Do all 700:7Rs suffer from intermitent buzzing?
Ever since I aquired my 700 back in March it has suffered from an intermittant buzzing, not on the output but from the unit itself. I would have asked this question earlier but I was hoping that a pattern would emerge. It hasn't and it does seem pretty random.
There are two levels of noise. The most frequent is loud enough to hear from my listening position but only during the 'quiet bits'. This never happens immediately on waking up the amp but often when it has been on for a few minutes. The noise will eventually disappear sometimes after just a few minutes but sometimes longer. It cuts in and out rather than fades. A straightforward 'warning up' issue you might think but sometimes it will cut in again after hours of use. I am fairly sure that the volume and the number of channels in use makes little difference. It is mounted in a rack with ventilaton all round.
Less frequently it moves up a gear and a more violent buzz happens. This you can hear at normal listening levels. It normally lasts for just a few minutes. The first time it happened I was sure that the unit was about to go bang.
For a long while I thought that the unit would either fail or the issue might go away when it was run in. It now seems clear that it is probably not going to do either.
Its something I can just about live with, but I would like to know if this is normal. I'm guessing it is something to do with the mysterious Cascode Compensation. If anyone can explain in laymans terms exactly what this does I would be very interested.
No problems with the output at all. It sounds great.
Ever since I aquired my 700 back in March it has suffered from an intermittant buzzing, not on the output but from the unit itself. I would have asked this question earlier but I was hoping that a pattern would emerge. It hasn't and it does seem pretty random.
There are two levels of noise. The most frequent is loud enough to hear from my listening position but only during the 'quiet bits'. This never happens immediately on waking up the amp but often when it has been on for a few minutes. The noise will eventually disappear sometimes after just a few minutes but sometimes longer. It cuts in and out rather than fades. A straightforward 'warning up' issue you might think but sometimes it will cut in again after hours of use. I am fairly sure that the volume and the number of channels in use makes little difference. It is mounted in a rack with ventilaton all round.
Less frequently it moves up a gear and a more violent buzz happens. This you can hear at normal listening levels. It normally lasts for just a few minutes. The first time it happened I was sure that the unit was about to go bang.
For a long while I thought that the unit would either fail or the issue might go away when it was run in. It now seems clear that it is probably not going to do either.
Its something I can just about live with, but I would like to know if this is normal. I'm guessing it is something to do with the mysterious Cascode Compensation. If anyone can explain in laymans terms exactly what this does I would be very interested.
No problems with the output at all. It sounds great.