Machine
Gun Amps
Tube Descriptions
All tubes listed here are
either new production or New Old Stock
("NOS
means New Old Stock which are old tubes that have never been used. If a
tube is used, it is not "NOS", it is used! Don't be fooled...)
Notice: I
am not selling any tubes anymore.
I will
attempt to describe the sound that they give and the application they are
for. For tone considerations and what you should think about before
you buy new tubes, go here. I also have experience
with other tubes. Look at the
page.
What tubes does my amp use?
Power Tubes (not for sale)
Preamp Tubes
Rectifier Tubes
Power tubes (not for sale)
Svetlana
6L6GC
This is a great new tube. It's only been
in production for a few years, but it's been very reliable and good sounding.
It appears to be very sturdily constructed, like the old American and European
tubes. The sound is like a classic 6L6GC, more in RCA and GE territory
than Sylvania STR. They have the nice balanced sound and nice high end
of the classics. They don't quite have the punch and headroom of the Philips
7581A, but what does? These are definitely worth consideration if you like
classic 6L6GC tone. I've been using them almost exclusively in 6L6 amps
because it's my opinion that you really don't need to spend the extra cash
on the NOS tubes as far as quality is concerned. But the NOS tubes I
carry do have a different tone so they still warrant consideration. I use
these in some of my own amps.
Ruby
6L6GC STR
I have started carrying this tube as an
economical alternative to the other 6L6's. This is a nice sounding tube
and the quality seems to be getting better and better. Ruby's guarantee
is the best there is, so that should be enough reason to check them out.
The sound is similar to the Svetlanas, but maybe not as "refined". These
are supposed to be knockoffs of the classic Sylvania 6L6GC STR tube that
came in 70's Fenders and Boogies, which is generally considered the best
of the high power 6L6GC's ever made. That tube is still available as the
7581A down below. To compare these Rubys to the Sylvanias is a bit optimistic,
but they are good nonetheless. If you don't want to spend the extra money
on the other 6L6's, there's absolutely no shame in buying these! I use
these in some of my amps.
JAN
Philips 6L6WGB (5881)
This is a newer version of the famous
5881 from the late '50's early '60's. 5881's are the tubes that came stock
in many of the late 50's Fender tweeds. These have the small bottle like
the old Tung Sol, in between the size of the 6V6 and 6L6GC. These have
a bit of a harder and stiffer tone than the Tung Sol 5881, but try finding
a Tung Sol! These tubes emphasize midrange and break up earlier than the
other 6L6GC types. They sound better to my ear in tweed amps, but still
do fine in blackface and silverface amps. They give earlier breakup in
blackface and silverface amps when compared to the 6L6GC. I find that they
work well in the 6V6 to 6L6 Deluxe mod. They
are very well suited to this job! They also work well in Fender Blues Deluxe/Devilles.
These are nice tubes! This tube comes in a white box with military stock
numbers on it.
Here's an explanation of what the letters
mean on the tube: G means it's a glass tube (instead of the older metal
ones). The first 6L6 was metal, then they went to 6L6G which was a glass
bottle version. That could be considered the 6L6GA. There were other variants
from there. Then came the 6L6GB. B is the version. It was more of an evolution
than anything else. The military version of this tube is the 5881. It is
rated a little higher than the regular GB. In the later years, companies
sometimes attached a W into the tube number rather than using the military
designation, hence the 6L6WGB. It's basically a 5881. The JAN means Joint
Army Navy. I'm not sure exactly what that means, but it does mean that
these are tubes that were made specifically for the US military.
JAN
Philips 7581A (6L6GC)
This is the mil spec version of the Philips
6L6GC. These are world class tubes, bottom line. It has double mica spacers
but otherwise looks and sounds identical to the famous Sylvania 6L6GC STR.
The Sylvania 6L6GC STR is the tube that Fender requested to be made specifically
for hanging upside down in guitar amps. These are also the tubes that came
in original Boogies. The tone is very up front and clean. They do distort
nice though. Think SRV type tone when they do distort. They retain the
high end bite. This tube sounds very nice in blackface and silverface amps,
particularly Twin Reverbs. It's considered among the best 6L6 type ever
made. This tube comes in a white box with military stock numbers on it.
