Aikido Stereo 9-Pin PCB
Revision C
USER GUIDE
Introduction
Overview
Schematics
Recommended Configurations
Tube Lists
Assembly Instructions
05/29/2008
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AUDIO DESIGN
Copyright 2006-2008© All Rights Reserved
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voltage power supply; thus, a real shock hazard exists.
Once the power supply is attached, be cautious at all times. In fact, always assume
is
disconnected or shut down. If you are not an experienced electrical practitioner,
plus voltage have someone who is experienced review your
loving solder slingers left; we cannot afford to lose any
4
PCB is extra thick, 0.094 inches (inserting and pulling tubes from their sockets won’t
per traces, and
stage amplifiers;
thus, one board is all that is needed for stereo unbalanced use or one board for one
s, with
eight mounting holes, which help to prevent excessive PCB bending while inserting
spaced solder pads
foil
film resistors, for example). In addition, most capacitor
sized coupling
The boards hold two coupling capacitors, each finding
its own 1M resistor to ground. Why? The idea here is that you can select (via a rotary
citors in parallel. Why again? One coupling
slug
tantalum…. As they used to sing in a candy bar commercial: “Sometimes you feel like
capacitor has its virtues and failings. So use the one that best suits the
music; for example, one type of coupling capacitors for old Frank Sinatra recordings
valued capacitor would set
frequency cutoff of 80Hz for background or late night listening; the other
could
be hardwired together on the PCBs via jumpers J8 and J9, one smaller one acting as a
This PCB is for use with a high-
that capacitors will have retained their charge even after the power supply
before applying the Bwork. There are too few tubemore.
A
Warning!
@
Rev. C Overview
Thank you for your purchase of the TCJ Aikido 9-pin stereo Rev. C PCB. This FR-
bend or break this board), double-sided, with plated-through 2oz cop
the boards are made in the USA. Each PCB holds two Aikido line-
channel of balanced amplification. The boards are four inches by ten inche
and pulling tubes from their sockets.
PCB Features
Redundant Solder Pads This board holds two sets of differentlyfor each critical resistor, so that radial and axial resistors can easily be used (bulkresistors and carbonlocations find many redundant solder pads, so wildly differingcapacitors can be placed neatly on the board, without excessively bending their leads.
Dual Coupling Capacitors
switch) between C1 or C2 or both capa
capacitor can be Teflon and the other oil or polypropylene or bee’s wax or wet-
a nut; sometimes you don't.”
Each type of
and the other for Beethoven string quartets.
Or the same flavor capacitor can fill both spots: one lowera lowhigher-valued capacitor, 5Hz for full range listening.
Or if you have found the perfect type of coupling capacitor, the two capacitors
bypass capacitor for the lager coupling capacitor.
2
amplifier delivers the sonic goods. It offers low distortion, low output
s
lies in its internal symmetry,
whic
circuit works
by
resistor,
, complementary, balancing
f the eyes were
perfect, then perfectly flat (perfectly linear) lenses would be needed, whereas imperfect
loading a
age and idle current
works well to flatten the transfer curve out of the
Although they
would never fit on the printed circuit board (PCBs), 211 and 845 triodes could be used
or any other
, not the tubes that make the Aikido
any believe that a different triode equals a different topology; it
f being a
The Aikido circuit sidesteps power supply noise by incorporating the noise into its
normal operation. The improved PSRR advantage is important, for it greatly unburdens
king or tube selecting, you should easily be able to get a
cathode amplifier with the same tubes
6dB PSRR); with some tweaking of resistor R15’s value,
ditionally, unless regulated power supplies are used for
the plate and heater, these critical voltages will vary at the whim of the power company
and your house’s and neighbors’ house’s use, usually throwing the once fixed voltage
rtheless, the Aikido amplifier will still function flawlessly, as it
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Introduction to the Aikido
The Aikido
impedance, a great PSRR figure, and feedback-free amplification. The secret to it
superb performance— in spite not using global feedback—
h balances imperfections with imperfections. As a result, the Aikido
at least a magnitude better than the equivalent SRPP or grounded-cathode amplifier.
