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I
can provide tested and selected vacuum tubes for
Counterpoint and Alta
Vista Audio upgrade products.
To find out what tubes your unit uses, find your product on
the list below, click on it and you can see which tubes it uses. In
some cases there are more than one possible type of tube that can be
used. Click on the tube type to view pricing, availability and other
options.
If you want a list of other companies that sell tubes, go to
Firebottle Audio's
site -- there are several vendors listed there.
Counterpoint
Products
Alta Vista
Audio Upgrade Products
- 6DJ8/6922 Type . Used in most line
stages and many phono stages, and in the majority of the power amps I
designed. See chart for pricing.
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| 6DJ8 (6922) Types |
The "EH" version of the 6922 is the only tube of this type still in manufacture. Suitable for
everything from pre-preamp, through phono to power amps, it is
affordable and sounds very nice. This tube
offers consistenly good value in terms of tonal balance,
musical involvement, transient "punch," bass impact, warmth and freedom
from glare and "hash." I purchase these tubes in large lots and sort them, measuring
noise, susceptibility to microphonics, gain and grid leakage. About
half are not suitable for much of anything. Those left over I offer in four
levels for these applications.
If you are seeking the very best sound, this article on my Aria Audio website might be of interest.
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Grade |
Price |
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6922AAA - Reference Grade
For
Pre-Preamps.
The quietest tubes with the lowest microphonics in the bunch. Fully
tested for low noise (less than 10uV noise and no microphonics), both
halves tested for matched transconductance. These tubes are exceedingly
rare, only about 4 out of every 100 tubes make the cut.
They are suitable for the lowest noise applications and for test
purposes, as there are no 6922-type tubes (including 7308, 6DJ8, ECC88,
E88CC, ECC288, etc.) that are quieter than these hand-selected gems.
They are as quiet as is theoretically possible for this type of
tube. |
$120 |
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6922AA
For Phono
Stages.
Not as quiet as "AAA" tubes, and not as impervious to vibrations, but
don't "ping," or "ring" when tapped. Less than 16uV noise and very low
microphonics, Both halves tested for matched transconductance. Suitable
for phono stages and other very low noise applications.. |
$70 |
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6922A
For Line
Stages.
A bit noisier still, but well below 22uV of noise. More likely to
"ring" when tapped, but in a line stage application it will not be
noticeable -- unless you tap it. Less than 22uV noise, both halves
tested for matched transconductance.. |
$45 |
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6922B
For Power Amps. Less than 28uV of noise. These tubes will "ring" when tapped, but given
that a power amp is not followed by any further amplification, it will
not likely be audible. |
$10 |
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NOTE: These
descriptions are guidelines only. If you are using very efficient
speakers, and/or are sensitive to microphonics or ringing, always use
the next higher grade of tube. |
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- Alternatives to the 6DJ8/6922 for
Line Stages and Power Amps. For different sonic preferences I can
suggest several other choices. I do not stock these other tubes, you'll
need to hunt them down yourself.
- 7308/E188CC/8223/E288CC, CV5358, 6922-WA, CCa,
CV10320, CV2492, CV2493, CV8065, E88CC, E88CC/01, ECC868, CV5231,
CV5354, E188CC tubes are equivalent to
6DJ8/6922 types and can be used in place of them in all Counterpoint
equipment. They are usually too noisy and/or microphonic for phono
stages.
- Neither the Russian 6N1P nor the 6N(H)30 tubes are good choice -- they require much more filament
current, 600mA and 825mA respectively, than the 350mA that the
6DJ8-type tubes require. This increased load on the filament supply
would likely damage the filament voltage supply circuit.
- 6CG7/6FQ7 tube can also be used in place of the 6DJ8
in line stages and power amps. Usually presenting a softer, more
rounded, classic triode sound with fat, deep bass. However, the RCA
"clear top" is very well-balanced and nice to listen to. Again, these
tubes are generally too noisy and/or microphonic for phono stages.
- For a good review of the many 6DJ8-type tubes, see Joe's
Tube Lore on Audio Asylum at http://www.audioasylum.com/audio/faq/joes-tubes.html#6DJ8
12AX7 Types. There are dozens of
12AX7 type tubes available. I have two types that I stock.
- Chinese 12AX7A. A perfectly fine-sounding tube. $15
each.
- Sovtek 12AX7LP is extremely nice. This tube has a
nice fat neutral sound. You can also get them from the New Sensor site
at www.newsensor.com .
6CA4 and other 9-pin rectifier types that
can be used. Just
as aftermarket AC power cords, which go between your product and the
wall outlet, affect the sound, sometimes dramatically, rectifier tubes
(which go between the audio circuitry and the power transformer, which
then goes to your expensive aftermarket power cord then to the wall
outlet) can make a huge difference in the sound quality.
There are several types of 9-pin rectifier tubes
available. If your Counterpoint product used a 9-pin vacuum-tube
rectifier (was I the first in high-end to use a tube rectifier? 1981,
the Counterpoint SA-2 pre-preamplifier) then it would have originally
come with a 6CA4/EZ81.
