70V Direct-Drive Operation:
The Xi1850 and the Xi2600 have sufficient output voltage capability in stereo mode to direct-
drive 70-volt distribution systems without using a step-up transformer at the amplifier. In this
configuration, the Xi1850 delivers up to 370 watts per channel and the Xi 2600 500 watts per
channel to the 70V system, depending on the impedance of the total system. As with all 70V
systems, step-down transformers are still required at each loudspeaker.
The Xi1850 can deliver
370 watts per channel into an 8 ohm impedance (54.41V line voltage). The Xi2600 can deliver
500 watts per channel into an 8 ohm impedance (63.25V line voltage).
The price for going direct is having to calculate the new transformer tap values at the new line
voltage. Since watts are proportional to the square of the voltage, compute the correction factor
by taking the ratio of the square of the line voltages. then multiply each tap value by this correction
factor. For example, choose a transformer that has tap values at 10W, 5W and 2.5W when used
in a 70.7 volt distributions system.
Its new tap values when used with an Xi1850 are computed as follows:
1) Complete correction factor K:
K=54.41V
2
/70.7V
2
K=0.59
2) Apply to tap value:
10W x 0.59= 5.9W
5W x 0.59= 2.95W
2.5W x 0.59= 1.74W
Its new tap values when used with an Xi2600 are computed as follows:
1) Complete correction factor K:
K=63.25V
2
/70.7V
2
K=0.80
2) Apply to tap value:
10W x 0.80= 8.0W
5W x 0.80= 4.0W
2.5W x 0.80= 2.0W
When used in a 70.7 volt distribution system, this transformers new tap values are as noted
above. Note that the 3dB power relationship between each tap still holds true. Similarly, maximum
amplifier loading occurs when the sum of the New tap values equals the amplifiers output
power per channel into the 8-ohm load.
9
THD+N:
<0.5% @ rated power (8 ohm), 20-20kHz
<0.5% @ rated power (4 ohm), 20-20kHz
1% @ rated power (2 ohm), 1kHz
1% @ rated power (8 ohm), bridged
1% @ rated power (4 ohm), bridged
IMD (SMPTE):
<0.2%, 60Hz/7kHz, 4:1, 35Vpeak @ 4 ohms
Dynamic Headroom:
1.5dB
Power Bandwidth:
20-20 kHz @ 4 and 8 ohm loads
Frequency Response:
20-20kHz, +0dB/-1dB
Signal-to-Noise:
>100dB, A-Weighted, referenced to 4 ohm rated power
Crosstalk:
>
-70dB @1kHz referenced to rated power (4 ohm)
CMRR:
70dB at 1kHz
Slew Rate:
20V/uSec
Sensitivity for rated power
:0.775Vrms or 1.55Vrms (Selectable)
Input Impedance
:50k balanced
Input Overload
:20dBu
Protection:
Thermal, Short Circuit, Over-Current & Over Voltage
Stability:
Unconditionally stable into reactive loads at 1/3 rated output power
Duty Cycle:
Continuous operation at 1/3rd power
POWER REQUIREMENTS:
Mains Voltage (output power rated at nominal voltage):
100V
AC
(50-60Hz) ±10%
117V
AC
(60Hz) ±10%
234V
AC
(50Hz) ±10%
Current consumption @ 1/8 rated power, pink noise:
Xi2600
8-ohm x 2 500W (7.0A) 117V/60Hz 400W (2.8A) 234V/50Hz
4-ohm, x 2 700W (10A) 117V/60Hz 600W (4.0A) 234V/50Hz
2-ohm x 2 1250W (15A) 117V/60Hz 1100W (7.5A) 234V/50Hz
Xi1850
8-ohm x 2 340W (4.9A) 117V/60Hz 340W (2.3A) 234V/50Hz
4-ohm x 2 525W (7.2A) 117V/60Hz 525W (3.5A) 234V/50Hz
2-ohm x 2 850W (10.8A) 117V/60Hz 825W (5.3A) 234V/50Hz
Performance Specifications
Xi1850 / Xi2600
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