Prophet 5 blues

[jdm at synthcom.com]

At 10:19 PM 7/12/97 -0700, Wayne Thompson wrote:
>A little off topic but......
>
>After finding a MINT!!! Prophet 5 I thought I had the world by the balls
>but.........
>On the second day of twiddling knobs it decides to shut down.  All the
>program lights went off and the sound that was playing continued until
>the end of the env's and then nothing.  This is a rev 2 (I checked under
>the hood according to the tech manual I recieved with it and sure enough
>it says Rev.2 on the pcb boards)
>Here are my questions:
>
>Any ideas why it did what it did?  The last sound I was playing with I
>was using osc in lo freq mode and playing in unison.

Because it's a Prophet, reknowned for unreliability.  It's always fun to
read old New Order interviews about how many Prophet 5's they had to lug
around in hopes of having ONE working for a show (and that one would usually
break down in mid-song).  I know a guy who worked at Sequential in quality
control who quit because management wouldn't listen to him.  I sold a Rev.3
due to unreliability, and Rev.3's are more reliable than Rev.2's.

However, it's not a lost cause.  You're just probably going to have to do a
lot of rework to make it reliable.

First thing to do, as with any computer-based system, is re-seat all the
chips by pushing them down with your thumb.  This usually cured my P5
problems.  Sequential used incredibly cheap sockets which have now reached
the end of their useful life, due to thermal expansion and contraction.  THe
boards sit upside down, as I remember, so gravity aggravates matters.  I
would recommend clipping them all out and replacing them with machine tool
sockets, one at a time (after you get it working again, off course).

The power supply is the next thing to check.  Sequential put wimpy supplies
in P5's.  They tend to fail due to overwork.  I made my P5 more reliable by
modding it to give it a little more capacity; in retrospect replacing it
with a beefier supply would have been better.


>I talked to wine country and they said "we don't work on rev 2's"
>Any reason why???? ssm chip availability???

Because they don't know their ass from a hole in the ground.  If you want
someone that's more than competent to work on it, try Kevin (Synthfool)
Lightner.


>If I get it running would the midi kit be a good idea or am I always
>going to have problems???

Only if you replace the power supply.  Remember, the Rev.3 kit won't work,
you need a Rev.2 kit from Kenton. 

Good Luck
JDM