2. misc-audio
  3. 1141605720

Mcintosh transformer hum

I recently acquired a Mcintosh MC 7104. It is in mint condition, and works perfect except for one annoying issue. There is a physical/mechanical hum eminating directly from the transformer. It is not loud, but is audible from a few feet away when the room is completely quiet. It is sometimes noticeable on quiet passages from my chair. About as loud as a purring cat. I haven't had this problem with any other audio equipment, but feel it might be a power issue. Could this amp be more sensitve to power conditions or could it be defective? It does sound great except for this. Any suggestions?

B&K 4090 pre
Sony S9000ES DVD/CD/SACD
Mc 7104 (bridged to 2 ch) replaced B&K 120x2
Yamaha MX830 (for sub)
B&W 705
Peerless subwoofer 12DVC (DIY)
Dahlquist active crossover
audioquest and vampire interconnects
robbirdsmedia

Showing 1 response by aball

aball
2,018 posts
 
I have never heard a McIntosh make any sound. There could be two simple problems - the transformer got loose in shipping or the grounding is bad. The latter could be a loose chassis ground or your outlet/circuit/house has a bad ground.

You could take the cover off and check these things very easily. It should be rather obvious. Also, Joe is right about trying out a cheater plug.
More to discover