BUGLE2 Phonostage Kit PCB
7
Installation
Congratulations! Your Bugle2 is now complete and ready for installation.
Testing
If you have a DVM you can perform additional electrical testing prior to installation.
With power applied, the DC voltage on the outputs should read 0V (or less than
20mV). The voltages (relative to the grounding post) on pin 8 of the opamps should
be a positive voltage of r10V. Each opamp will have a different reading, as
the extensive filtering is lossy, so the input opamps have the lowest voltage. The
voltages on pin 4 of the opamps will be negative, roughly –10V.
If you want to measure bandwidth or frequency response, you will need an iRIAA
filter, a sinewave oscillator, and either an oscilloscope or AC voltmeter. A quick check
for equalization accuracy is to apply a 500Hz square wave. The output waveform
should be identical in shape. If there are droops, sags, overshoots, or spikes, the EQ
is in error. If you have built the unit per these instructions such testing is not
necessary.
Operation
Connect a cable between output jacks and your audio system. Attach the turntable
ground wire to the grounding post and connect the turntable RCA output plugs into
the Bugle2 input jacks. Plug in the power supply. Enjoy!
The Bugle2 must get an Earth ground from the linestage or receiver via the
connecting cables; otherwise there will be hum. If the inputs to the linestage are
floating, then add an extra ground wire to the Bugle2.
Troubleshooting
If the sound is not good, double-check all resistor values to make sure they were
installed into their correct locations.
If a channel has a scratchy sound to it (not a nice clean, quiet hiss) then it is likely
the input opamp has been damaged and should be replaced. These devices are very
sensitive to ESD and precautions must be taken. Hum, buzz, and other noise sources
(WiFi) can be induced into the Bugle2 and/or input cables via close proximity. Place
as far from other equipment as possible.