For example, the Aikido circuit produces far less distortion than comparable circuits
using the triode’s own nonlinearity against itself. The triode is not as linear as a
so ideally, it should not see a linear load, but a corresponding
non-linear load. An analogy is found in someone needing eyeglasses; i
eyes need counterbalancing lenses (non-linear lenses) to see straight. Now,
triode with the same triode— under the same cathode-to-plate volt
and with the same cathode resistor—
amplifier.
B+
C
6922 6922
Rk
in
Rgs
Rg
Rk
Rgs
Rk
R15
out
69226922
Rk
R16
Aikido Amplifier
In the schematic above, the triodes are so specified for example only.
to make an Aikido amplifier. The circuit does not rely on 6922 triodes
specific triodes to work correctly. It’s the topology
special. (Far too m
doesn't. Making this mistake would be like thinking that the essential aspect o
seeing- eye dog rested in being a Golden Lab.)
the power-supply. With no twea
-30dB PSRR figure (a conventional groundedand current draw yields only a -
-60dB or more is possible. Ad
relationships askew. Neve
tracks these voltage changes symmetrically.
they
wear out. Just as a tire’s weight and diameter decrease over time, so too the tube’s
conductance. So the fresh 6DJ8 is not the same as that same 6DJ8 after 2,000 hours of
which they are inclined to do,
—
the Aikido amplifier will always bias up correctly, splitting the B+ voltage between the
triodes. Moreover, the Aikido amplifier does not make huge popping swings at start
up, as the output does not start at the B+ and then swing down a hundred or so volts
when the tube heats up, as it does in a ground
supply noise from the output, by injecting the same
tube cathode follower circuit.
The way it works is that the input stage (the first two triodes) define a voltage divider
the PS noise is presented to the CF's grid; at the same time the
100k resistors also define a voltage divider of 50%, so the bottom triode's grid also
sees 50% of the PS noise. Since both of these signals are equal in amplitude and phase,
other out, as each triodes sees an identical increase in plate current
If the output connection is taken from the output cathode follower's cathode, then the
true if the cathode follower's cathode resistor
is removed. (Besides, this resistor actually makes for a better sounding cathode
follower, as it linearizes the cathode follower at the expense of a higher output
should
ohms for example. When used
o cathode resistor bypass capacitors should be used, as these
y few do not damage the sound,
How do I wire up a rotary switch for switching between the two coupling
position switch and some hookup wire. All
four coupling capacitors attach to the input contacts and the two channels of output
coupling capacitors C1’s or C2’s or both capacitors’ outputs. The
drawing below shows the knob on the faceplate and the rotary switch from behind.
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Remember, tubes are not yardsticks that never change, being more like car tires—
use. But as long as the two triodes age in the same way—
as they do the same amount of work and share the same materials and environment
-cathode amplifier.
This circuit eliminates poweramount of PS noise at the top and bottom of the two-
of 50%, so that 50% of
they cancel each
(imagine two equally strong men in a tug of war contest).
3
balance will be broken. The same holds
impedance. Unfortunately, it should be removed and the bypass capacitor C3
be used when driving low- impedance headphones, 32as a line stage amplifier, n
capacitors are very much in the signal path and ver
unless high quality capacitors are used.)
capacitors? We need a four- pole, three-
can receive either
(The switch is shown on the "C1 + C2" position.)
