stereo – headphone amplifier line signal amplifier lpa-2s lpa-2s + sia-5

stereo – headphone amplifier line signal amplifier lpa-2s lpa-2s + sia-5
STEREO – HEADPHONE AMPLIFIER
LINE SIGNAL AMPLIFIER
LPA-2S
LPA-2S + SIA-5
1. DESCRIPTION:
The LPA-2S is a High-End headphone module for
demanding application in the medium and high
power range, available in various versions. It is
universally applicable, so that practically all headphones with an impendance of 16 Ω... 2 kΩ can be
driven extremely distortion-free. The largest
amount of power, over 2 x 1200 mW, is delivered
by the LPA-2S module, with a headphone impedance between 22..100 Ω. The high current delivery
ability of the fully DC voltage-coupled unit using
the most modern components also allows the parallel connection of several sets of headphones, depending on their impedance.
The low resistance outputs provide an exact damping for the connected headphones.
With its compact construction, this module can be
retroactively built into many devices. The extremely low, flat module unit height (only 16 mm
without poti) means that it can easily be installed
into just 1 section of an existing 19" rack.
sound performance and a high impedance 2 MΩ
stereo input. 10 MΩ impedance for the SIA-5.V2.
For the integration of the SIA-5 board in the LPA2S, jumpers are provided for module adaptation.
The unmatched low noise and the excellent frequency and phase response allow the LPA-2S to
operate additionally as an asymmetrical stereo amplifier with level control for particularly low ohm
loads or long cables. Distribution amplifiers (1 stereo signal via several channels) can be built up easily with cascades of several boards and flat ribbon
cable connection technology.
Because of these features headphone distribution
amplifiers with one stereo input and several outputs for different musicians with in each case individually adjustable volume controls are possible.
The LPA-2S resists short circuits to ground on both
outputs without damaging the unit.
The integrated stereo volume control is in each case a selected ALPS-version with a 70 dB control
range. Available either in the flat version with a
continuously variable volume control, or in a rest
work variant with 41 incremental volume steps, as
well as intermediate positions too. The excellent
synchronisation between both channels is, during
normal working conditions, from -40.. 0 dB less
than typ. 1 dB, and -30.. 0 dB < 0.5 dB in the control range.
The LPA-2S is fastened using a 8 mm drilled hole,
with "Song" potentiometer a 9mm hole for mounting on the front panel. The shaft diameter of the
respective potentiometers is 6 mm.
An additional basic amplification can be enabled by
using jumpers in 3 stages in order to adapt the
headphone sensitivity : +1 dB, +6 dB, +12 dB
ranges (- 6... +18 dB with the SIA-5 board)
Iff an internal power supply is not at hand, suitable
mains adapters (PWS-04B-T, SMPS-14T and SMPS24T.V2) are available.
A special slot permits installation of an optional
new miniature symmetric SIA-5 ore the newest
SIA-5.V2 ultra low noise board to achive excellent
The input signals, output signals and the power
supply are connected via a 14 pole Micro-Match
plug on the board.
The symmetrical power supply is usually provided
by the device to be reequipped, as supply voltages
already often exist within it.
0.3 m of flat ribbon cable and 14 pole plug connector are included in delivery.
2. PIN ASSIGNMENT CN1:
Pin
Pin
Pin
Pin
Pin
Pin
Pin
Pin
Pin
Pin
Pin
Pin
Pin
Pin
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Power supply + 12..19 V
GND Power
Power supply - 12..19 V
Output channel 2, headphones right
Output channel 2, headphones right
Output channel 1, headphones left
Output channel 1, headphones left
GND Output, Headphones
GND Output, Headphones
Input channel 2 - (without SIA-5 → GND)
Input channel 2 +
GND Input
Input channel 1 - (without SIA-5 → GND)
Input channel 1 +
LPA-2 original dimensions
3.0 AUDIO QUALITY:
The extremely low distortion at 1 kHz load with
both channels in simultaneous operation display
similar measurement curves. The steps of the
measuring curve result from the amplifier switchover of the Audio-Analyzers only. The distortion
performance (THD k2..k9) was registered at 1 mW
to 1500 mW at 62 Ω load. The distortion levels for
higher headphone impedances are even lower and
hardly detectable!