Svetlana
EL34
This is a very nice tube, with quality
in construction you'd expect from Svetlana. The tone is a little more bottom
endy compared to the Siemens EL34 and the Sovtek EL34WXT. These work particularly
nice in combos where you need the extra bass and not quite as much high
end. But pumped through a 4x12 of Celestions, they are very, very nice.
These are the only EL34's I'm stocking right now, although I can get others.
You owe it to yourself to try these before you search out some really expensive
NOS ones! Here's my take on EL34's: They belong in Marshalls! Some
people like the way that they sound in Fenders and I'll give them that.
But the reason why Fenders sound like Fenders has a lot to do with
the 6L6's. Besides, installing EL34's in your Fender (which requires mods
by the way) will put extra strain on your power transformer due to increased
filament draw. There's no guarantee that your power transformer will survive!
JAN
Philips 6V6GT
NOS 6V6's? You bet! These sound great
and appear to be made really well. They should be, they are US military
tubes! They have pretty, shiny black plates. They have a bit more clarity
and high end than my beloved GE's. I may even like these better than the
GE's now that I have a bit of experience with them. Highly recommended
for up front 6V6 sound. Sure they are expensive, but your Deluxe Reverb
or other Fender 6V6 amp deserves nothing less than good ol' military stocks!
This is my new standard for 6V6's in my own amps! This tube comes in a
white box with military stock numbers on it.
Ruby
6V6GTBC
Finally! A new manufacture tube that will
survive in your Deluxe Reverb! These tubes are much more rugged than the
Sovtek. They sound nice, but not as strong as the JAN Philips. More in
RCA territory than JAN Philips. I've been using them in my project and
they have survived some extremely merciless pounding by me. Definitely
worth a try if you are searching for a 6V6 you like. These are likely the
cheapest matched new 6V6 you will find. For the money, they can't be beat!
Since it's Ruby labeled, you know they stand behind it too. Comes in a
Ruby box with matching specs.
NOS 6K6GT
Get these while they last. I'm not sure
if I'll be able to hold the price this low, but all the ones I have left
will be sold at this price. This is the tube you need in your original
or reissue Fender Reverb Unit! It really
does make a difference folks. It takes part of the splashy, bitey sound
off the RI and makes it sound more like an old one. I usually have a few
RCAs and other brands too. Email me
for details.
Preamp Tubes
JAN
GE 12AX7WA
These are the military spec 12AX7. They
are a direct replacement for the 7025 as well. This is a nice sounding
tube. Very evenly balanced to my ear. Nothing fancy, they get the job done.
These are practically identical to the Fender labeled GE 12AX7/7025 that
came in late '70's Fender amps. Rumor has it that Eric Johnson uses these!
These don't emphasize highs or lows, they just reproduce the sound like
it should be reproduced. I like them a lot. The main reason I like them
is because they are very tough. I haven't had any experience with newly
constructed tubes that last anywhere near as long. These should last AT
LEAST twice as long as run of the mill Chinese and Russian garbage. And
they don't go rattly or microphonic like the cheapies! Why bother spending
more on a Groove Tube that is really foreign when you can have good ol'
American Military stock? All of these are tested by me in my amps at high
volume. I also tap on the tube to try to drive it into microphonics. This
tube comes in a white box with military stock numbers on it.
Tesla
ECC83/12AX7
This is my new lowest noise tube. Yes,
even a TAD lower than the JAN GE. Since the Ruby 7025STR has been out of
production, this is the now the best of the new manufacture 12AX7's I carry.
This tube tends to accentuate the high end a little. They make individual
notes cut through a little better than the JAN GE and Ei. This is nice
for livening up a semi dark amp. These would be good for getting that high
end crunch and harmonics in high gain amps. The tone of the Ei seems
to be a bit more complex in the mids. But this tube is definitely interesting.
The ones I have now are remarkably free of noise and microphonics. The
plate structure is different looking, not like a normal tube. But they
seem to be good and if they last, I will continue to carry them! I'm going
to experiment with them in my project amps and do some more tone testing.
Tesla is making some of the best stuff quality wise these days. They come
in either the standard JJ/Tesla box, or a Ruby box.
Ruby/Ei
12AX7/ECC83
Guess what folks? The factory that made
these tubes was bombed in the NATO joint bombing thing. These were tubes
made in the former Yugoslavia. I used to carry them as a cheaper option
to the JAN GE's, and also because they have a different tone. To my ear,
the Ei's have more high end and more gain. Kind of sounds like the presence
got turned up. They work nice when the amp is going to be pushed to distortion.
