Conrad-Johnson ET5 Owner’s Manual
9
Vacuum Tube Replacement
The ET5 circuit employs one vacuum tube, a 6922. The 6922
offers low noise, low microphonics, and gain well suited to use in a
zero-feedback line-stage. The brands of tubes we supply have
been chosen by first selecting those brands which are known to be
most reliable, then by extensive auditioning of these acceptable
brands with the final choices being made solely on the basis of
sonic performance. We know of no vacuum tubes available which
will improve the sonic performance of your ET5. The tubes that we
supply have been tempered by a controlled burn-in procedure that
permits them to perform for a greatly extended period without sonic
degradation, and then selected for minimum residual noise.
Replacement tubes are prepared and selected in the same way.
Therefore, we highly recommend that you purchase replacement
tube sets from conrad-johnson design.
We anticipate tube life to accommodate two to three years of
operation without degradation in normal use - if the preamplifier is
switched off when not in use. If the preamplifier is left on at all
times, tube life can be exhausted in a matter of a few months.
