Profile of David Friend:

Co-founder of ARP Instruments, Inc. together with the founder Alan Robert Pearlman. In addition to designing the ARP 2600 and Odyssey, he was involved with the development of numerous products, and subsequently entered management, eventually becoming president of the company. His achievements as an entrepreneur have also been acclaimed, and in 2010 he received the "Entrepreneur of the Year" (Emerging Technology category) award from Ernst & Young. After serving as the President and CEO of Blue Archive, Inc., currently he serves as the President, CEO and Co-founder of Wasabi, as well as being a lecturer at MIT's Sloan School of Management. He is also an emeritus of the New England Conservatory and Berklee College of Music.

Normalled Pathways

Nearly every slider and switch on the ARP 2600 front panels is hard wired to specific control source. For example, the front panel controls allow the pitch of Oscillator 1 to be controlled by the keyboard (On/Off switch), the output of the Sample & Hold module (slider), the shape of the ADSR envelope generator (slider), and/or by the sine wave output of Oscillator 2 (slider), and each in varying amounts. These hardwired pathways provide massive amounts of immediate control that make excellent use of all the ARP 2600 has to offer, allowing the ARP 2600 to be played as is – no patching needed. In true modular fashion, inserting a patch cord into the jack associated with any hardwired control overrides that internal connection, letting you create a new signal path of your choosing. As a programming aid, the detailed panel graphics clearly show the available signal routings.

Patch Bay Precision

Unlike earlier modular synthesizers that relied on bulky 6.3mm (1/4") jacks and patch cords, the ARP 2600 uses a more streamlined 3.5mm (1/8”) jack that allows for more patch points to occupy the same amount of panel space, delivering more options and more versatility. Most of the patch points are arranged in a single row below the controls of the individual sound modules. This arrangement keeps the main panel clear and unobstructed for tweaking the controls during performance. Needless to say, these patchable connections and the onboard processors can be used to interact with nearly any modular or Eurorack synthesizer system.

3620 Keyboard

While faithful to the original design, the functionality of the 3620 Keyboard has been greatly enhanced for this limited ARP 2600 release. The 3620 Keyboard contains 49 full-size keys, aftertouch, portamento, and is also duophonic, allowing two keys to be played at once – Single or Multiple Triggering is available. In addition, the duophonic keyboard can use an optional foot switch to lock the interval between any two notes, without retuning the oscillators during performance. Vibrato can be added via a dedicated circuit controlled by aftertouch, or by the onboard LFO (Low Frequency Oscillator), using any of three available waveforms. Most noticeable is the addition of a flexible Arpeggiator that allows a user-defined pattern to be manually sequenced and played back. Still present are the original Pitch Bend knob and the Two Octave Up / Two Octave Down Transpose switch. Connecting the keyboard to the main unit now uses a secure eight-pin din cable.

Processing Powerhouse

The ARP 2600 reveals its modular nature by the unique assortment of valuable, esoteric, and individually patch-able modules it contains. To begin, there are a set of parallel-wired Multiple jacks that enhance the patching possibilities – allowing the same control signal to be sent to multiple locations, for example. Three independent Voltage Processors provide scalable control voltages, or can act to attenuate any control signal. Use the Lag Generator to delay the start of any control signal. The Noise Generator is tunable to deliver White, Pink, and Low-Frequency noise, plus everything in between. A series of three Inverters can reverse the polarity of any signal. The Electronic Switch can be sync’d to either the internal clock or any external clock signal, as can the Sample & Hold rate. Most importantly, the ARP 2600 includes a dedicated Preamp and Envelope Follower for processing an external audio signal.

The Oscillators

ARP Voltage Controlled Oscillators (VCO) are extremely stable in their tuning. All three oscillators feature Initial Tuning and Fine Tuning sliders, and every oscillator can be designated as an LFO (Low Frequency Oscillator) modulating oscillator or as an audio oscillator. (Additional LFO modulation sources are available on the ARP 3620 keyboard; included.) Each oscillator generates multiple wave shapes at once. Available Waves include Sawtooth, Square, Triangle, Sine, and Pulse. The Pulse wave of Oscillator 2 and Oscillator 3 include a manual Pulse Width control, and Pulse Width Modulation is available on Oscillator 2. One audio oscillator can be used to modulate the frequency of another audio oscillator to create analog FM effects.

The Filter

The ARP 2600 is equipped with a 4-pole Voltage Controlled Filter (VCF), offering a roll-off curve of -24dB per Octave. As with the oscillators, the ARP 2600 filter also offers a Fine Tuning slider. The addition of Fine Tuning allows precise and useful control of the pitch of a self-resonating filter. The input mixer stage of the VCF includes sliders for each Oscillator, the Noise Generator, and the output of the Ring Modulator. Over time, the ARP 2600 historically went through a number of changes; some were cosmetic, and some were more crucial to the sound. The Filter Type switch selects between a filter response more closely related to either earlier or later models of the ARP 2600.