QUAD VA-ONE+, Owner'S Manual

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Valves contain a heating element. This heats up the valve's cathode, which is coated to give off a steady stream of electrons. After
a few years this coating will begin to wear out and performance will gradually deteriorate. The EL84 output valves are likely to
deteriorate first but the driver valves will also eventually wear out.
As the valves start to wear out the sound will become less well defined and a lack of dynamics and power will become evident.
Replacing the valves with a new set will fully restore the audio performance of the amplifier. When replacing valves it is essential
to use the highest quality available. Poor quality valves will adversely affect the sound quality and may, in extreme cases, damage
the amplifier. When replacing the output valves, use matched sets for best results.
Do not leave the amplifier permanently switched on or you will seriously shorten the lifespan of your valves!
Valve Lifetimes
After installing or changing the wiring to your speakers, set the volume control to zero, let the amplifier warm up and turn up the
main volume gradually. If you don't hear sound, switch off immediately and investigate.
The output transformer is designed to match the high voltage, low current conditions in which the output valves operate to the
low voltage, high current requirements of a loudspeaker. Although robust, an output transformer can be damaged and in
extreme cases wrecked by careless use. If you play a valve amplifier into a short circuit, the output transformer will soak up a lot
of energy before failing, but if the short persists the transformer could be damaged. Operating a valve amplifier at high output
level with no loudspeaker connected will also damage an output transformer.
The amplifier must be used with the correct load conditions, otherwise it may cause damage to the output transformer.
Output Transformer
With the increased popularity of downloadable or streaming digital files, the VA-ONE+ USB D/A converter allows consumers to
enjoy listening to digital music sources from a computer (Windows or Mac) via the USB connection.
This product is USB 1.1 and 2.0 compliant and supports sampling frequencies ranging from 35kHz to 384KHz
（ supports
DSD64 DSD128 DSD256 ） via the high quality Digital-to-Analogue converter (DAC). The DAC defaults to a 48kHz input
sampling frequency. With a digital source connected and playing, the VA-ONE+ USB DAC will detect the sampling frequency of
the input data automatically. The front panel indicators will then indicate the presence of a digital signal and the source selected.
Note: Windows does not support 192kHz sampling frequency. Owners of computers with Windows OS are advised to install
corresponding software provided in the accompanying CD-ROM. Simply follow the software installation instructions included.
USING THE USB SOURCE