I've been experimenting for years working
to find the right mix of good sounding and reliable 6L6 tubes to stock here at
the shop. After installing thousands of tubes, here are my three top picks and
why.
Top choice - 6L6GC from "Winged C".
This Russian tube has good power
output, good reliability and great tone. It's the brightest sounding (most
treble) of the three and has a little less bass than the others. The bass is
tight, punchy and clean while not overbearing. When overdriven, the tube takes on a "sparkly" sound.
The only negative about this tube is that the price has recently risen much
higher than any other current production 6L6GC. This is
the brand that used to be called Svetlana but they no longer use the name in
North America because another company has purchased the name usage rights. The
tube labeled "Svetlana" is different and in my opinion, is an attempt to mislead
tube buyers.
Second Choice – Tung-Sol 6L6GC STR.
Also from Russia, this tube has only
been around a couple of years. It’s built by the same factory that makes the
Sovtek and Electro-Harmonix tubes but the Tung-Sol tubes from this factory are
generally built more solidly that the other brands they offer. The glass
is thick and like in the
Winged C,
the plates are welded and the entire guts of the tube are suspended by “springs”
to reduce vibration and microphonics. The tone is a bit less bright than the
Winged C and it has slightly more bass. The overall volume and clean
headroom is slightly lower
since the tube breaks up a bit earlier in the volume range. The breakup
(clipping) is very smooth in this tube. It’s a good choice when you want to
tame a harsh sounding amp or if a little less volume is desired before
distortion. The price is in the mid range for current 6L6 tubes.
Third Choice – Sovtek 5881WXT. This
Russian tube is not a true 6L6 or 5881 but a rugged design made for military
use. This one comes standard in
many new amps and is sometimes seen with a Fender or Groove Tube label. The tone is not outstanding but it mates well with some
amps, especially overly bright-sounding amps. Treble content is somewhat
reduced and lacking in harmonics. There is ample bass but it can tend to get a
little loose and flabby in the bottom when pushed, especially as the tube gets
old. You may wonder why I listed this as a top pick. It's because
the tube sounds reasonably good, it's very reliable (even in high voltage amps)
and the price
is lowest of the three picks so it’s a excellent value. In fact, it’s about
half the cost of the Winged C. The maximum plate dissipation is 22.5
watts so bias must be adjusted for lower idle current than a Standard 6L6GC.
There are several other good sounding 6L6 tubes available
such as the JJ 6L6GC from the Slovak Republic and the TAD 6L6GC
and Valve Art 6L6GC from China but because of consistent quality problems, I
will not be stocking them.