[dave a[_2_]]

On 5/18/2010 6:47 AM, Peter wrote:
Since I am considering switching to an all Quad HiFi system I was quite
disappointed to learn that the Quad Electroacoustics Company only offers its
special "balanced" Quadlink cables with a maximum length of one meter.

In my setup the preamp is about 20 to 30 feet away from the power amp (I
have to go around the room), since I am trying to follow the conventional
wisdom of keeping the power amplifier as close as possible to the speakers.

Therefore I contacted the Quad Company and was told that they recommend
using plain RCA cables for long runs between their 99 preamp and their 909
power amp. Frankly I cannot understand the reasoning behind this since
generally speaking balanced connections supposedly always provide better
results.

In light of the above I wonder if anyone might know a company that would be
willing to build a 30 foot Quadlink (AmpBus) cable which will indeed meet
Quad Company specs?

I also wonder if someone might be able to provide me with a schematic for
the 15 pin connectors used for the Quad Quadlink cables, and perhaps also
the identification of the connectors themselves?

Thank you in advance for your very kind help and consideration.


I was unfamiliar with the Quad products or their proprietary
interconnects so I did a little Googling. First, QuadLink and AmpBus
appear to be two different things. Quadlink is to be used between
source and preamp while AmpBus is used between preamp and power amp.

Frankly, I wouldn't use either of them. Quadlink mixes low level
signals with power lines for a possible FM tuner. Why one would do this
is beyond me. Ampbus does appear to offer differential signals, but
this is only really useful in high noise environments or with long runs
of cable where common mode noise might be an issue. Since they only
offer the AmpBus in 1m lengths, it is clearly a marketing tool.

Finally, I question your assertion that one should locate the power amp
as close to the speakers as possible. It makes more sense to me to
locate the preamp as close to the power amp as possible as these are
much lower level signals and therefore more susceptible to noise than
the signal from your power amps.

dave