are they? They are valve-base decouplers which allow
you to mount a B9A tube (of the ECC83 / 12AX7 fitting)
on a compliant rather than rigid base.
first sight, these little beauties may not strike a
chord with the ‘Wow’ factor, but then, in
reality, they will most likely be tucked away, hidden
inside the dark (or in the case of tube pre-amps, not-so-dark)
recesses of the outer casing.
Gels are simply add-ons. They have on the bottom 9 pins,
just like the base of a 9-pin valve. There is a squidgy
centre part, and in the top a 9-pin valve socket. Their
overall height is about 18mm when inserted, but their
beauty lies not in their appearance, but in their performance.
They take some burning in, and the first twenty hours
or so are a tad so-so, but once warmed through they
start to reveal their virtues.
in the annals of the past many pre-amps used valve bases
decoupled from the chassis by a very compliant rubber
insert. Although the pin-connection part was relatively
rigid, as were the base’s mounting points, the
rubber between the two was distinctly pliable. This
meant that, in the days of all-metal construction, the
‘ringing’ characteristic of the chassis
could be virtually eliminated. The venerable Quad QCII
was one such among many, though the 22 dispensed with
them. I have in fact converted one 22 to use the original
compliant mounts a la QCII with amazingly good results.
the Absorb Gels are even better. The noise floor is
lower. The hint of ‘clang’ is entirely absent,
and the feeling of openness and space in the musical
presentation is enhanced to a great degree.
also work extremely well in phono stages, where the
additional damping and ‘gentle restriction’
of the tube does wonders for all that elusive low-level
detail. Gone is the metallic or ceramic hash of rigid
mounting, replaced instead with a liquid involving and
musical presentation. Dynamics are decidedly NOT compressed,
and feel even more vivid than before, and the range
of tonal colour is enhanced beyond a standard base.
only area where you have to be careful in a pre-amp
is in the available height above the original tube base.
If clearances are tight, you may not be able to fit
them, but if you can, then do. They are an investment
really worth hankering after, and for a very modest
outlay, you won’t want to go back to ‘standard’
power amps, where a B9A driver or phase splitter tube
is used the effect is similar, but to a lesser degree.
In these situations the tubes are usually carrying larger
signals with respect to noise, so the benefits feel
a little less marked, and their effect on power tubes
(EL84 / 6BQ5) was less pronounced again. It was still
there, but although I had no problems using them under
EL84s, the high temperature of the EL84 made me query
their ultimate suitability in this particular application.
this is a five-star ()
product. For a relatively modest outlay a significant
improvement can be achieved, and this can be transferred
from pre to pre as your mood takes you.
word of warning, however. Don’t expect these gizmos
to transform your dull-grey preamp into a technicolour
one, but do look out for more music, and longer listening
sessions. And do be prepared for a higher electricity
bill, though, as you may be a lot more reluctant to
turn your system off after they have been run in.