In the studio I built last year, I wired all with type AC (aka "BX")
cable where the power is inside and armoured metallic sheath, so the
power starts out well shielded. This also provides a substantial
ground. I have the ground ringing the main operations area of the
studio, and the power panel for the studio is in the middle rear, so
there is little chance of any ground voltage differential between any
two points in the studio.
Wherever possible, I use balanced interconnects.
I keep low-level, unbalanced interconnects short, away from AC power.
My turntable preamp is right next to the turntable and connected with
well-shielded cable. In fact, the shields are only grounded at one
point so, while not balanced, there is no possibility of a ground
gradient superimposed on the cable.
The unbalanced connections I have are between my jackfield and the
unbalanced equipment. In the jackfield are 4 Aphex 124A balanced to
unbalanced converters. The jackfields are colour coded so that I know
what's balanced and what's unbalanced. All the unbalanced stuff goes
into the converters.
The entire monitor chain is balanced with a Blue Sky Bass Management
Controller and 5 Mackie HR-824 monitors. I think the connection to
the sub may be unbalanced.
I did broadcast system design professionally from 1974-1981 for
ABC-TV, 1981-1983 for McCurdy Radio (along with circuit and product
design), and then from 1983-2004 with National TeleConsultants. There
are lots of little things. We had a saying at NTC "God is in the details."
Did you put "isolated ground" power in the studio? That often causes
more hum believe it or not.
At 01:56 PM 4/18/2006, Kurt Nauck wrote:
>We are doing some re-arranging of our studio here at the
>shop. We're encountering hum from the audio cables being in
>proximity of power cables and possibly from florescent lighting
>(!) Is there some way to shield audio cables from the influence of
>power sources? I've read that one should always cross audio and
>power cables rather than having them run in parallel. Any
>suggestions would be appreciated!
Tape Restoration Seminar: MAY 9-12, 2006; details at Web site.
Richard L. Hess email: [log in to unmask]
Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
Detailed contact information: http://www.richardhess.com/tape/contact.htm