital data via an integrated analog-to-digital converter (ADC), storing the data in 44Kb of internal RAM, and then converting it back to an analog signal using a digital-to-analog converter (DAC) and a low-pass filter.
The delay time is determined by an internal voltage-controlled oscillator (VCO) clock frequency, which can be adjusted by changing an external resistor, allowing for a delay range from a minimum of 30ms to a maximum of 340ms.
This chip is widely used in guitar effect pedals, DIY audio projects, and even in some commercial synthesizers and multi-effects units due to its low cost, ease of use, and distinctive lo-fi character.

We touched on the PT2399 chip with the following:

Summary of Features

Here’s a quick-glance table summarizing the main sections of the TRIP:

Feature SectionKey Functions
VoicesTwo distinct voices: TONE (square-wave) and NOISE (pseudo-noise).
Rhythms8 built-in rhythms from the original chip, with tempo and start/stop.
ModulationGlobal Pitch, 2x Envelopes, 2x Filters, 2x VCAs.
SequencerDual 8-step analog sequencer with one CV bank, reverse clock, and manual step-play.
EffectsPT2399 Echo circuit with separate wet/dry mix controls for each voice.
Control8 capacitive-touch keys for controlling Roll, Sequencer steps, and the ARG.
Sync/ClockVARI SYNC for clock division/multiplication; can be clocked internally or externally.
Circuits

Pricing, Availability, and How to Get One

So, how much does this cost and where can you buy it?

The Tandy Trip is not a commercial product for sale. It is a DIY (Do-It-Yourself) project.

The provided reference page includes a detailed “BUILD PROCESS” section, which describes the design philosophy and construction. This means there is no pricing in USD, EURO, GBP, or AUD.

How to Build One

Since this is a DIY project, “availability” in the USA, UK, Europe, or Australia depends on your ability to source the components and build it yourself.

The Noystoise website includes a “REPOSITORY” link in its main navigation, which is the most likely place to find build instructions, schematics, or other project files.

Below is a schematic of the project:

Build development

Release Date

The project details for the Tandy Trip were posted on July 2, 2025.

Reference: [1]

[1] Noystoise. (2025, July 2). TRIP. Retrieved from https://www.noystoise.com/2025/07/trip.html#more