A lot of people like the tone of these as well as some NOS tubes! As a
matter of fact, these are causing a bit of a stir in the hi fi circles.
I've found that a few of them go rattly after some time has gone by. For
this reason, I'm going to offer the Tesla as an upgrade. Hey, these are
not US military tubes! But they are much better than the standard Russian
and Chinese stuff in my experience. Don't feel like a cheapskate buying
these! They have a different tone compared to NOS. And they do sound nice!
I'm using these more and more in my own amps. I weed out the bad ones by
testing them in my Marshall.
JAN
Philips 12AT7WC
NOS are the only 12AT7's I use at the
moment. I haven't found any current made ones that are worthwhile. I started
carrying these due to a few problems with the JAN GE's. It seemed that
I would get one or two bad JAN GE's in each order I would make (I found
the bad ones in testing). Then I started to get more and more bad ones.
The price I pay on these is too high for bad ones! I'll probably order
the Philips from now on since their success rate seems to be much better.
Tone doesn't seem to be much different, if at all, compared to the JAN
GE. The main consideration of this tube should be reliability anyway. This
is why I like to use NOS 12AT7's! I test all of them in whatever Fender
reverb amp I have in front of me at the time, usually the Deluxe Reverb.
They get tested in the reverb driver. Whenever you change power tubes,
you should change the phase inverter as well. The phase inverter is the
closest small tube to the power tubes in Fenders. Blackface and silverface
Fenders use 12AT7's as the phase inverter in most amps. This tube comes
in a white box with military stock numbers on it.
GE
12AT7
I scored a few of these and they are cool.
One more tube to choose from! These tubes are identical in construction
to the tubes Fender used in their amps in the late '70's with the Fender
label. These are actually the 12AT7's that I use in my own amps. They are
packed in generic white boxes. The tubes themselves have no white GE ink
like is typical of tubes made in this period, but they do have the grey
sandblasted on printing that immediately gives them away as GE's. As far
as I can hear, the tone is identical to the JAN GE 12AT7WC. These are not
built as stout though. They share the same plate structure as the JAN tube
(or it looks like it does), but it doesn't have the double or triple mica
spacers and general robust construction. The JAN tube also has extra support
to hold the whole assembly together inside. It may be worth the extra money
if you are on the road or hauling your amp everywhere all the time. These
have been working fine for me. However, if you want the ultimate in 12AT7
tubes, the JAN Philips are still the ones. Go with these if you want NOS
tubes but don't need the absolute ultimate in longevity and toughness.
JAN
GE 6072A/12AY7WA
This is the tube that came stock in many
tweed Fender preamps. The gain of this tube is lower than the 12AX7, 12AT7,
and 5751. A lot of people would replace this tube in their tweed amps with
a higher gain tube to get more crunch. However, some people like the amps
to sound the way that they were supposed to sound when they left the factory.
To get the original tone, you need this tube! These are US military tubes
made by GE, so you know they are good. This seems to be the only one I
can get in any kind of regular quantities too. These have pretty shiny
black plates that remind me of my GE 5 star 5751's. I test them all in
my Marshall for noise and microphonics. Make your tweed Bassman, Pro, Deluxe,
Super etc... sound like it's supposed to sound! This tube comes in a white
box with military stock numbers on it.
JAN
GE 5751
This is the "option" tube (a little lingo
lifted from CART racing from last year...). These can successfully be used
to replace any tube in the preamp of a blackface or silverface Fender in
a pinch, but are not really suited to the reverb driver position. I'd really
recommend using it in the first or second position only (looking at the
back from the right) depending on what channel you use. They have less
gain and possibly less high end than a 12AX7. The gain factor of a 12AX7
is 100, the 5751 is 70, and the 12AT7 is 60. I like the 5751 if clean is
the order of the day. I have a buddy that I run these in the preamp for,
because he plays country and wants the amp to stay extra clean. It also
helps because he uses high output G&L ASAT's. These things can also
smooth out an amp with too much gain for your tastes. Use the 5751 as something
different to try. These do work nice in a slot originally designated for
a 12AY7. If the 12AX7 is too much for you, these are halfway in between
the 12AY7 and 12AX7 on gain. They sound nice in the first position of a
tweed Bassman! These tubes are rated to draw a bit more filament current
than a 12AX7 or 12AT7. This shouldn't be a problem in an amp, but I'd be
a bit leery of using this tube in a tube pedal or otherwise non stout preamp
or something. I test these for microphonics and rattle in my Marshall.
