Input Impedance	150-3000 (Omega) Adjustable (XLR), >800k (Omega) (Instrument)
Output Impedance	< 47 (Omega) (XLR)
Maximum Input Level	+19 dBu (Cannon)
Maximum Output Level	+27 dBu (XLR)
Maximum Gain	75 dB
Frequency Response	15 Hz to 48 kHz (+0, -1 dB) @ Normal Plate Voltage 15 Hz to 120 kHz (+0, -1 dB) @ High Plate Voltage
Total Harmonic Distortion	<0.005% (Typical)
Equivalent Input Noise	-129 dBu (XLR, “A” Weighted)
CMRR	>90dB
Power Requirements	USA – 105 to 125 VAC / 60 Hz Export Units Configured forCcountry of Destination

Category	Specification
Type	Stereo headphone amp (4 channels)
Analog Inputs	1× ¼″ TRS, 1× ⅛″ TRS (parallel wired)
Headphone Outputs	4× ¼″ TRS + 4× ⅛″ TRS
Max Input Level	+14 dBV
Input Impedance	90.9 kΩ
Max Gain	+20 dB
Max Output Level	+14 dBu
Output Impedance	47 Ω per output (others list ≈51 Ω)
Frequency Response	20 Hz – 20 kHz
SNR	>90 dB (ref 0 dBu)
THD	<0.01%
IMD (SMPTE)	0.01%
Power Supply	12 V DC adapter included
Dimensions (H×W×D)	47 × 117 × 104 mm (1.85″ × 4.6″ × 4.1″)
Weight	0.61 kg (1.3 lb)
LED Indicators	Power-on LED
Chassis	Custom extruded metal, stackable
Warranty	3 years (manufacturer)

Inputs	XLR, 1/4″
Outputs	XLR, 1/4″
Input Impedance	40K Ω Main, 10K Ω Direct, 15K Ω Aux In
Output Impedance	<12 ΩHeadphones
Maximum Input Level	+21 dBu
Maximum Output Level	150mW (600 Ω Headphones) 500mW (32 Ω Headphones) 150mW (8 Ω Headphone
Maximum Gain	22 dB
Total Harmonic Distortion	<.01% Typical
Signal to Noise Ratio	>90dB Typical
CMRR	>40 dB
Power Requirements	120 VAC / 50-60 Hz, or 230 VAC / 50 Hz, 15 W
Dimensions (LWH)	6″ x 19″ x 1.75″, 15.2 cm x 48.3 x 4.45
Weight	5.3 lbs. (2.4kg)

Category	Specification
Type	8‑channel headphone mixing/distribution amplifier (1 U rack)
Amplifier Channels	8 independent high‑power stereo amplifiers, each with level control and LED meter
Main Inputs	2 × stereo (Main In 1 & 2), ¼″ TRS, servo-balanced
Main Input Impedance	Balanced: 40 kΩ; Unbalanced: 20 kΩ
Max Main Input Level	+16 dBu (some sources list +22 dBu)
Direct Inputs	8 × independent ¼″ TRS (one per channel)
Direct Input Impedance	~15 kΩ
Phone Outputs	16 × ¼″ TRS (8 front, 8 rear), dual per channel
Max Output Level	+24 dBm into 100 Ω, +19 dBm into 8 Ω
Minimum Load Impedance	8 Ω
Frequency Response	10 Hz – 150 kHz, ±3 dB
Dynamic Range	~101–103 dB (22 Hz–22 kHz)
Signal‑to‑Noise Ratio	> 87 dB or > 90 dB depending on spec
THD + N	~0.006–0.007 % @ +4 dBu, 1 kHz
Controls (per channel)	Output level knob, Main In 1/2 select, Mono/Stereo switch, 8-digit LED meter
Master Controls	Two Main Input level dials, 5-segment Input LED meter
Power Supply	“Planet Earth” switching supply (100–240 V AC autorange), draws ~35 W
Dimensions (H×W×D)	44 × 483 × 149 mm (1.75″ × 19″ × 5.9″)
Weight	~1.9 kg (4.2 lb)
Warranty	3 years (varies by region)

Category: PRE AMP

ART Digital MPA-II 2-Channel Tube Preamp with Digital Connectivity