I`ve lusted after one of these for many a decade. The 700B has been on my "must have list" for the longest time now but unfortunately, finding a unit in decent condition and at a rational price has proved to be a difficult endeavor. It is the last amp to be crossed off a list that includes other major players such as Crown, BGW and Yamaha, but has proved to be the most elusive, until now. I just had the good fortune to score a near NOS, one owner 700B complete wooden sleeve, owners and service manuals, sales brochures along with original packaging. 
I`d normally be a little apprehensive in placing any piece of electronic equipment of that vintage into a regular routine but even more so with a PL. Not to insult any owners , there is no denying the bad press some of these amps get given their tendency for going Supernova and taking out all connected speakers as a bonus
Why is that? Is it an inherently unstable design, a bad component choice and implementation or does it just have difficulty coping with difficult loads (below 8R) or were they put into applications they were never intended for? Was this more a 400 or 700 issue?
Many Sound Reinforcement companies and recording studios used these amps back in the day as they were more powerful than anything else that was available at the time, so they couldn't have been that bad. Potential reliability issues aside, there must be something positive said with regards to their fidelity for them to be as popular as they were/are.
I suppose some kind of load protection can be integrated to minimize the consequences of a catastrophic failure but avoiding those issues altogether would be ideal if at all possible.
Are replacement parts readily available or are some unobtainable?
That said, I`d love to hear from current and past owners of such beasts and their experiences, good, bad or ugly
along with any advice pertaining to preventive maintenance, operating guidelines etc. Im really wanting to like this amp. I hope the sonic's and performance match its coolness factor. It will be driving a pair of JBL L112 btw, a stable and efficient load. Anxiously looking forward to it`s arrival and your replies!
I`d normally be a little apprehensive in placing any piece of electronic equipment of that vintage into a regular routine but even more so with a PL. Not to insult any owners , there is no denying the bad press some of these amps get given their tendency for going Supernova and taking out all connected speakers as a bonus
Many Sound Reinforcement companies and recording studios used these amps back in the day as they were more powerful than anything else that was available at the time, so they couldn't have been that bad. Potential reliability issues aside, there must be something positive said with regards to their fidelity for them to be as popular as they were/are.
I suppose some kind of load protection can be integrated to minimize the consequences of a catastrophic failure but avoiding those issues altogether would be ideal if at all possible.
Are replacement parts readily available or are some unobtainable?
That said, I`d love to hear from current and past owners of such beasts and their experiences, good, bad or ugly
