PS Audio DirectStream Junior - Ground loops

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Troubleshooting xxvi
Troubleshooting
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Owner’s Reference DirectStream Junior
If this doesn’t solve the problem, reconnect DirectStream Junior and follow these
easy humbusting tips.
The easiest way to gure out where ground loop problems lie is by the process of
elimination. You need to determine where the hum or buzz is coming from within
your system.
If the hum/buzz goes away when you remove the inputs to the power amp, your
next step will be to reconnect the amp and move further down the chain. If you
were working with a receiver or an integrated amplier, you will need to jump to
step 4. If you have a preamp, or processor that is feeding the power amp, your
next step would be to disconnect all inputs to the preamplier or processor. Once
these are disconnected, and the preamp or processor is connected only to the
power amplier, turn the system on and again, listen for hum. Should the hum
now appear, it is a problem with your preamp, processor, DAC or their interaction
with the power amp. Before returning the preamp, processor or DAC to the
manufacturer, try a cheater plug to break a ground loop. Cheater plugs are simple
devices that convert a three prong AC plug into a two prong AC plug and in the
act of converting three prongs, to two prongs, they disconnect the ground from
the wall socket. Try one of these on the preamp, or the power amp, or both.
If you determine that there is still no hum present when the preamp, processor, or
DAC is connected with no inputs, then selectively begin plugging in your various
inputs one at a time. After each connection, check for hum until you discover the
humming culprit.
VCR’s, surround processors, and any device that is connected to a television
cable or satellite dish can cause a loud buzz and should always be suspect. If, by
the process of elimination described above, you determine it is a component like
a VCR that is causing the hum/buzz to occur, and using a cheater plug doesn’t
help matters, it may be necessary to isolate the cable connection (CATV) with an
isolation transformer. This inexpensive device is available at most Wal Mart, Radio
Shack or department store type outlets and is sometimes called a ‘matching
transformer’. If you have problems nding one, call your local cable TV company
for advice. The matching transformer will be placed between the cable TV cord
and the VCR, TV or processor.
Just remember, take the system down to its simplest level of connection. Find
a way to hook the system up with as many pieces of the system missing or not
Ground loops