The LPS is an excellent sounding 12AX7 and are used in all Komet
amplifier models. The
re-issue
Sovtek
Mullard 12AX7 is another excellent 12AX7 option. With this factory stock
tube compliment, the Komet
Songwriter sounds powerful, complex and detailed. The
distortion is balanced and harmonically rich.
Please note
: you may find that some pre amp tubes, whether newly manufactured, used, or
even n.o.s., may be too "
microphonic
" for the first gain stage
(V1)
of a Komet
amplifier. A
microphonic preamp tube is a condition in which a tube will absorb mechanical vibration and
amplify it into the audible range. In this scenario, a tube can "
feed-back
", or give off a loud,
high pitched squealing noise
.
"
Feed-back
" can occur intermittently, even without an
instrument plugged into the input of the amp. This does not mean that the tube
(
s
)
are
completely unusable. One possible solution you can experiment with is moving the
microphonic tube to the
V2
phase inverter socket where microphonics are not as noticeable.
The microphonic 12AX7 may be quieter in the
V2
position as opposed to the
V1
position.
Please note
: a small amount of "
hiss
" is normal for high gain amplifiers. An excessive
amount of hiss, especially when the volume control of the amplifier is all the way down and
with no instrument plugged in the amplifier’s input, usually denotes a bad pre amp tube.
Some n.o.s. audio tube suppliers offer "
select
", or hand picked pre amp tubes, which are
superior in all aspects of quality, especially when it comes to being quiet and non-
microphonic.
Please note
: your amplifier produces heat. Prolonged gigs, outdoor or non-climate controlled
venues, only multiply that factor. We suggest
(after extended periods of play)
that you allow for
a sufficient amount of time to pass so as to let your amplifier cool down prior to moving or
loading. This action will help protect and extend the lifespan of the audio tubes and internal
components from excessive vibration or damage.
Caution
: please pay close attention when extracting and installing the power and pre amp
tubes. The pins of the tube -
must align perfectly
- into the tube’s socket. Bent pins,
especially when forced into a tube socket, can cause serious damage to an amplifier’s tube
socket pin inserts
.
99% of the time this results with the tube socket needing to be replaced.
To avoid this contingency, we recommend that you purchase a miniature pinned, nine hole,
pre amp tube pin straightener. These can be found on line from many vintage tube retailers.
This easy to use device guarantees that your 12AX7 pre amp tube and 6BQ5/EL84 power
tube pins will be straight and aligned for socket insertion.
NOTE
:
Komet
Amplification’s
warranty
will not
cover damage done to a tube socket’s insertion pins from forced or
accidental mis-alignment / and or bent / crimped insertion pins.
TUBE REPLACEMENT
A noticeable deterioration in your amplifier’s overall sound is an indication of an imminent
tube replacement. You may notice symptoms such as "
muddy
" or "
saggy
" power chords, a
loss of tightness or "
punch
", a weak sounding treble and bass, and loss of certain sonic
frequencies or note "
bloom
". We suggest that you first start by replacing your power tubes.
Pre amp tubes can last a very long time, and do not necessarily need to be replaced as often
as the power tubes. However, we do recommend that you have your 12AX7s properly tested
by a technician between servicing.
Copyright 1999-2017, Komet
Amplification. Group, L.L.C. May not be reproduced in any form without express written consent from Komet
Amplification.