The left scale shows the distortion degree in %, the
right scale in "dB" and the lower scale displays the
corresponding output power in mW. The blue
marker shows the total distortion at 2 x 500 mW
with distortion of 0.00007% (-123 dB).
3.1 TECHNICAL DATA:
measured with
+/-19 volts of supply voltage, +6 dBu level and 0 dB gain, if not otherwise declared, without
SIA-5 input board (without symmetrical inputs)
Power supply :
+/- 12...+/- 19 V (max. 1 mV Noise)
Power consumption no-load :
32 mA, with additional SIA-5 : 52mA
Power consumption full power:
230 mA max. at 22 Ω, with additional SIA-5 : 250 mA max. at 22 Ω
Gain :
- 70...0 dB (Incremental poti with 21 steps ore steples, typ. < 1dB matching from - 40..0 dB)
Input impedance :
5 kΩ ... 50 kΩ unbalanced, 2 MΩ with balanced input (SIA-5 integriert)
Input voltage max. :
+23,5 dBu
Output impedance :
< 1.8 Ω
Output voltage max. :
+ 24,0 dBu (with gain > 1 dB)
Dynamic, volume fully clockwise: 139 dB at 300 Ω, 138 dB at 68 Ω, measured with A-weighting filter typ. > 140 dB !!
Distortion + Noise (THD + N) :
20 Hz...22 kHz < 0,0005 % at 2x 500 mW, 33 Ω
THD-Distortion 1 kHz (k2..k9):
< -115 dB at half power, typ < -120 dB
Intermodulation 250/8kHz :
typ. 0,0001 % at 2x 500 mW, 100 Ω load
Frequency response :
0 Hz...22 kHz less than ± 0,01 dB, 0 Hz..100 kHz <± 0,2 dB at 100 Ω
Large signal bandwith:
0 Hz...> 180 kHz at 100 Ω
Slew Rate :
typ. 20 V/µsec
Crosstalk L < > R:
110 dB at 1 kHz 100 dB at 10 kHz
Max. power at THD (k2-k9) < 0,1% :
600 Ω
300 Ω
200 Ω
150 Ω
100 Ω
70 Ω
47 Ω
33 Ω
22 Ω
2x 260 mW
2x 500 mW
2x 730 mW
2x 1000 mW
2x 1300 mW
2x 1650 mW
2x 1500 mW
2x 1450 mW
2x 1200 mW
Output noise
with following gain :
Noise unweighted (20 Hz...22 kHz eff.) :
Noise weighted (A-weighting eff.) :
Noise weighted qp (CCIR 468-4) :
Dimensions :
+ 0 dB
+ 1 dB
+ 6 dB
12 dB
< - 116,0 dBu
< - 119,0 dBu
< - 110,0 dBu
< -116,0 dBu
< -118,5 dBu
< -109,5 dBu
< - 113,5 dBu
< - 116,0 dBu
< - 107,0 dBu
< - 109,0 dBu
< - 111,5 dBu
< - 102,5 dBu
67 x 47 x 28 (25.5) mm (width x depth x height) incl. incremental potentiometer ("Song"-Poti)
FUNK TONSTUDIOTECHNIK GERMANY 10997 BERLIN PFUELSTRASSE 1a 0049 (0)30 38106174 0049 (0)30 6123449
Infos : www.funk-tonstudiotechnik.de
THD over Output Power 2x 1 mW...1500 mW 1 kHz at 2x 62 Ω (LPA-2S)
THD+N over Output Power 2x 1 mW...1500 mW 1 kHz at 2x 62 Ω (LPA-2S), Bw 22 kHz
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