MP7B: 68V Discrete J-FET RIAA MM+LOMC Phono Preamplifier w/EQ Trim (+35 to +72dB)

MP-7: Fully-Discrete, Zero Negative Feedback, Single-Ended Class-A High-Voltage Pure J-FET (Junction Field Effect Transistor) Phono Preamplifier

Get truly high end, truly musical sound with hand-built USA quality, from an engineering team with 50+ years experience.

• Optimized Multi-Purpose (MP) - truly optimized for four different scenarios. 1) High Quality MM, MI and HOMC cartridges via the main +40dB stage, 2) Low-Output Moving Coils via our unit’s own internal active LOMC step-up stage, 3) Outboard Step-Up-Transformers (SUTs), or 4) Separate external active Head Amps (like our SU series).

• Zero Feedback, Single-Ended Class-A Gain Stages - No Op-Amps (Integrated Circuits) and no Differential FET operation - for more natural sound, cleaner crescendos and minimal listening fatigue

• Enhanced Power Supply Regulation - Derived directly from the most elegant and technically sophisticated power supply ever utilized in a DLabs product (our MP8B). The MP7B uses a single version of this great power supply regulator. It allows a higher rail voltage that the predecessor, provides increased resilience against poor AC power, and provides superior clarity of sound, great ‘punch', soundstaging, power and dynamics.

• LOMC capabilities built in

• High Headroom Passive RIAA equalization

• High-Voltage J-FETs -Hand-matched with hand-tuned operating points deployed in a maximum-inherent-linearity configuration

• Extensive local decoupling networks provide deep, wide and immersive soundstaging

• Mono Switch available at extra cost

• Black Front Panel (Silver Front Panel available only in Fully Loaded Configuration as of May 31, 2025)

• Blue LED with user-variable brightness

• Upgraded jacks available at extra cost - provide enhanced appearance together with increased reliability across multiple connection/disconnection cycles.

• Hand-soldered, assembled and calibrated by experienced US-paid craftsmen

• Through-hole construction for electrolytic capacitors and other critical parts, conservatively rated, long life audiophile quality components

• Listen 5 to 7dB louder without strain or fatigue than competitive products for greater perceived dynamics and musical immersion

• Invites comparison to products up to $3000 or more

• DETAILED FEATURE LIST:

• Gain is variable between +35dB, +37dB, +40dB, +49dB, +51dB, +54dB, +61dB, +63dB, +66dB, +67dB, +69dB, +72dB (LOMC stage is built-in)

• Usable with most any cartridge of 0.1mV to 10mV nominal output i.e., nearly all and also optimized for your SUT - see below.

• LF EQ Trim (+0.75dB and +1.5dB at 20Hz, shelving response)

• HF EQ Trim (-4dB to +4dB at 20kHz in shelving response, with many intermediate steps)

• Subsonic Filter (switchable): Flat, or 16Hz HPF at 6dB/octave or 12dB/octave.

• Variable Resistive loading for MM-level: 38K, 44K, 47K, 62K, 92K, 150K, 240K or 1Meg (these include settings optimized for use with external third-party SUTs (Step-Up Transformers).

• Variable Resistive loading for LOMC-level (gains of +49dB or greater): 60 ohm, 69 ohm, 82 ohm, 100 ohm, 150 ohm, 220 ohm, 470 ohm, or 62K.

• Variable capacitance MM: 0pF, 50pF, 100pF, 150pF, 200pF, 250pF, 300pF, 350pF

• Balanced output capability (with user-supplied custom connecting cable)

• Balanced Power Supply Generation (BSG) for minimum background hum even in difficult or noisy AC line conditions

• +68V Main Voltage Rail with 30V LOMC voltage rail.

• Monostrapping possible via an internal jumper (for running a dedicated mono cartridge or TT without having purchased the external Mono switch)

• User-variable LED Brightness.

• Black or Silver front available (you can change the color by purchasing a new front panel and installing it yourself!)

• Upgraded Jacks available at extra cost.

• Mono Switch available at extra cost.

SPECIFICATIONS:

Distortion: 0.07% THD, 1kHz at 0.5V out into 10K load; 0.007% 3HD and higher, 1kHz at 0.5V into 10K load

S/N:  >78dB A-Wtd re: 5mV input with simulated inductive standard MM type cartridge as a source (40dB gain); >71dB A-Wtd re: 0.5mV input with 10 ohm source (LOMC mode: +47 to +72dB settings)

Maximum Output:  19V RMS (27.5dBu or 52V pk-pk) at 1kHz into 10K load.

Frequency Response: RIAA: +/-0.2dB from 20Hz to 20kHz

Bandwidth: -1dB at 7Hz and 70kHz.

Input Overload: 145mV at 1kHz input. 

Size: 7” D x 5 1/8” W x 1 9/16” H. Weight: 2.5 lbs. Packed weight: 3.5 lbs.

External Power Supply Cube: 24VAC 500mA, available in US 120V, EU 230V, UK 230V or AUS/NZ 230V.r EU 230V AC input.