Specifications
RECORDING & BROADCAST
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S
tudio Reference Series™ amplifiers are engineered for the critical
demands of recording studios. Featuring an extremely wide dynamic
range and ultra-low harmonic and intermodulation distortion, these amps
provide the best sonic accuracy in the business. They also feature a damp-
ing factor of better than 20,000 for a tight, well-defined low end. Patented
ODEP circuits detect and compensate for any demanding load condition,
while optional PIP modules let you customize the amplifier to your needs.
`SPECIFICATIONS
Performance
Frequency Response (at 1 watt) 20 Hz to 20 kHz:
±0.1 dB.
Phase Response (at 1 watt, 20 Hz to 20 kHz):
+5 to –15 degrees.
Signal-to-Noise Ratio (below rated full bandwidth
power), A-weighted:
Studio Reference I: > 120 dB.
Studio Reference II: > 117 dB.
Total Harmonic Distortion (THD) (at rated power),
20 Hz to 20 kHz: < 0.1%.
Intermodulation Distortion (IMD) (60 Hz and
7 kHz at 4:1):
Studio Reference I: Less than 0.005% from full
bandwidth power to 78 watts rising linearly to
0.025% at 78 milliwatts.
Studio Reference II: Less than 0.005% from full
bandwidth power to 36 watts rising linearly to
0.025% at 36 milliwatts.
Damping Factor, 10 Hz to 400 Hz: >20,000.
Voltage Gain (at maximum level setting, ±1 dB):
Studio Reference I: 40-dB gain at 0.775-volt sensi-
tivity; 35-dB gain at 1.4-volt sensitivity; 26-dB gain
at 26-dB sensitivity.
Studio Reference II: 37-dB gain at 0.775-volt sensi-
tivity; 32-dB gain at 1.4-volt sensitivity; 26-dB gain
at 26-dB sensitivity.
Crosstalk (below rated power, 20 Hz to 20 kHz):
Studio Reference I: > 70 dB.
Studio Reference II: > 65 dB.
Common Mode Rejection (CMR)(20 Hz to 1 kHz):
>70 dB.
Input Impedance: (balanced, unbalanced): 20 k
ohms, 10 k ohms.
Load Impedance: Safe with all types of loads.
Rated for 4 to 8 ohms in Stereo mode; 8 to 16
ohms in Bridge-Mono mode; 2 to 4 ohms in
Parallel-Mono mode.
Output Impedance: Less than 10 milliohms in
series with 2.5 microhenries.
DC Output Offset (shorted input): < ±2 millivolts.
Required AC Mains (±10%): 50/60Hz, 100 to
240 VAC.
Power Draw at Idle: 90 watts or less.
Front Panel Controls
Enable: Push button used to turn the amplifier on
and off.
Level: 31-detent, rotary level control, one for each
channel.
Meter On/Off: Turns the meters on or off.
Meter Display Mode: Sets the display mode for
the front-panel meters: Dynamic range of the out-
put signal in dB or output levels in dB.
Back Panel Controls
Ground Lift Switch: Two-position switch isolates
the input phone jack and AC (chassis) grounds.
Sensitivity Switch: Selects the input sensitivity for
both channels: 0.775 or 1.4 volts for standard 1
kHz power, or a 26-dB voltage gain.
Stereo/Mono: Selects Stereo, Bridge-Mono or
Parallel-Mono mode.
Reset: Resets the AC mains circuit breaker.
Front Panel Indicators
Enable: Shows the on/off status of the unit’s
low-voltage power supply.
Signal: Flashes to show audio output in each
channel.
IOC: Flashes if the output waveform differs from
the input waveform by 0.05% or more. The LEDs
act as sensitive distortion indicators to provide
proof of distortion-free performance. In Parallel-
Mono mode, the Channel 2 IOC light stays on.
ODEP: An LED for each channel shows thermal-
dynamic energy reserve. Lit LED incdicates avail-
able reserve energy. If a channel has no reserve,
its indicator will dim in proportion to ODEP limiting.
Dynamic Range/Level Meter: Displays either the
dynamic range of the output signal in dB (factory
default), or the output level in dB. As dynamic
range meters, they show the ratio of the peak to
average power of each channel. As output level
meters, they show the output levels relative to
standard 1 kHz power.
Input Connectors
Two balanced phone jacks on the back panel and
two balanced three-pin XLR connectors on the fac-
tory-installed P.I.P.-FX module.
Output Connectors
Two sets of color-coded, 5-way binding posts
accept banana plugs, spade lugs or bare wire.
(European models do not accept banana plugs.)
Protection
Studio Reference amplifiers are protected against
shorted, open or mismatched loads; overloaded
power supplies; excessive temperature, chain
destruction phenomena, input overload damage and
high-frequency blowups. They also protect loud-
speakers from input/output DC and turn-on/turn-off
transients by means of a 4-second turn-on delay.
Cooling
Convection cooling with assistance from the com-
puterized, on-demand proportional cooling fan.
Dimensions
EIA Standard 19-inch (48.3-cm) rack mount width
(EIA RS-310-B), 7-inch (17.8-cm) height and 16-
inch (40.6-cm) depth behind the mounting surface.
Weight
Net Weight:
Studio Reference I: 60 lbs. 11 oz. (27.6 kg);
Studio Reference II: 56 lbs. 2 oz. (25.5 kg).
Shipping Weight:
Studio Reference I: 74 lbs. 3 oz. (33.7 kg);
Studio Reference II: 69 lbs. 10 oz. (31.6 kg).
Accessories
IQ Network Accessories: Accepts most
PIP modules. Can accept IQ-PIP Lite
module when paired with the IQ-PIP USP2
Adapter Kit (some functionality will be limited).
Regulatory Certifications
Other Applications
All measurements apply to units in Stereo mode with 8-
ohm loads and rated input sensitivity unless otherwise
specified.
Studio
Reference I
Studio
Reference II