Mar 1

Written by:
3/1/2009 6:45 PM 

One of my favorite synthesizers is the Sequential Circuit Prophet-5 which was one of the first fully programmable analog polyphonic synthesizers introduced in the 70's. The Prophet-5 was manufactured in tree major revisions between 1978 and 1984. The first and second revision of the Prophet-5 used SSM chips, while the later rev 3's used CEM chips. Sonically there are many people insisting that the SSM-based Prophet's are better sounding than the rev 3's but I think its purely a matter of taste.

The Prophet-5 owned by NEriks Audio is a rev 2 that have undergone extensive updates to the power supply and digital board in order to make it more reliable. Generally, rev 2 Prophet's seem to have a rather bad reputation when it comes to reliability. My experience is however that most issues concerning reliability may be rather easy to fix just by updating the power supply and replacing all the tantalum capacitors in it. From a serviceable point of view it may be wise to continuously maintain an old Prophet since a failure may be very expensive to repair.

One of the most expensive parts in a Prophet-5 rev 1 or rev 2 nowadays is the SSM chips which are getting more and more difficult to source. As an example, the SSM2040 voltage controlled filter chip seems to be getting more and more expensive every time I see one for sale. A few years ago I was asked by a client to restore a Prophet-5 rev 2 which partially had been cannibalized in order to repair another Propet-5 rev 2. When I opened the unit I discovered that all SSM2040 was missing. Getting five new SSM2040 resulted in a total cost of approximately $250 ($50 each).

A few days ago I was contacted by a guy in Japan who I previously have done some business with. He asked me if I was interested in buying his stock of SSM2040 at a price of $120 each. Initially, I turned his offer down due to the high price but after some thinking I finally decided to accept his offer. I'm aware that I probably have paid an overprice for the SSM's but on the other hand I'm one step closer to secure the future of our Prophet-5 rev 2 ...
 

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