This tube comes in a white box with military stock numbers on it.
JAN
Philips 6189/12AU7WA
This is a mil spec 12AU7A. This tube was
never used normally by Fender as I recall. However, I have seen this tube
specified on the tube chart of a tweed Super. The "Y" in 12AY7 was crossed
out with a pen and replaced with a "U". This crossing out of letters on
Fender tube charts is something that is widely accepted that Fender did
in lieu of printing new tube charts. Since I've seen this tube specified
in a Fender amp, I'm going to stock it! Some Ampeg, Vox and Gibson amps
came stock with this tube. This tube would make a good reverb driver in
a Fender if you like the tone, it's able to handle the plate wattage fine.
I've finally done some testing on this tube, and it does sound nice in
the reverb driver slot. It seems to give a bit more depth than the 12AT7.
It also seems to run very hot, but this is probably due to the bigger plates
absorbing more heat. This tube is probably not something that you'd want
to use in the signal path very often due to it's low gain (about half of
what the 12AY7 is), but it makes a really nice reverb driver where gain
is not important. The 5814A is also a mil spec 12AU7, but my handy GE tube
manual shows that these draw a touch more filament current and can handle
a very slight bit less plate wattage, so I'll probably stick with the 6189
while they are available. This tube comes in a white box with military
stock numbers on it.
Rectifier Tubes
(I also carry other rectifier
tubes on my rectifier tube page.)
Chinese
GZ34 (5AR4)
This is the only new replacement GZ34/5AR4
tube that is available. You can still get NOS, but at $60 a pop or so,
I'll keep away. Since this tube has nothing to do with tone intrinsically,
longevity and reliability should be the only concern for this tube (more
on that below). You are not going to be able to tell tone differences between
the Chinese and Mullard GZ34/5AR4 provided that they are giving you similar
B+. I've found that the reliability on the Chinese GZ34/5AR4 is good so
far, and they seem to give decent life span. I use these in all my own
amps. The only problem I've had lately is that they tend to rattle. It's
not a problem at high volume, but if you record at low levels in the studio,
it may be a problem.
Now, onto the tone thing. There is no tone
inherent to the rectifier tube. You read
that correct. A Chinese GZ34/5AR4 will sound exactly the same in your
amp as a $60 Mullard. The function of the rectifier tube is to help
turn that AC voltage coming out of the wall into DC. There is no signal
going through the rectifier tube. This tube does affect tone in an indirect
way, it sags. Since the electrons in the tube have to cross a gap, this
acts like a resistor. The harder you play the amp the more it will sag.
The GZ34/5AR4 has a spec on the amount of gap between the cathode and the
plate (which is what determines how much sag you get), and theoretically
this gap is the same in the Chinese and Mullards. The only benefit you
will get from the big dollar NOS is increased tube life or bragging rights.
Is this worth it to you? Maybe. Also, other rectifier tubes will sag more,
like the 5U4 or 5Y3. These have a larger gap than the GZ34/5AR4 which causes
more sag. However, these are NOT direct plug in replacements contrary to
what you may have heard. These different tubes will change voltages throughout
the amp and will usually need a bias check/adjust to make sure your amp
is working properly. Also, sometimes the voltage change is not a good thing.
If you have a Princeton Reverb or silverface Deluxe Reverb that uses
a 5U4, I'd recommend against using a GZ34/5AR4. Go here
to read about subbing different rectifier
tubes before you go ahead and do it.
Mullard
GZ37
I have decided to start carrying a few
of these. They are NOS British military stocks. They make a wonderful alternative
to a 5U4GB and are nice in place of a GZ34/5AR4 if you want less voltage.
Watch out, these do draw 3 amps on the filament like a 5U4GB though. An
amp originally designed for a GZ34/5AR4 might not like this tube. They
are indirectly heated which will ramp up slower and help extend tube life
if your amp doesn't have a standby switch. These things sould last years
and years, long enough to forget about chaging it for a long time. They
sure are pretty too. They are in a really tall bottle with a shoulder on
top and a brown base. They come in a British military box. 5U4GB users,
this could be your new tube.
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Last updated 11/17/00