Important points about 9-pin rectifier tubes:
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In Counterpoint gear which uses 6CA4's, you can also use 6V4/EZ80's, which can be plugged right in.
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6BW4's
can also be used but they require modification to the tube socket
wiring (pin 3 needs to be connected to pin 9 -- don't do this yourself
unless you know exactly what you are doing!).
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Some
rectifiers sound a lot better than others, but you can't go by tube
type or brand. There are good-sounding 6CA4's and bad-sounding 6CA4's.
There are good-sounding 6BW4's and bad-sounding 6BW4's. There are
good-sounding 6V4's and bad-sounding 6V4's.
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As
of December 2005, I have found 24 different versions of these three
types of tubes. They are all built differently internally. Tubes with
different inner construction all sound different.
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You
can't tell if you have a good-sounding version or a bad-sounding
version by reading the brand label printed on the tube. The only way to
tell one tube type from another is to inspect the internal construction
visually and ignore the printing.
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Read this again: The printing on 9-pin rectifier tubes bears no
relationship to what's inside. I've found identical tubes (as
determined by inspecting the inner parts like plate structures,
getters, etc.) labeled with totally random brand
names. I have many different tubes (with completely different inner
parts) that are branded the same. The names "Mullard," "Sylvania," and
so on mean nothing on 9-pin rectifiers as far as I can tell. It is impossible to determine
the original manufacturer of the different types.
When
I receive a batch of tubes I inspect them, identify them by their
inside parts (I keep examples of each variety on hand), and sort them.
New tube varieties (one's I've not seen before) are listened to as soon
as possible to evaluate how good they sound. I update the quantities on
the chart (below) to try to keep it current.
I offer 9-pin rectifiers in six grades. The very
best grade sounds far better than any of the tubes originally used in
the Counterpoint equipment. The lowest grade can be used to keep a unit
running, but are not upgrades. The higher a tube is in the chart,
the better I think it sounds.
TO ORDER: Just tell me the "order number" of the tube you want. Order numbers are on the chart below.
"C" refers to 6CA4/EZ81 types, "V" refers to 6V4/EZ80 types, and "B"
refers to 6BW4 types. "C" and "V" tubes can be used in Counterpoint
gear without modification; "B" tubes require modification.
6CA4 and other 9-pin rectifier tube options for Counterpoint |
Note the new "V8" type -- so good that it has received an AAAAA rating!
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Grade |
Order Number* |
Description |
Qty. In
Stock |
Price |
AAAAA
(amazing) |
C
8 |
6CA4/EZ81.
The V8 tube, below, was the best rectifier tube, by far starting Nov
2005. I was able to provide the V8 type to customers until May 2007,
when we ran out. I found what I thought were the same tube from the
same vendor, but when they arrived, we noticed that they were labeled
"EZ81,"and while they the same exact internal construction as the V8
type (see below), they are taller. I was concerned that they would not
sound as good as the V8 tubes, but careful listening shows that they
sound every bit as good as the V8 tube. Same manufacturer, same
materials, same construction. Got lucky this time: like the V8, the
most natural sound I've ever heard. Cables costing 10 times as much
won't improve your Counterpoint as much as this tube will. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) ADDED 30 May 2007 |
9 |
$135 |
AAAAA
(amazing) |
V8 |
6V4/EZ80.
Until hearing this tube, no other rectifier sounded nearly as full and
present as the AAAA tubes (below). But this one left us with dropped
jaws. Totally engrossing sound: full, round, detailed, and extremely
present -of all the rectifier tubes, this offers the most natural sound
I've ever heard. Is is an odd-looking 9-pin 6V4-type rectifier with a
fat bottle & plates stacked at right angles to each other. Cables
costing 10 times as much won't improve your Counterpoint as much as
this tube will. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) ADDED 19 November 2005 |
0 |
$135 |
AAAA
(excellent) |
C7 |
Best 6CA4 ever. Extremely good, possessing all the attributes of the C6 but with a smidge more presence and
3-D imaging, and a little less sibilance than the B4 variety. EXCELLENT. (Can be used in all Counterpoint gear that uses 6CA4 rectifier tube without modification.) ADDED 12.18.05 |
10
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$70 |
C6 |
WAS best-sounding 6CA4 ever until C7 came along. Great
balance and space, detailed, full bass. Good breath/body balance, very
3-D. EXCELLENT. (Can be used in all Counterpoint gear that uses 6CA4 rectifier tube without modification.) ADDED 12.3.05, courtesy Steve Durso who found this gem. |
0 |
B5 |
An
outstanding 6BW4 variety. Very articulate, more relaxed-sounding and
less sibilance than B4 variety. Lacks only a teeny bit of presence to
be as good, or better, than the C6.EXCELLENT. Note: "B"-type rectifiers (6BW4) cannot be used in
Counterpoint gear without first re-wiring tube socket. ADDED 12.18.05 |
2
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B4 |
6BW4,Very similar to C6, above.EXCELLENT. Note: "B"-type rectifiers (6BW4) cannot be used in
Counterpoint gear without first re-wiring tube socket. |
1 |
AAA
(very good) |
V14 |
6V4. Very like B1 (below) but with noticeably heftier bass. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) ADDED 12.3.05 |
16 |
$60 |
B1 |
6BW4, Buttery,
warm, natural-sounding. VERY GOOD. Note: "B"-type rectifiers (6BW4)
cannot be used in Counterpoint gear without first re-wiring tube socket. |
10 |
V9 |
These
four 6V4-type rectifiers all sound pretty much alike. A little more
mechanical than the B1, but less top-end edge than the B2. VERY GOOD. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) ADDED 11.19.05 |
0 |
V12 |
0 |
V7 |
0 |
V13
Branded as "Groove Tube" |
0 |
B2 |
6BW4, Sounds like
B4 type, but not as full or smooth. VERY GOOD. Note: "B"-type rectifiers (6BW4) cannot be used
in Counterpoint gear without first re-wiring tube socket. |
8 |
V6 |
6V4, Warm,
involving sound with nice detail. VERY GOOD. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) |
2 |
V1 |
6V4, Involving
sound with nice detail. VERY GOOD. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) |
0 |
V3 |
6V4, Sweeter,
relaxed, more organic than V4. VERY GOOD. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) |
7 |
AA
(good) |
V4 |
6V4, Very similar
to V2 but slightly teeny bit sweeter. Has drive, detail. GOOD, (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) |
1 |
$40 |
C5 |
6CA4, round holes
in micas. Very fast, detailed highs with no shrillness or hash.
