MM6B: 68V Discrete J-FET RIAA MM-level Phono Preamplifier (+35 to +40dB)

MM6B: Fully-Discrete, Zero Negative Feedback, Single-Ended Class-A High-Voltage Pure J-FET (Junction Field Effect Transistor) Phono Preamplifier

Why settle for underwhelming performance from the well-known names?

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

• 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 MM6B shares the bulk of the power supply from the MP7B.

• 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 is available at extra cost

• Black Front Panel

• Blue LED with user-variable brightness

• 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 4 to 6dB louder without strain or fatigue than competitive products for greater perceived dynamics and musical immersion

• Invites comparison to products up to $1500 or more.

DETAILED FEATURE LIST:

Gain: +35dB, +37dB or +40dB (for use with most any MM, MI, and HOMC cartridge having an output level of 1.6mV or greater). Use an external Step-Up Transformer (SUT) or an Active Head Amp (like our SU-6 or SU-7) for an LOMC cartridge with less than 1.5mV output.

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

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

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

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

Balanced Power Supply Generation (BSG) for low background hum in even difficult or dirty AC line conditions.

+68V Main Voltage Rail provides excellent headroom for good sound and low audible surface noise

LED Color: Blue w/User-variable brightness

Mono Switch available at extra cost

Black front panel

SPECIFICATIONS:

Distortion: 0.08% THD at 0.5V out, 1kHz into 10K load; 0.008% 3HD and higher, 1kHz at 0.5V into 10K load

S/N: 77dB A-Wtd re: 5mV input with simulated inductive standard MM type cartridge as a source (40dB gain).

Maximum Output: 19V RMS (27.5dBu or 50V pk-pk) at 1kHz into 10K load.

Frequency Response: RIAA: +/-0.23dB from 20Hz to 20kHz

Bandwidth: -1dB at 8Hz and 70kHz.

Input Overload: 140mV at 1kHz input. 

Size: 7” D x 5 1/8” W x 1 9/16” H. Weight: 2.2 lbs. Packed weight: 3.3 lbs.

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