6
X5 Owner’s Manual
Fortunately the amplifier is not sensitive to the capacitive/inductive
character of some of the specialty speaker cables, so feel free to
experiment.
We have found that about 90 per cent of bad sounding cables are
really bad connections, and we recommend that special attention be
paid to cleanliness of contact surfaces and tight fit.
Speaker cables should be firmly tightened down at the speaker
output terminals, but do not use a wrench. They will not withstand
100 foot-lbs of torque. Hand tightening without excessive force is
plenty.
The X5 has a power transformer, rated at 1000 watts, continuous
duty. Under actual conditions in the amplifier the transformer will
deliver about 1800 watts for short duration.
All the transistors in the product are power Mosfets, actually Hexfets
from International Rectifier and Harris. These are hyper-matched
parts, with gate voltages matched to 0.5% and all devices taken
from the same lot codes (made on the same wafer). The speed and
noise critical gain devices in the front end, (that is to say the actual
balanced pair of transistors) are ultra low noise and distortion
matched JFETs having a low (.02 S) transconductance figure. The
JFETs are made on the same substrate for prefect matching.
The X5 has 40 output Mosfet power transistors in TO-3 plastic
packages, again matched to 0.5% and drawn from the same lot codes
for each type. The output stages can sustain transients of about
1,000 watts per channel, but are not allowed to dissipate more than
half that, even into a dead short.
So how long will this hardware last? It is my experience that, barring
abuse or the odd failure of a component, the first things to go will
be the power supply capacitors, and from experience, they will last 15
to 20 years. Fortunately they die gracefully and are easily replaced.
After that, the longevity will depend on the number of operating
thermal cycles, but I can say that I have had amplifiers operating in
the field in excess of 20 years with no particular mortality except
capacitors. The answer is, I don’t have good information beyond
that. More to the point, I would suggest that you not worry about
it. This is a conservatively built industrial design, not a tweaky tube
circuit run on the brink. If it breaks, we will simply get it fixed, so
sleep well.
Fun Hardware Facts