Excellent depth. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) |
0 |
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6V4, Very lively,
forward sound, quite dynamic. Prominent upper mids, taut bass.
Loud-sounding, punchy tube. GOOD. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) |
0 |
V5 |
6V4, Not as
forward-sounding as V2, a little nasal-sounding. GOOD. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) |
0 |
V10 |
6V4, A little more mechanical-sounding than the V5.. GOOD. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) |
0 |
C4 |
6CA4, black
background, sweet-sounding. GOOD. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) |
7 |
A
(okay) |
C2 |
6CA4,
Airier-sounding than B3. OKAY. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) |
2 |
$35 |
B3 |
6BW4, sounds like
B1 but with added hash, not was warm as B4. Least good-sounding version
of 6BW4. OKAY. Note: "B"-type rectifiers (6BW4) cannot be used in
Counterpoint gear without first re-wiring tube socket. |
4 |
no grade
("it works") |
V11 |
6V4, Fairly edgy and grainy. According to some sources, this version MAY be the Telefunken EZ80. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) |
0 |
$18 |
C1 |
6CA4,
slow-sounding, boring and confusing. Not much drive, airy but hashy. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) |
2 |
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6CA4, "GE" (this
one we can positively identify by the distinctive acid-etched GE date-code dots). Prominent
upper-mids, hashy-sounding. Worst-sounding 6CA4 ever. (Can be used in all Counterpoint gear that use 6CA4 rectifiers without product modification.) ADDED 11.19.05 |
2 |
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| *Note: "C"
refers to 6CA4/EZ81 types, "V" refers to 6V4/EZ80 types, and "B" refers
to 6BW4 types. |
6LF6 Tubes. This tube, used in the
output stage of the SA-4, are no longer available in matched octets.
Some modification of the SA-4 circuitry is necessary to allow unmatched
tubes to be used. Information about this modification for
do-it-yourselfers is viewable here, or if
you want us to do it, see the SA-4 Upgrades Page
. We don't stock the tube, but you can find GE 6LF6's at www.tubesandmore.com as well
as other online tube vendors.
6SN7 Types. I can provide
tested Sovtek 6SN7's for your SA-11, and later models of the NP220 and
NP100 for $22
each. Equivalent tubes that will certainly work in the NP amps and may
work in the SA-11 (the unmodified SA-11 is very sensitive to any grid
leakage) are: 6SN7GT, 6SN7GTA, 6SN7GTB, 6SN7WGT, 6SN7WGTA, ECC32 (but
not if the tube is light-bulb-shaped: that's a relabled CV-181 and is
not a good equivalent), 5692, 6180, VT-231 (the amazingly
great-sounding WWII military version of the 6SN7, but good luck finding
a pair!), CV1986, and CV1988.
6SL7 Types. I can provide6SL7 triode tubes for your high-sensitivity NP
amplifiers for $37
each. Equivalent tubes that will work in the NP amplifiers are: 6SL7GT,
6SL7WGT, ECC35, 5691, 6113, 6188, CV1984, CV1985, and the Russian
equivalent type 6N9S (their Cyrillic "N" looks like an "H,"so you may
see it advertised as a "6H9S").
5651.
I have been called several times by people who are
concerned that their 5651 must be failed because it is glowing red hot.
Touch it -- it is cold, cold, cold. This is not a vacuum tube, although
it looks like one. It is filled with neon gas and glows orange during
normal operation. It is the voltage reference for the high-voltage
regulators. This is a very reliable device -- we've only seen one fail
in thirty years.
Other Types. The other tube types
used in Counterpoint gear, like the 12AY7, 6080, 6GC5, 6BQ5, 6JC6A,
5651, 5R4 and 6FS7 are available. E-mail me to inquire about price and availability.
How We Test Our Tubes. (just kidding).
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