Ver. 1.1 - ©Phædrus Audio Ltd. 2011 All rights reserved.
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Situate the Phædrus Audio equipment away from heat sources or other equipment that
produce heat.
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Ensure Phædrus Audio equipment has adequate ventilation. Improper ventilation will cause
overheating, and can damage the equipment.
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When cleaning Phædrus Audio equipment, remove all connections to the unit; including
power and gently wipe with a clean lint-free cloth; if necessary, gently moistened with
lukewarm or distilled water. Use a dry lint-free cloth to remove any remaining moisture.
NEVER use aerosol sprays, solvents, or abrasives on Phædrus Audio equipment.
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Phædrus Audio equipment should be serviced by qualified service personnel or returned to
Phædrus Audio Ltd. when: an object (or objects) have fallen into the enclosure; or liquid
has fallen into, or been spilled into the unit; or the unit has been exposed to rain or high
humidity; or the unit does not operate normally or exhibits a marked change in
performance; or the unit has been dropped, or the enclosure has been damaged.
Chapter 4 - About Valves (Vacuum Tubes)
Valve (tube) types
The Phædrus Audio PHAB and PHAME preamplifiers
employ an EF86 pentode input valve (tube) and an ECC88,
or E88CC, valve (tube) as the output device. Positions for
the valves are very clearly marked on the PCB silkscreen
as indicated in the illustration. The valves (tubes) that
are installed in Phædrus Audio’s products during
assembly are selected to give the best possible
performance. We offer versions of all products with NOS (rather than current production) valves.
But these must be chosen carefully, and be pre-screened. Replacing the supplied valves (tubes)
with different, collectible, or “high-end” valves (tubes) types may not affect any improvement and
might cause deterioration of performance.
EF86
The EF86 is a low noise pentode, originally manufactured by many different factories and
branded by Philips, Mullard, Telefunken, Valvo, and GEC, TESLA and Siemens/RFT. Many
NOS valves are still available. Equivalents include the CV2901 (the UK service designation
for the EF86) and the CV4085; a special quality version for military use. The EF86 tube is
still being produced in Russia and in the Slovak Republic under JJ Electronics brand name
(formerly Tesla). Chinese close equivalents are also still being manufactured.
ECC88
The ECC88 is a frame-grid, sharp cut-off, twin (dual) triode with an internal,
separating screen. The valve was originally designed for service in the front ends of
VHF radio receivers. The ECC88 (E88CC) tube type is equivalent to the North
American 6DJ8 tubes and the (rare) military branded CV2492. The transposition of
the figures from ECC88 to E88CC was Mullard's way of denoting a special quality
build and is equivalent to the US 6922. Russian 6N1P tubes and the Chinese 6N1
tube are NOT equivalent.
NEVER install a 6N1(P) in the Phædrus Audio PHAB or
PHAME product
. The ECC88 valve is sill being manufactured in China and in the
