OUTPUT TUBE WARNING
The SE84ZS is designed to use either EL84
output tubes or SV83 output tubes. No adjust-
ments are needed when switching from one to
the other. Of the type SV83 tubes carrying the
Svetlana name there is one batch known to be
questionable and ARE NOT RECOMMENDED for
use in this amplifier.
The tube on the left is an acceptable SV83
output tube for use in this amplifier. The tube
on the right with the smaller logo is NOT accept-
able for use in this amplifier.
OTHER OUTPUT TUBE INFORMATION
This amp ships with the milspec version of the SV83
This ultra high quality tube features a 5000 hour rat-
ing, and is known only by its REAL Russian numbers
6P15P-EV or 6n15n-EB
If there is no extension of -EV or -EB it is not high
grade version and likely a standard SV83.
The number SV83 came from an American marketing
company who purchased a large stock of the non-
military grade of these tubes and then made up the
trademark of Svetlana and the "S" logo visible in the
These tubes whether milspec or non-milspec are
because of their small size and intended use in
video applications are superior sonically to the pop-
ular 300B, 2A3, 45's because they lack the heavy
signature and are considerably faster. The band-
width of these tubes is far greater then that speci-
fied for audio tubes.
The SV83's and the 6P15P-EV tubes all came from
a single tube factory in Russia and were manufac-
tured in the 1980's.
Decware was introduced to these tubes in 1995 by
Svetlana's Eric Barbour who was convinced they
would make a nice alternative to the EL84's.
Steve Deckert, owner of Decware and designer of
this amplifier was the only one in the industry
smart enough and with the foresight to purchase
and use these tubes. To date we are the only
manufacture to use this Vacuum Tube in produc-
tion high fidelity amplifiers.
Now that the company Svetlana is gone, Decware
purchases these tubes directly from Russia and
with only original factory markings on the glass.
Always buy 6P15P-EV replacement tubes directly
from Decware. You may also enjoy EL84/6BQ5
tubes of which there is a huge variety of, from any
reputable tube supplier.
Output tube life is rated at either 3000 or
5000 hours depending on the type tube
Rectifier tubes can easily last the life of
Input tubes will vary from tube to tube
and should be checked yearly.
The easiest way to check input or output
tubes is to replace them with a known
new set and compare both sound quality
and power output of the amplifier. If you
hear very little difference, the tubes are