Right Output
C1
C2
Lt C2
Lt C1
Rt C1
Switch Rear
Rt C2
C1 & C2
Switch Front
Left Output
4
The board assumes that a DC 12V power supply will be used for the heaters, so that
6.3V heater tubes (like the 6FQ7 and 6DJ8) or 12.6V tubes (like the 12AU7 or 12AX7)
mple 6GC7
for the input tube and a 12BH7 for the output tube. For example, if the input tube (V2
and V3) is a 12AX7 and the output tube is a 6H30 (V1 and V4), then use jumpers J1, J5
a 6V heater
power supply can be used with the PCB, as long as all the tubes used have 6.3V heaters
(or 5V or 8V or 18V power supply can be used, if all the tubes share the same 5V or 8V
tly good tubes with
uncommon heater voltages can often be found at swap meets, eBay, and surplus stores
A 25V heater power supply can be
are listed on the
is a 12AX7 and the output
AC Heaters
V) can be used, if the heater
citors C7, C8, C9, C10 are left off the board, or are replaced by 0.01µF
cathode voltage experienced differs
between triodes. The safest path is to reference the heater power supply to a voltage
ly.
The ¼ B+ voltage ensures that both top and bottom triodes see the same magnitude of
cathode voltage. The easiest way to set this voltage relationship up is the
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Heater Issues
can be used. Both types can be used exclusively, or simultaneously; for exa
and J6.
6V Heater Power Supply Although designed for a 12V power supply,
or 18V heater voltage). Just use jumpers J1 and J4 only. Note: Perfec
for a few dollars each. Think outside 6.3V box. (
used, if only 12.6V tubes are used. Just use the jumper settings that
PCB for 6V use. For example, if the input tube [V2 and V3]
tube is a 12AU7 [V1 and V4], then use jumpers J1 and J4. )
An AC heater power supply (6.3V or 12.6
shunting capa
ceramic capacitors.
Filament Jumper Wire Schedule
J1 J2
V1
5
4
C7
With a 6.3V PS
Use J2, J3, J5, and J6 only
and all tubes must be
6.3V types.
Do not use capacitors, C7, C8, C9, or C10 with an AC heater PS
V2
5
C8
-H
J5
4
+H
J6
4
J4
With a 12.6V PS
Output Tubes V1 and V4:
If tubes are 6V, use J1 only.
If tubes are 12V, use J2 and J3 only.
Input Tubes V2 and V3:
If tubes are 6V, use J4 only.
If tubes are 12V, use J5 and J6 only.
V3
C9
5
5
V4
C10
J3
4
Since one triode stands atop another, the heater-to-
equal to one fourth the B+ voltage; for example, 75V, when using a 300V power supp
heater-tofollowing circuit:
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Alternatively, you might experiment with floating the
heater power supply, by “grounding” the heater power
supply via only a 0.1µF film or ceramic capacitor. The
capacitor will charge up through the leakage current
this method
The power supply is external to the Aikido PCB and can be mounted in, or outside,
the chassis that houses the PCB. The optimal power supply voltage depends on the
tubes used. For example, 6GM8s (ECC86) can be used with a low 24V power supply,
while 6FQ7s work better with a 250
the limit here,
The genius of the Aikido circuit is found in both its low distortion and great PSRR
eless, a good power supply helps (there is a practical limit to how large a
diode rectified power supply. If you insist on going the cheap
y the circuit below, as it yields a lot of performance for little money. FRED
5
100
100
DC
Heater
PS
0.1µF
250V
B+
4
B+
300k
2W
AC
B+
4
100k
1/2W
0.1µF
250V
between heater and cathodes. Not only is
cheap, it is often quite effective in reducing hum.
Power Supply
B+
300k
2W
B+
4
100k
1/2W
-300V B-plus voltage. The sky is not
as the heater-to-cathode voltage sets an upward limit of about 400V.
figure. Noneth
power-supply noise signal can be nulled). I recommend you use at least a solid, chokefiltered tube or fastroute, tr
rectifiers are expensive, but make an excellent upgrade to the lowly 1N4007.
