I just acquired a very nice Pro 700. It showed up yesterday. The gentleman that I bought this from tells me that it was serviced by Ed [ Oldphaser ] a few years ago. He claims he never plugged it in since its tune up
Enjoy, Don
Don,
A "few years ago" goes by quickly. More likely 5+ years ago. What is the date code on the output transistors?
Audio Analysts did a good job to taking care of these amps. The reason they engraved the front panels is so that they could quickly see by comparing to a list if the annual preventative maintenance was due. Audio Analysts had Jensen make custom racks for these amps (4 amps per rack) and the back of the racks had large fans mounted on them. None of the 40+ Audio Analysts amps I have worked on over the years had any of the normal heat affected areas under the large dropping resistors on the PL36 pc boards.
If my memory serves me correct, they installed 15A line supply fuses and 10A B+ and B- fuses. I can't remember if I subsequently re-installed smaller fuses; 10A line supply and 8A B+ and B- fuses. It is also interesting to see that this Audio Analysts PRO700 has the larger Dale NH-50 5 ohm 50 watt resistors installed like many of the later Clair Brothers amps. It appears that some of the commercial versions of the PRO700's did not.
More than likely, I also did a little detailing on the amp, painting the transformer, end bell, rack handles, new fuse caps, new transformer bolts, washers, polished speaker binding posts, etc.
Many of the power cords on the PRO700's had a red stripe on them that I don't recall Phase Linear using on any other of their products. I don't think the power cord was necessarily any larger than normal (i.e 15A AWG16).
I have some photos of the amp racks I did for Darrel Fisher. Darrel also faxed me some Audio Analysts info on the distribution network (passive crossover?) that were installed in the amp racks as well as a maintenance check list. I'll search for them later and if I find them I will post them.
By the way, it looks like the original power switch is still installed? From what I can see from the photo (from the top view of the switch) is that only (1) side of the switch (or should I say (1) set of contacts) is currently being utilized. I would suggest soldering across (jumpering) to the other side by installing a .0027uF .to .05 uF 500 volt or larger capacitor. This should help prolong the life of the power switch.
Ed
