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DACT |
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DACT
stepped audio attenuators. Danish Audio ConnecT
manufactures a range of High-End stepped audio
attenuators for Hi-Fi, A/V and Pro-Audio, used by DIY
Audiophiles and audio equipment manufacturers throughout
the world: Both models CT1 and CT2 use a resistor
network built on non-inductive SMD resistors. The SMD
resistors are mounted on a very compact PCB, offering a
very short and �pure� signal path. All switch contacts
and connectors are gold plated. |
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The
CT2 Audio Volume Controls are high quality stepped
24-position attenuators. Designed for maximum sonic
quality, accuracy and reliability. This makes them
equally suited for audiophile and professional
applications. Available as master volume control with
60dB attenuation range (1, 2, 4, 6, 8 decks) and as
individual channel fine adjustment (CT2-10k-1/fine) with
0.5dB level change between each step (only available
with 1 deck) Their series resistor networks consist
of 23 non-inductive, low noise, SMD metal film
resistors. The layout of the PC Boards and the choice
of SMD resistors have reduced the signal path to a
minimum length (typical five times shorter than
conventional stepped attenuator designs with leaded
resistors). The PCB design combined with the special
resistors also account for the very low series
inductance and the very low stray capacitance. The
result is a bandwidth beyond even the most demanding
audiophiles� requirements. There has been special
care taken to ensure the durability of CT2. Therefore,
all contacts and PCB traces are gold plated to prevent
any corrosion. As a result, the CT2s will maintain their
specifications after long time of use even in hot and
humid environments. |
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FEATURES |
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SCHEMATIC |
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- Low
noise, non-inductive, metal film SMD resistor
network
- Compact
design
- Entire
signal path gold plated
- Shorter
signal path than conventional attenuators with leaded
resistors
- Reduced
inductance and stray capacitance
- Improved
sonic quality
- Improved
accuracy - 0.05dB tracking and 0.05dB attenuation
accuracy
- Improved
reliability
- Increased
bandwidth
- Reduced
distortion, less than 0.0001%
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SPECIFICATIONS
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MAXIMUM
RATINGS |
Note |
Parameter |
Conditions/comments |
Value |
Unit |
1 |
Switching
capacity |
(resistive
load) |
2V/2A 24V/0.6A
42V/0.4A |
AC/DC |
1 |
Power
dissipation |
(each
resistor) |
100 |
mW |
1 |
Operating ambient temp.
range |
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-25 to +70 (-13 to
+158) |
deg. C (deg.
F) |
1 |
Storage temperature
range |
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-40 to +85 (-40 to
185) |
deg. C (deg.
F) |
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MECHANICAL
CHARACTERISTICS |
Note |
Parameter |
Conditions/comments |
Value |
Unit |
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Number of
positions |
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24 |
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Indexing
angle |
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15 |
deg. |
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Switching
function |
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shorting |
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Gold plating,
contacts |
(hard-gold) |
3 |
μm |
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Gold plating,
wiper |
(hard-gold) |
8 |
μm |
2 |
Mechanical
life |
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>25,000 |
cycles |
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Switching
torque |
1-, 2-, and 4-decks
versions 6- and 8-decks versions |
1.5 3.5 |
Ncm Ncm |
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Nut tightening
torque |
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max. 300 |
Ncm |
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DC ELECTRICAL
CHARACTERISTICS |
Note |
Parameter |