.01µF
1KV
.01µF
1KV
.01µF
1KV
100mA
high-DCR
.01µF
1KV
All Diodes = 1N4007
All Resistors = 1 ohm 1/2W
6
Jumper J7 connects the PCB’s ground to the chassis through the top centermost
mounting hole. If you wish to float the chassis or capacitor couple the chassis to ground,
valued capacitor (0.01 to
rings are used with PCB standoffs, then the ground
he Aikido amplifier defines a new topology without fixed
old topology with specified part choices. In other words, an Aikido
amplifier can be built in a nearly infinite number of ways. For example, a 12AX7 input
tube will yield a gain close to 50 (mu/2), which would be suitable for a phono preamp or
ier’s input stage; a 6FQ7 (6CG7) input tube will yield a gain near 10, which
would be excellent for a line stage amplifier; the 6DJ8 or 6H30 in the output stage
would deliver a low output impedance that could drive capacitance
laden cables or even
edance headphones. In other words, the list of possible tubes is a long one:
, 6DJ8, 6FQ7, 6GC7, 6H30, 6KN8, 6N1P, 12AT7,
12AU7, 12AV7, 12AX7, 12BH7, 12DJ8, 12FQ7, 5751, 5963, 5965, 6072, 6922,
pulations are that the two triodes within the
out. Sadly, the
does with the 6CG7 and 6DJ8,
, which will ground the
d allow
The cathode resistor sets the idle current for the triode: the larger the value of the
value cathode resistors
1k). I recommend
; or put differently, run the input
Interestingly enough, a lower idle current for the
es not seem to incur the same large increase in distortion that one would
expect in other topologies (a testament to the Aikido’s principle of symmetrical loading).
ohm resistors
6CG7s throughout. Thus, the
output tubes will age more quickly than the input tubes, so rotating output for input
e’s cathode resistor to be bypassed, when
headphones, as it provides the lowest
If used, C3 should be at least a
capacitance cable is to be driven, use a
higher idle current and retain the cathode resistor, R8, and leave capacitor C3 off.
then either leave jumper J7 out or replace it with a small-
0.1µF). Warning: if rubber Oconnection to the chassis is not likely to be made.
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Tube Selection
Unlike 99.9% of tube circuits, t
part choices, not an
a SE amplif
high-imp
6AQ8, 6BC8, 6BK7, 6BQ7, 6BS8
E188CC, ECC88, ECC99… The only sti
envelope be similar and that the tube conforms to the 9A or 9AJ base pin12B4 and 5687 cannot be used with this PCB.
Internal Shields
If the triode’s pin 9 attaches to an internal shield, as it
then capacitors, C11 and C12 can be replaced with a jumper
shield. However, using the capacitors will also ground the shield (in AC terms) an
using triodes whose pin-9 attaches to the center tap of its heater, such as the 12AU7.
Cathode Resistor Values
resistor, the less current. In general, high-mu triodes require high(1-2K) and low-mu triodes require low-valued cathode resistors (100running the output tubes hotter than the input tubes
tubes cooler than the output tubes.
input stage do
For example, 1k cathode resistors for the input tube (V2 and V3) and 300for the output tubes (V1 and V4), when using 6FQ7s or
tubes can extend the useful life of the tubes.
Capacitor C3 allows the bottom output triod
resistor R8 is replaced with a jumper wire; this arrangement is useful when driving lowimpedance loads, such as 300- ohm or 32-ohm
possible output impedance from the Aikido amplifier.
1kµF capacitor. On the other hand, if high-
Current is more important than the lowest possible output impedance.
perfect line amplifier, as it offers low distortion, low
all without a global
. For guidance on part
values, look at the page
amplifier design examples.
For example,
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Configuring the PCB as a Line Amplifier
The Aikido topology makes a
output impedance, and excellent power-supply noise rejection—
feedback loop. The key points are not to use capacitor C3
12, which lists several lineCalculating R15’s value is easy; it equals R16 against [(mu -2)/(mu + 2)].
