ap123
Well-known member
Grant, thanks. Yesterday I did exactly what you described. In fact, I just double-checked it. I still get audible mechanical hum, though. After some more reading I'm beginning to wonder if my AC line is of very poor quality. I found this and thought it would be interesting to try: http://diyparadise.com/dablok.html This will apparently remove all DC from the AC line and minimize the transformer noise.
Another thing I read was that 1073 type circuits are very susceptible to radiant fields. I noticed that my two racked API 312 channels were not effected at all by their respective toroidal/PSU (in fact, they were ultra quiet) but that the chandler germanium was really picking it up. This is even with the API completely disconnected except for power; once I flip it on the germanium picks up the transformer noise from two rackspaces away. I'm assuming this is not a ground loop issue because it seems very dependent on proximity to the offending devices.
Update: I emailed chandler and wade said:
It is most certainly worth moving. I guess I shouldn't jump to blaming my shoddy DIY work! I think my problem was from a combination of thinks; a sensitive preamp and high DC presence in the AC line.
Another thing I read was that 1073 type circuits are very susceptible to radiant fields. I noticed that my two racked API 312 channels were not effected at all by their respective toroidal/PSU (in fact, they were ultra quiet) but that the chandler germanium was really picking it up. This is even with the API completely disconnected except for power; once I flip it on the germanium picks up the transformer noise from two rackspaces away. I'm assuming this is not a ground loop issue because it seems very dependent on proximity to the offending devices.
Update: I emailed chandler and wade said:
It is most certainly worth moving. I guess I shouldn't jump to blaming my shoddy DIY work! I think my problem was from a combination of thinks; a sensitive preamp and high DC presence in the AC line.
