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The Atma-Sphere MP-1 Mk. 3.3 is a world-class, fully differential and balanced vacuum tube preamplifier that supports the Balanced Line standard (AES48), eliminating interconnect cable coloration and noise. It features a patented direct-coupled Circlotronic® output stage with zero feedback and dual-mono construction, providing wide bandwidth, low distortion, and dynamic range. The phono section offers approximately 66 dB gain with RIAA accuracy within 0.07 dB and supports very low output moving coil cartridges. The line stage gain is 12 dB with a frequency response from 0.1 Hz to 400 kHz. The unit includes precision 24-position stepped volume control built from a Shallco® custom switch, Teflon® custom coupling capacitors, and low-noise star grounding. The power supply is fully regulated and isolated in a separate chassis. The MP-1 Mk. 3.3 is capable of driving 32-ohm headphones and includes XLR connectors for balanced inputs and outputs, with optional RCA inputs and outputs. It weighs 42 lbs per chassis and measures 13" deep x 17" wide x 5.5" tall per chassis, with a 19" wide x 6" tall faceplate. The preamplifier requires a warm-up period of about 1-2 hours for optimal sound and comes with a three-year transferable warranty and one-year warranty on tubes.
Analog signal output specifications
Phono stage specifications
Input and output connections
Size, weight, and appearance
Specifications are community-contributed and may not be accurate or complete. Verify all details with the manufacturer before making purchasing decisions. Terms & Conditions
The closest alternatives on specs, description and the systems they turn up in, with the specs they share set side by side.
The VK-53SE's output voltage is 40.0V RMS against the MP1 Mk. 3.3's 32.0V RMS, its output impedance 200Ω against 30Ω, and its weight 20.4 kg (45 lbs) against 19 kg (42 lbs). Both share input impedance (100000Ω).
The No. 52's output impedance is 10Ω against the MP1 Mk. 3.3's 30Ω, its output voltage 8.0V RMS against 32.0V RMS, and its weight 27 kg (60 lbs) against 19 kg (42 lbs). Both share input impedance (100000Ω).
The NU-Vista PRE's output impedance is 47Ω against the MP1 Mk. 3.3's 30Ω, its output voltage 28.0V RMS against 32.0V RMS, and its weight 22 kg (49 lbs) against 19 kg (42 lbs). Both share input impedance (100000Ω).
The KRC-HR's output impedance is 5Ω against the MP1 Mk. 3.3's 30Ω, its output voltage 14.0V RMS against 32.0V RMS, its input impedance 47000Ω against 100000Ω, and its weight 5.25 kg (12 lbs) against 19 kg (42 lbs).
Conrad Johnson GAT
Octave Audio HP 300 SE
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