Bryston BHA-1 User Manual

BHA-1 HEADPHONE AMPLIFIER
DRIVING MULTIPLE PAIRS OF HEADPHONES
While the BHA-1 is capable of driving multiple pairs of headphones from its three outputs (single 4
pin XLR jack, dual 3 pin XLR jacks and 1/4” stereo phone jack) the resultant load impedance should
always be greater than 32 Ohms. Note that the three outputs are all in parallel and are all driven from
the same output amplifiers.
To calculate the load of two and three pairs of headphones being driven simultaneously:
Where A is the load of the 1st pair of headphones in Ohms, B is the load of the 2nd pair and C is the
load of the 3rd pair of headphones:
Load of 2 parallel headphones = 1/((1/A)+(1/B))
Load of 3 parallel headphones = 1/((1/A)+(1/B)+(1/C))
BHA-1 SPECIFICATIONS
Power Output: Maximum: 6 Watts per channel into 32 Oms
Nominal: 500 milliwatts per channel into 50 Ohms
Input Impedance: 10K ohms single ended (unbalanced)
+15K/-5K ohms double ended (balanced)
Sensitivity: 20 dB setting: 0.707 Volts in = 1.0 Watts into 50 ohms
14 dB setting 1.411 Volts in = 1.0 Watts into 50 ohms
20 dB setting: 0.500 Volts in = 500 mW into 50 ohms
14 dB setting 0.998 Volts in = 500 mW into 50 ohms
Distortion: THD+noise: < 0.005% 20 Hz to 20 kHz
IMD: < 0.001% 60 Hz + 7 kHz mixed 4:1
Noise: Measured with input shorted (20 Hz to 20 kHz.)
>103 dBv (with 20 Hz to 22 kHz band pass filter)
Frequency Response: 20 Hz to 20 kHz @ ± 0.1 dB.
Power Bandwidth: <1 Hz to over 100 kHz
Power consumption: 50 Watts
Heat load: 130 BTU/hr
Dimensions: Maximum overall dimensions with C-series front panel & feet:
17” dress panel: 2.713” high & 11.1” deep (432mm • 69mm • 282mm)
19” dress panel: 2.713” high & 11.1” deep (483mm • 69mm • 282mm)
Maximum overall dimensions with Rack mount panel & feet:
19” wide, 2.45” high & 11.1” deep (483mm • 62.2mm • 282mm)
Maximum overall dimensions with Rack mount panel but without feet:
19” wide, 2.45” high & 11.1” deep (483mm • 62.2mm • 282mm
(See page 8 for more details)
Weight: unit alone: 11.7 lbs (5.3 kg) approx.
with packaging 16.5 lbs (7.5kg) approx.

Bryston BHA-1 Specifications

General

Type	Headphone Amplifier
Frequency Response	20 Hz to 20 kHz ±0.1dB
Input Impedance	50kΩ
Inputs	2x XLR, 2x RCA
Outputs	4-pin XLR, 1/4 inch TRS
Gain	20dB high gain
Total Harmonic Distortion	Less than 0.005%
THD+N	Less than 0.005%