a triode with a mu of 20 results in R15 = 100k x (20 – 2)/(20 + 2) = 81.8k (82k)
B+
R4
in
R3
C11
R1
R2
(input) V2, V3 (output) V1, V4
Typical Part Values
B+ Voltage =
Heater Voltage =
R1,5,6,7,12,13,14 =
R2,4 =
R3,9,10 =
R8,11 =
R15 =
R16 =
R6
C6C5
R7
R9
C1 out
R8
C2
J8 (J9)
out
R15
R10
C12
R5
() Parentheses denote recommended values
R11
C3
R16R12 R13 R14
6CG7 & 6DJ8 6CG7 & 6CG7 12AU7 & 12AU7 12AU7 & 12BH7
170V - 250V (200V) 200V - 300V (300V) 200V - 300V (250V) 200V - 300V (300V)
6.3V 6.3V 12.6V 12.6V
1M 1M 1M 1M
270 - 1k (470)* 470 - 2k (870)* 470 - 2k (680)* 470 - 2k (1k)*
100 - 1k (300)* Same Same Same
200 - 330 (200 10mA)* 270 - 680 (270)* 180 - 470 (200)* 200 - 470 (523)*
87.5k 83.2k 80k 79.3k
100k Same Same Same
*High-quality resistors essential in this position
All resistors 1/2W or higher
C1 =
0.1 - 4µF* Film Same Same Same
C2 =
0.1 - 4µF* Oil " " "
C3 =
none " " "
C5 =
1 - 10µF* Film or Oil " " "
C6 =
C7,8,9,10 =
C11,12 =
(input) V2, V3 =
(output) V1, V4=
0.1 - 1µF* Film or Oil " " "
47µF - 1kµF, 16V " " "
0.1µF 160V(optional) Same None None
*Voltage rating must equal or exceed B+ voltage
6CG7, 6FQ7 6CG7, 6FQ7 12AU7, 5814, 5963, 12AU7, 5814, 5963,
6189, ECC82 6189, ECC82
6DJ8, 6922, 6CG7, 6FQ7 12AU7, 5814, ECC82 12BH7, ECC99
7308, E88CC
8
High transconductance output tubes are best for driving headphones, for example, the
ECC99. A coupling capacitor of at least 33µF is required
when driving 300
quality,
can be bypassed by placing
ended affair, nothing pulls while something
ended mode is sonically, it cannot
AB output stages can
For a line stage, such big voltage and current swings
are seldom required; headphones, on the other hand, do demand a lot more power;
a
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Configuring the PCB as a Headphone Amplifier
The standard Aikido is a thoroughly singleelse pushes. Unfortunately, wonderful as singleprovide the larger voltage and current swings that a push-pull output stage can. Singleended stages can only deliver up to the idle current into a load, whereas class-A pushpull stages can deliver up to twice the idle current; and classdeliver many times the idle current.
really, a 32-ohm load is brutally low impedance for any tube to drive. Unfortunately,
heavy idle current is needed to ensure large voltage swings into low-impedance loads.
B+
C5
R6
C6
R7
R4
in
R3
R1 C11 R5
R2
R9
C12
R8
R11
R10
C3
C1 out
C2
6DJ8, 6H30, 12BH7, and
-ohm headphones; 330µF for 32- ohm headphones. Use a highsmall-valued bypass capacitor in C2’s position. Capacitor C3
a small film capacitor across the leads of resistor R11.
Right HP
output
Left Line Output
J8 (& J9)
R14
R15
R16R12 R13
Line
Mute
Headphones
Lt C2
Rt C1
Lt C1
Rt C2
Switch Front
Right Line Output
Left HP
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Before soldering, be sure to clean both sides of the PCB with 90% isopropyl alcohol,
wiping away all fingerprints. First, solder the shortest parts (usually the resistors) in
re that both the
solder and the part leads are shiny and not dull gray. Steel wool can restore luster and
plated leads, remove
of gold will poison a
solder joint, making it brittle; use sandpaper, steel wool, or a solder pot. NASA forbids
contaminated solder joints; you should as well. (Yes, there are many quality
Normally, such as when the PCB sits on the floor of its chassis, all the parts sit on the
top side of the PCB (the top side is marked). If you wish to have the tubes protrude
hin 1" of the top panel
with the aid of standoffs), then all the other parts
can be
sided board after all (be sure to observe
avy coupling capacitors to
If you would like to see some new audio PCB or kit or recommend a change to an
existing product or if you need help figuring out the heater jumper settings or cathode
mail to the address above (begin the subject line
with either “Aikido” or “tube”).