Conditions/comments |
Value |
Unit |
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Total resistance
range |
(standard versions of
CT2) |
10, 20, 50, 100, 250,
500 |
kOhm |
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(fine-adjustment
version) |
10 |
kOhm |
3 |
Total resistance
accuracy |
(new) |
0.1 |
% |
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Attenuation steps,
standard version |
(source output impedance =
0), (load input impedance =
infinite) |
0, 2, 4, 6, 8, 10, 12,
14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34,
38, 42, 46, 50, 60, infinite |
dB |
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Attenuation steps, version
for fine- adjustment |
(source output impedance =
0), (load input impedance =
infinite) |
0, 0.5, 1, 1.5, 2, 2.5,
3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8,
8.5, 9, 9.5, 10, 10.5, 11, 12,
infinite |
dB |
3 |
Attenuation
accuracy |
(new) |
+/- 0.05 |
dB |
3 |
Matching accuracy
(tracking) |
(between two
decks) |
+/- 0.05 |
dB |
4 |
Contact
resistance |
(new) |
max. 0.01 |
Ohm |
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Contact
capacitance |
(adjacent
contacts) |
1 |
pF |
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Series
inductance |
(10 kOhm, input to
ground) |
max. 0.4 |
μH |
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AC ELECTRICAL
CHARACTERISTICS |
Note |
Parameter |
Conditions/comments |
Value |
Unit |
4 |
-3dB
bandwidth |
(10k, A =
-6dB) |
50 |
MHz |
5 |
Noise
voltage |
(10k, input to ground
pin) |
12.8 |
nV/Hz |
6 |
Total
harmonic distortion |
(A = -6dB, fo =
1kHz) |
max. 0.0001 |
% |
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Notes |
1 |
Exposure
to maximum rating conditions for extended periods
of time may affect device
reliability |
2 |
One
cycle is defined as a full rotation from one end
stop to the other and return |
3 |
Typical
values at +25 deg. C ambient temperature. Output
(pin 2) unloaded |
4 |
Measuring
probe input capacitance 1 pF |
5 |
Theoretical
value for an ideal 10k resistor |
6 |
Measured
with Panasonic Audio Analyzer
VP-7722P | |
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To the top
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To the top
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OUTLINE
DRAWING |
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To the top
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NOMINAL
DIMENSIONS Dimensions
common for all models |
Dim. |
Description |
Number |
D1 |
Shaft
diameter |
6.0mm (0.236�) |
D2 |
Shaft length |
14.5mm (0.57�) |
D3 |
Nut
thickness |
2.5mm (0.10�) |
D4 |
Thread
length |
9.5mm (0.37�) |
D5 |
Distance |
2.5mm (0.10�) |
D6 |
Distance |
25mm
(0.98�) |
D7 |
Distance to
terminals |
13.2mm (0.52�) |
D8 |
Distance 1 between
terminals |
14.7mm (0.58�) |
D9 |
Distance 2 between
terminals |
20.2mm (0.80�) |
D10 |
Orientation pin
width |
2.5mm (0.10�) |
D11 |
Orientation pin
height |
1.3mm (0.05�) |
D12 |
Distance between terminal
pins |
2.54mm (0.1�) |
D13 |
Terminal pin
width |
0.64mm (0.025�) |
D14 |
PCB bottom
width |
8.7mm (0.34�) |
D15 |
Total height when mounted
in PCB |
36.5mm (1.44�) |
D16 |
Maximum
width |
25mm (0.98�) |
D17 |
Terminal distance to
PCB |
6.0mm (0.24�) |
D18 |
Terminal pin
thickness |
0.64mm (0.025�) |
D19 |
Terminal pin length below
PCB |
3.5mm (0.14�) |
D20 |
Distance from PCB bottom
to shaft center |
19.9mm (0.783�) |
D21 |
Thread type |
M10
x 0.75 | |
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CONNECTIONS |
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To the top
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ORDERING
INFORMATION |
Part
number |
Description |
CT2-10k-1/fine |
1-channel stepped
attenuator, fine adjustment (0.5dB
steps) |
CT2-xxxk-1 |
1-channel stepped audio
attenuate (mono) |
CT2-xxxk-2 |
2-channel stepped audio
attenuate (stereo) |
CT2-xxxk-4 |
4-channel stepped audio
attenuate (balanced stereo) |
CT2-xxxk-6 |
6-channel stepped audio
attenuate (AV audio) |
CT2-xxxk-8 |
8-channel stepped audio
attenuate (AV audio) |
xxx refers to the
attenuator resistance. Available resistances are
010 (10kOhm), 020 (20kOhm), 050 (50kOhm), 100kOhm,
250kOhm, 500kOhm | |
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