ARP Quadra Model 2461 SN 24610149

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"Ready to ship after a full overhaul by our head synth tech James Walker.

This has had a serious amount of work, all done here by James Walker. Careful, painstaking and thorough are all words that apply. But more importantly, if we make such a claims for a synth of this pedigree and rarity, we can back that up. The list below from James includes over £500 of parts replaced, and we’ve also included a couple of photos of the bag of bits that came out it. Are you sitting comfortably…

On the rear of the unit all but the mains switch have been replaced. This includes all new Switchcraft 1/4 inch and 1/8 inch Jack sockets, Switchcraft XLR male socket , new IEC Mains Inlet socket and new program protect toggle switch.
The keyboard has had all its bushes replace and the buss bars and j wire contacts have been straightened and cleaned. The key caps have been cleaned and levelled.
The Aftertouch sensor has been replaced with a new ‘Force Sensing Resistor’.
All of the sliders on the Quadra have been removed, disassembled, cleaned, deoxit-ed, lubricated, reassembled, tested and reinstalled.
Three broken sliders have been replaced.
The power supply unit has been completely over hauled. The includes all new main smoothing caps, decoupling caps, replacing tantalum capacitors for wet electrolytic capacitors and replacing ceramic capacitors too.
The power transistors are new as are the plus 5 volt regulators. The linear power supply regulator is new. I’ve replaced all the rectifier diodes and power resistors. I’ve replaced the PSU trimmer for a new CTS trimmer.
I’ve also added two new 20mm fuse holders, to facilitate use of replacement, the original fuses were 32mm wire ended and soldered in.
All tantalum decoupling capacitors have been removed from the Quadra. Where tantalum capacitors we’re used to decouple the power supply lines, I’ve replaced them with wet electrolytic capacitors. Where the a tantalum capacitor functioned as a timing element I replace them with new tantalum capacitors.
All Molex headers,sockets and plugs have been replaced with new Molex products. This includes connectors on the keyboard. Also all wire-to-Molex crimps have been removed and re-crimped with new Molex crimps.
Where necessary any ribbon cable that has been damaged has been replaced with original NOS ARP ribbon cables.
All the sustain capacitors on the upper and lower poly boards have been replaced.
The two ARP filter modules ( 4075) have been recapped and had the extended range mod installed to extend the cut off frequency to 20KHz.
Most of the logic ICs on the keyboard interface board have been replaced.
The CPU board needed various new logic chips , along with new memory and a new Microcontroller. The DAC is new.
Various LEDS have been replaced with original NOS ARP stock.
Finally the end panels have been replaced with new leather end cheeks.
Unit is calibrated and fully working."