9
Typical Part Values
B+ Voltage =
Heater Voltage =
R1,5,6,7,12,13 =
R2,4 =
R3,9,10 =
R8,11 =
R15 =
R16 =
C1 =
C2 =
C3 =
C5 =
C6 =
C7,8,9,10 =
C11,12 =
(input) V2, V3 =
(output) V1, V4 =
() Parentheses denote recommended values
6CG7 & 6DJ8 6CG7 & 6CG7 12AU7 & 6H30
170V - 250V (250V) 200V - 300V (300V) 200V - 300V (150V)
6.3V or 12.6V 6.3V or 12.6V 12.6V
1M 1M 1M
270 - 1k (640 5mA)* 470 - 2k (640 5mA)* 470 - 2k (741 3mA)*
100 - 1k (300)* 100 - 1k (300)* 100 - 1k (300)*
200 - 330 (291 10mA)* 200 - 470 (240 10mA)* 200 - 470 (74 30mA)*
87.3k 83.2k 76.5k
100k 100k 100k
*High-quality resistors essential in this position
All resistors 1/2W or higher
47µF* Film for 300-ohm HP Same Same
470µF* for 32-ohm HP Not recommended 470µF* for 32-ohm HP
0.47µF* Film or oil Same Same
10 - 1kµF, 10V Electrolytic "10 - 1kµF, 16V Electrolytic
1 - 10µF* " "
0.047µF - 1µF* Film or oil " "
10µF-1kµF, 16V Electrolytic " Same
0.1µF 160V(optional) " None
*voltage rating must equal or exceed B+ voltage
6CG7, 6FQ7 6CG7, 6FQ7 12AU7, 5814, 5963,
6189, ECC82
6DJ8, 6922, 6CG7, 6FQ7 6H30
7308, ECC88
Assembly
place, then the next tallest parts, and then the next tallest... Make su
sheen by rubbing off oxidation. If some of the parts have goldthe gold flash before soldering the part, as only a few molecules
any goldparts with gold- flashed leads, but the use of gold is a marketing gimmick.)
from holes on the top of the chassis (and to place the PCB wit
— except the tube sockets—
placed on the PCB’s backside; it is a doublethe electrolytic capacitors' polarity and glue or tie-wrap he
the PCB).
Let me know what you think
resistor values, drop me a line by e-
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in
7
6
8
R3
2
1
V2
R1
C11R2R5
9
3
R6
R9
2
1
V1
6
3
R8 R4
7
R7
C12
9
R11
8
C3C3
R12
R13
C1
C2
R14
(Rev. C)
J7
B+
C6
R15
out out
out
out
R16
R14
R13
C1
J8 J8
C2
R12
C5
R7
R10 R10
2
3
8
6
7
1
R8
V4
R11
9
C12
9-Pin Aikido Schematic
R9
R6
3
R4
6
8
R2
1
7
2
V3
R3
9
in
R1 C11 R5
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11
1.60"1.60" 2.30"2.30"
0.85"
.25"
46
5
5
19
V4
7 3
8 2
28
37
V3
6 4
9 1
OVERALL PC BOARD DIMENSIONS: 4.00" x 10.0"8 MOUNTING HOLE LOCATIONS
4 VACUUM TUBE LOCATIONS
.125R, 4 PLCS
.25"
.50"
46
5
19
V2
7 3
8 2
Top Side PCB Mechanical Layout
28
37
5
V1
6 4
9 1
1.00"
2.00"
2.00" 2.75" 2.75" 2.00"
.25"
12
based Aikido amplifier PCB. The table lists the same
tube under different B+ voltages and with different cathode resistor values. Two gains are listed: the first is
