By Mike Kropotkin
Are all NOS tubes the same? Not by a long shot. In Part 1 of this series, Mike
Kropotkin spells out the basics on NOS vs. boutique tubes, including facts every player
should know before spending big bucks on any tubes.
This first installment compares some NOS tubes to their modern production counterparts.
Later articles will include such topics as tube substitutions, rebranding, and counterfeit
tubes. Much of what will be written and has been written about tubes is very subjective,
and issues such as tone should be taken as opinions and not gospel.
What is an NOS tube?
New Old Stock tubes (NOS) are unused tubes manufactured several years ago (10-50 years for
most guitar amp tubes). These tubes were made in the US, Canada, and Western Europe up
until the 1980s.
What are JAN Tubes?
Most of the post-1970 production was for military use since lots of military
communications equipment still called for vacuum tubes. These military tubes were given
the JAN (Joint Army Navy) designation in most cases. JAN tubes come from specially
selected production runs with the intent to yield durable tubes that would be able to
withstand vibration and G forces common in fighter planes. Durability is certainly a nice
attribute to have in a guitar amp that gets schlepped from gig to gig, night after night.
Some JAN tubes are actually identical to their commercially released counterparts, which
happened to be of sufficient durability for military inspectors.
Will they Make My Tremolux Soar Too?
Arguably, JAN tubes were never specifically designed to yield strong tonal performance.
However, since many of these examples are identical to commercial tubes and others are
merely mechanically "beefed up" versions, you’d have to assume that many
JAN tube types sound very good. There are probably some JAN types that are sonically
inferior but this is largely a matter of taste and opinion.
A classic example of a fantastic guitar tube that could also be found in B-52 bombers
is the Tung Sol 5881 (a.k.a. 6L6WGB), which was standard issue in many of Fender’s
1950s tweed amplifiers.
Trust your Ears and Ask Your Amp Tech
In general, the production quality of NOS tubes is far superior to that of tubes produced
today in countries like China, the Soviet Union, and Yugoslavia. The metallurgy,
production techniques, and quality control were vastly superior. A possible reason is that
before solid state, the production levels were significantly higher. This economy of scale
made it more cost effective to produce a quality product.
This is not to say that all current production tubes are bad. Many have decent to
excellent tone. Some of the general complaints are microphonics, noise, and inferior
longevity.
Until recently, China had one particular 12AX7 type that was a fantastic guitar tube.
It was tonally excellent and had very low noise and microphonics (all tubes are
microphonic to some degree). The factory has since been re-tooled for producing CRTs for
computers, a much more lucrative business.
Yugoslavia produces another tonally excellent 12AX7/ECC83. This tube, however, has been
plagued by microphonics. Some batches have been known to contain 70% unusable tubes.
The Soviet Union [Svetlana] has a highly regarded 6L6GC, but many of these are
microphonic as well, right out of the box. I’ve heard complaints from users that even
if they’re ok initially, they may become microphonic after a few hours of use when
they’re no longer under warranty.
Boutique Tubes
None of the "tube companies" that advertise in guitar magazines are
manufacturers of tubes. They merely buy tubes from China, the Soviet Union, or former iron
curtain countries, and test them, label them with fancy logos, and sell them in fancy
boxes. A few of these companies get involved with the manufacturing process and make
recommendations for quality improvements.
The Bottom Line: NOS Prices vs. Boutique
NOS 12AX7As range in price from the low teens to close to $100 (depending brands and where
you shop). Most boutique 12AX7s are in the low to high teens.
At the low end of the NOS scale, tubes like JAN Philips/Sylvania, and JAN GEs are in
pretty good supply right now. In the $20s, you’ll find items like RCA 12AX7As. In the
$30 area, you’ll find the super low noise RCA 7025s (exact replacement for 12AX7As).
Moving into the $40s, Mullards and Amperex from Great Britain and Holland, respectively,
have strong followings in the audiophile markets. Some guitar slingers love Mullards in
their Fender and Marshall amps. The Amperex seem to work best in amps that are inherently
a little dark sounding and need just a little brightening up.
At the top of the range ($80-$100) are Telefunken 12AX7/ECC83s, considered by many to
be the Holy Grail of 12AX7s. These are a bit darker sounding than the other 12AX7s and can
work very well in Fender amps, which tend to be on the bright side.
Go with NOS
6V6GTs. There are very few offerings in the boutique market for 6V6s. The Russian 6V6 is
of extremely poor quality and, in many cases, won’t stand up to plate voltages found
in Fender silver and black face amps. The tone leaves a lot to be desired as well. These
are in the teens to $20 range per pair. One of the boutique tube companies is selling low
grade Russian 6L6GCs as 6V6s because they can at least tolerate the plate voltages and
stand a chance of "living" in vintage amps. These are going for about $20 per
pair.
NOS 6V6GTs range from the mid $20s to about $70 per matched pair. The low end is
represented by brands such as Hytron, GE, and Raytheon. The $30-$40 range will get you JAN
Philips, Sylvanias, Mazdas (a relatively unknown brand from France that is getting rave
reviews), and Brimar (from England). At the high end, $40-$65, you’ll find RCA
greyplates, Visseaux (another excellent French brand with a Marshally tone), and, at the
top of the heap, RCA blackplates.
The Crème de la Crème
6L6GCs. New production 6L6s include the ones mentioned above, which are most
often marketed as 6V6s, Russian "5881/6L6WGC" (which are actually neither 5881s
nor 6L6WGs), and better quality Russian 6L6GCs. Prices range from about $15 to $40 per
matched pair.
KT-66s, a super 6L6 modeled after the British KT-66 by MO Valve, are higher still.
NOS 6L6GCs range from about $55 per matched pair to $225 per pair. The low end includes
names like GE, Sylvania, RCA (grey plates which are actually manufactured by GE and
Sylvania), and JAN Philips. Tung Sol 5881/6L6WGBs are in the $90s and RCA black plates
(considered the crème de al crème by audiophiles and guitar freaks alike) run about $150
per pair.
Higher still are British KT-66s, which range from about $190 to $250 per pair depending
on the particular vintage. British and Holland made EL37s are also right up there.
Now, what does this mean to you as a player intent on squeezing every last bit of tone
out of your amps’ circuitry? First, understand that there are significant differences
in the quality control standards employed in modern tube manufacturing—"caveat
emptor" certainly applies here. Second, it is a fact that certain types of NOS tubes
are clearly superior to their modern counterparts—the question is, will you
appreciate the difference enough to justify the added expense? As with amps and speakers,
guitars and pickups, I suggest that you expose yourself to as many different combinations
as possible to find your favorite tubes among the many choices available to players today.
There is no substitute for personal experience.
