[Arny Krueger]

"GregS" wrote in message

In article ,
"fredbloggstwo"
wrote:

wrote in message
...
I'm looking for a low cost way to slightly attenuate a
-10db stereo RCA output from an FM tuner.

This is a small cable studio's playout system. There is
no mixer: Several devices (4 streams from a video
server, several tape and DVD decks) feed into a routing
switcher, then a compressor/limiter, then into
modulators and out into the cable system. It is
important to have all devices at the same approximate
level; While they are all -10db, the only significant
difference is the tuner. It is noticeably louder than
all the other sources. The tuner is a Rolls RS80, and
it has no adjustment for output level (except the
front-panel headphone jack, which I am currently using.
The protruding cable looks bad, and I want to use the
rear stereo RCA jacks.

I could use a cheap Behringer mini-mixer, but I'd
rather find one of those little "audio solutions" boxes
that will give me control of the level, definitely
down, but perhaps up also. Any ideas?

If you know the approximate input impedance of the
device you are connecting to, you can use a single
series resistor to pot it down. For example, if the
input impedance is 10k (this is the effective resistance
in the input to ground) a series resistance of 10K will
attenuate the signal to one half, or 6dB. A resistor of
20K will attenuate it to one third - about 9.5 dB. In
this case I would use a 22K resistor to get about 10dB.


Likely to work but more susceptible to capacitance
effects.

I build many of my attenuators into plug shells. The plug goes directly into
the input connector. Aternatively, build the attenuator in-line, and
minimize the lengh of the cable on the output side. Most attenuators can be
built in-line, shrink-wrapped to prevent internal shorting, covered with a
short piece of plastic tubing, and shrink-wrapped again for mechanical
strength.