Vintage ARP Explorer I Model 2900 Synthesizer Serviced w/ New Sliders

Description

The ARP Explorer I (Model 2900) was ARP’s first non-preset single oscillator synthesizer, pre-dating the Axxe and the Solus.  It includes the same 4027-1 Voltage Controlled Oscillator module found in the ARP 2600, and the same 4034 Moog Ladder Filter Voltage Controlled Filter module found in the ARP Pro Soloist.  The oscillator is divided down to suboctaves, and shaped into different waveforms (sawtooth, square, pulse, and fuzz) that can be combined simultaneously for an extremely fat sound from a single oscillator synth, particularly in partnership with the ladder filter.

This is a video demo of this exact synthesizer that is for sale:

The synth is in good condition with strong silkscreen, which is uncommon for this era ARP Synthesizer.  There are a fair amount of scratches and imperfections on the panel and the hardboard bottom panel is damaged, please see photos.   This synthesizer was serviced in September 2023 by Synthchaser, and work completed on the synth included:

• Synthchaser Precision slider upgrade –  All 12 of the old original sliders have been replaced with new, smooth, high precision sliders.  The difference in the way these sliders feel and perform compared to the originals is a huge improvement.   The original style slider caps are fitted to keep the look original.
• Power supply recapped – All tantalum and electrolytic capacitors in the power supply have been replaced, and high quality, high temperature 105 deg C capacitors have been used for the power supply filter capacitors.
• Tantalum capacitors replaced – The tantalum capacitors in ARP synths are ticking time bombs.  All tantalum capacitors in this synth (except those in the sub-modules) have been replaced with electrolytics to help provide stable operation for years to come.
• Keyboard rebuild – New key bushings installed, keys removed and ultrasonically cleaned, bus bars removed and polished, key contacts cleaned and adjusted.
• Oscilloscope calibration – Calibrated & tuned using oscilloscope and frequency counter.
• 1/4″ output made High – ARPs of this era had an RCA jack as the high output and the 1/4″ jack as the low output.  As today RCA jacks are an inconvenience for most, the 1/4″ jack has been made to a second high output.  This modification is easily reversible by cutting 1 wire.
• New power transformer – The original transformer had come loose and had some hum to it, and was replaced with a new toroidal transformer.

Prospective buyers are welcome to come try it out before purchasing. Local pickup is welcome and encouraged.  This is a vintage electronic item, so all sales will be as-is and final.  The keyboard will be packed well and insured for the full sale price.   If you are not familiar with me, please visit my Synthchaser YouTube channel to see some of my work.