input position in the Aikido; the second is the gain of the same tube in the
To calculate the final gain multiply the two voltage gains together (or add the gain in dBs
e of 300V, and a 6CG7 input tube
with cathode resistors of 1k, and a 6DJ8 output tube with cathode resistors of 481 ohms, the final voltage
gain equals 10.1 from the 6CG7 against the 0.96 gain of the 6DJ8, with a product of 9.7. or, working with dB
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Tube B+ Ik(mA) mu rp Rk R15 R16 R17
6AQ8 300V 10.0 57.0 9700 100 93.2k 100k 170 28.1 29.0 0.97 -0.24 248 85
6BK7 300V 10.0 43.0 4600 200 91.1k 100k 107 21.2 26.5 0.97 -0.27 279 53
6BQ7 300V 10.0 38.0 5900 191 90.0k 100k 155 18.7 25.5 0.96 -0.32 311 78
6BS8 300V 10.0 36.0 5000 220 89.5k 100k 139 17.8 25.0 0.96 -0.33 321 69
6CG7 150V 3.0 20.5 10200 583 82.2k 100k 498 10.0 20.0 0.93 -0.59 827 249
6CG7 200V 5.0 21.1 8960 397 82.7k 100k 425 10.4 20.3 0.93 -0.59 657 212
6CG7 250V 5.0 21.0 9250 626 82.6k 100k 440 10.3 20.2 0.94 -0.56 820 220
6CG7 300V 4.5 20.8 9840 1000 82.5k 100k 473 10.1 20.1 0.94 -0.53 1063 237
6CG7 300V 7.3 21.4 8370 470 82.9k 100k 391 10.5 20.4 0.94 -0.56 686 196
6CG7 300V 10.0 21.9 7530 243 83.3k 100k 344 10.8 20.7 0.93 -0.60 489 172
6CG7 350V 10.0 21.8 7680 352 83.2k 100k 352 10.7 20.6 0.94 -0.57 576 176
6DJ8 100V 5.0 30.2 3670 182 87.6k 100k 122 15.0 23.5 0.96 -0.39 273 61
6DJ8 150V 10.0 30.7 2870 124 87.8k 100k 93 15.2 23.7 0.96 -0.39 199 47
6DJ8 200V 10.0 30.0 2960 205 87.5k 100k 99 14.9 23.4 0.96 -0.37 274 49
6DJ8 250V 10.0 29.6 3060 291 87.3k 100k 103 14.6 23.3 0.96 -0.36 350 52
6DJ8 250V 5.0 28.6 3980 673 86.9k 100k 139 14.0 22.9 0.96 -0.35 667 70
6DJ8 300V 5.0 28.3 4080 845 86.8k 100k 144 13.8 22.8 0.96 -0.34 787 72
6DJ8 300V 8.0 28.9 3400 481 87.1k 100k 118 14.2 23.0 0.96 -0.35 511 59
6FQ7
See 6CG7 and 6SN7
6GM8 24V 2.0 14.0 3400 187 75.0k 100k 243 7.0 16.8 0.90 -0.90 357 121
6H30 100V 20.0 15.4 1140 69 77.0k 100k 74 7.7 17.7 0.91 -0.80 127 37
6H30 150V 30.0 15.9 1040 74 77.7k 100k 65 7.9 18.0 0.92 -0.75 124 33
6H30 200V 20.0 15.4 1310 221 77.0k 100k 85 7.7 17.7 0.92 -0.68 267 43
6H30 250V 20.0 15.4 1380 294 77.0k 100k 90 7.7 17.7 0.93 -0.66 330 45
6H30 300V 15.0 15.0 1670 530 76.5k 100k 111 7.4 17.4 0.93 -0.65 528 56
6N1P 200V 3.0 39.8 12200 328 90.4k 100k 307 19.4 25.8 0.96 -0.32 539 153
6N1P 250V 5.0 36.0 9480 221 89.5k 100k 263 17.7 25.0 0.96 -0.36 422 132
