[sdiy] Re: Source of 2N5459 FETs or building ARP clone

[Rob Keeble]

Hi,
I am currently cloning a number of ARP 2500/2600/Odyssey analog synth
modules, after successfully cloning some E-mu Modular designs. The modules
are being built under the name of Analog Metropolis, and PCB's *may* be
available for Synth DIYers in the future. Details of the modules are here:
http://www.emulatorarchive.com/AM/AM4000/am4000.html

The web site will have more information as the cloning progresses.
VCF/ADSR's are usually first, followed by VCO's.
The transistors are either available or replacements can be found. A batch
of 1k87 tempco resistors 3500ppm are being manufactured, and 100 ohm tempcos
will follow for the ARP 2500 circuits. These tempcos will be for sale to
Synth DIYers.

Short term plans include:

AM4012 - ARP "moog" VCF
AM4075 - ARP Quadra/Odyssey 3 VCF
AM4006 - "moog" VCF from ARP 2500
AM4036 - Sample and Hold from ARP 2500
AM4100 - Odyssey VCO

Analog Metropolis 4000 Series modules are usually an enhanced clone, with
more features (eg. blue LED's, quality components).  The modules are based
around MOTM/Oakley electrical standards, and can be used with MOTM like
panels (or the AM panel format of 4U).

A good example of what has been recently achieved is the AM2470 LFO module.
http://www.emulatorarchive.com/AM/AMmodular/AM2470/am2470.html

Comments and ideas welcomed.

Rob K.
www.emulatorarchive.com


Let's see...Off the top of my head, there's not a whole lot in an ARP that
is
completely extinct
1)You will need a source of slide(or rotary, perish the thought) pots in a
number of values. well, actually, all you really need is 100K linear, 100K
audio, and 1Meg  audio.
2) 1.87K tempco thermistors..other values are more common. a little
re-scaling
will be needed
3)  you might have a bit of trouble finding an exact copy of the multi pole
transpose switch.
4) The 2n5910 in the oscillator is a little rare by now.
5) the 2n3958 (iirc) dual fet might be obs too
6) 2 bus pratt-reed keyboard
7) top octave divider in the Omni, getting hard to find
8) Hamamatsu vactrol array in piano, phaser2 and bi-phase probably extinct.
9) piano keyer chips - gone
10) ? I don't know, it has been 25 years.....
The rest of an ARP is just opamps, transistors, resistors and capacitors.
-Dana