Calleberg skrev:Utan att veta skulle jag ändå våga sätta en liten peng på att detta test visar att Schiitdacen (och många andra apparater med den, för det kan vara svårt) inte fullt ut lyckas koppla av luftburna störningar, och att den dessutom är konstruerad på ett sätt som gör att dessa störningar (i viss mån) även återfinns i jordplanet på den analoga sidan.
Ja du, det är nog inte endast Schiit-dacen som är känslig. Mitt rörförsteg är hypokondriskt när det gäller EMI.
Tillverkaren hävdar att det är en medvetet vald kompromiss för att prioritera de ljudande egenskaperna och att kraftigare verktyg för att reducera störningar skulle påverka ljudkvaliteten. Störningar påverkar ju också de ljudande egenskaperna, tycker jag då.
Citat från Conrad Johnsons manual för CJ Premier 17 LS.
"Considerable care has been taken in the design of the Premier 17LS to
minimize it’s susceptibility to radio frequency interference and other
forms of EMI. Choice of materials, physical layout, grounding practice,
and power supply design have all been specified with a view to reducing
the impact of electromagnetic fields on the performance of this unit. At
the same time, however, our primary goal is the accurate reproduction
of recorded music in the normal home environment, and we have
elected not to compromise this objective by the application of heavyhanded RFI filters, or by using grounding practices that reduce RFI at
the expense of degraded audio performance. We find that the approach
we have taken has worked extremely well, resulting in only rare instances of EMI problems which could be treated locally as needed,
rather than compromising the performance of our product in the 99.9%
of installations where EMI is not a problem.
Care in installation can often avoid EMI induced problems. The following
practices should generally be observed in any application, and will be
especially important where EMI may be a problem.
Interconnect cables should be kept as short as possible (3 meters or
less), and shielded cable should be used (cable which has two center
conductors, and a separate external shield connected at only one end).
Physical location and cable "dress" can be an important factor in
minimizing hum pickup. The installation should situate the preamplifier
well away from the power amplifier, and power (ac mains) cords should
be dressed to remain at least 4" (100mm) away from input/output
cables.
It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so.
M.Twain
Perhaps you say that it's not accurate? I say it's entertainment!
© 2012 Nelson Pass