6N1P 300V 5.0 35.0 956 642 89.2k 100k 27 17.1 24.7 0.97 -0.25 569 14
6N27P 24V 2.0 14.0 3400 187 75.0k 100k 243 7.0 16.8 0.90 -0.90 357 121
9AQ8
See 6AQ8
12AT7 200V 3.7 60.0 15000 270 93.5k 100k 250 29.1 29.3 0.98 -0.21 457 125
12AU7 100V 2.5 17.0 9560 427 78.9k 100k 562 8.4 18.4 0.92 -0.75 757 281
12AU7 150V 3.0 16.6 9570 741 78.5k 100k 577 8.1 18.2 0.92 -0.71 959 288
12AU7 200V 4.0 16.7 9130 768 78.6k 100k 547 8.2 18.2 0.92 -0.69 959 273
12AU7 250V 8.0 17.9 7440 336 79.9k 100k 416 8.8 18.9 0.92 -0.71 601 208
12AU7 300V 10.0 18.1 7120 328 80.1k 100k 393 8.9 19.0 0.92 -0.70 581 197
12AV7 200V 9.0 37.0 6100 120 89.7k 100k 165 18.3 25.3 0.96 -0.36 258 82
12AV7 300V 18.0 41.0 4800 56 90.7k 117 20.4 26.2 0.96 -0.35 160 59
12AZ7
See 12AT7
12AX7 200V 0.5 100.0 80000 2000 96.1k 100k 800 39.0 31.8 0.99 -0.11 1719 400
12AX7 300V 1.0 100.0 62500 1100 96.1k 100k 625 42.6 32.6 0.99 -0.12 1238 313
12BH7 100V 4.0 16.1 5480 340 77.9k 100k 340 8.0 18.0 0.92 -0.76 549 170
12BH7 150V 4.0 15.7 6090 706 77.4k 100k 388 7.7 17.7 0.92 -0.71 826 194
12BH7 200V 5.0 15.9 6140 787 77.7k 100k 386 7.8 17.8 0.92 -0.68 877 193
12BH7 250V 10.0 17.4 4870 383 79.4k 100k 280 8.6 18.7 0.93 -0.67 541 140
12BH7 300V 15.0 18.4 4300 267 80.4k 100k 234 9.1 19.2 0.93 -0.65 422 117
12BZ7 300V 100.0 31800 96.1k 100k 318 48.5 33.7 0.98 -0.17 292 159
12DJ8
See 6DJ8
12FQ7
See 6SN7
5687 150V 24.0 18.1 1760 37 80.1k 100k 97 9.0 19.1 0.91 -0.78 119 49
5687 200V 20.0 17.5 1970 132 79.5k 100k 113 8.7 18.8 0.92 -0.68 216 56
5687 250V 20.0 17.4 2060 198 79.4k 100k 118 8.7 18.7 0.93 -0.65 276 59
5687 300V 15.0 16.9 2440 397 78.8k 100k 144 8.4 18.5 0.93 -0.62 455 72
5751 200V 0.8 70.0 58000 1250 94.4k 100k 829 30.5 29.7 0.98 -0.17 1407 414
5963 250V 10.0 21.0 6600 200 82.6k 100k 314 10.4 20.3 0.93 -0.63 433 157
5965 300V 8.2 47.0 7250 220 91.8k 100k 154 23.1 27.3 0.97 -0.26 337 77
6072 300V 2.0 44.0 25000 1250 91.3k 100k 568 20.3 26.2 0.97 -0.25 1272 284
7119 300V 15.0 21.7 2390 324 83.1k 100k 110 10.7 20.6 0.95 -0.48 377 55
ECC81
See 12AT7
ECC82
See 12AU7
ECC83
See 12AX7
ECC85
See 6AQ8
ECC86
See 6GM8
Input
Gain
Input
Gain dBs
Output
Gain
Output
in dBs
Zo Line
Amp.
Zo HP
Amp
The table above lists many triodes suitable for the 9-pin-
the gain the tube realizes in the
output stage.
together). For example, given an Aikido line amplifier with a B+ voltag
instead, 20.1dB plus -.35dB, for a total of 19.75dB. (Aren’t decibels great?)
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