MP-701 MK3 Tube Preamp Pre Amplifier

MK3 version changelogs:

1. PCB boards color is changed from green to purple.

2. Internal shielded interconnect cables are separated between all 3 input channels to minimize crosstalk.

3. The power filtering choke is upgraded to a bigger one from 3H to 20H and relocated to the bottom compartment of the chassis to provide the lowest noise floor.

4. Two filament voltages are regulated by a linear LDO regulator.

After two years of R&D, we are glad to announce the second edition of MP-701 tube preamp. The circuit has been fully redesigned to provide extraordinary sound performance, low noise floor and better compatibility with different types of power amps in the market. It can work with integrated amplifiers, power amplifiers and active speakers. Don’t like passive preamp integrated in most source devices, such as DAC, standalone MP-701 MK2 tube preamp is guaranteed to bring your HiFi system performance to the true next level. It is not just a volume control machine. It truly brings out more sonic details, dynamic, stronger bass, wider and deeper sound stage to the audience.

User Reviews

https://youtu.be/O6m9maqmxmM

Technical highlights

1. Onboard filament voltage switches allow support both 6.3V and 5V rectifier, 6.3V and 12.6V signal tubes.

2. Onboard DIP switches allow user to select 4 different levels of output gain to support different input sensitivity of amplifiers.  

3. Zero negative feedback circuit provides the most natural sounding.

4. Oversized 150W toroidal transformer provides sufficient power redundancy. It is magnet shielded in the compartment underneath the motherboard.

5. Output coupling capacitors and power filtering bypassing capacitors are user changeable to further improve or customize the overall sound characteristics. No soldering is required.

6. Built with genuine HiFi grade components, such as Vishay military grade resistors, Genuine Rubycon and Nichicon LOW ESR power filtering capacitors, OHVL coupling caps, Bennic XPP bypassing capacitors, ALPS volume control and power switch, heavy gold-plated terminals.

7. Solid aluminum alloy case, suspension feet and knobs.

8. Remote volume control feature.
 

Specs

1. Output voltage: 20V (Max) depending on DIP switches gain settings and the type of signal tubes.

2. Output impedance: 2Kohm (Recommended power amp input impedance >=10Kohm)

3. Input impedance: 100Kohm

4. Frequency Response: DC to 50khz

5. Input: RCA x 3, XLR x 1

6. Output: RCA x 2, XLR x 1

7. Sub-woofer support: Yes

8. Dimensions: W 31cm x D 39cm x H 15.5cm

9. Gross Weight: 12 kg

10. Input Voltage: 110-120V / 220-240V

Tubes

1. 6.3V filament rectifier tubes: 6Z5P, 6X5.

2. 5V filament rectifier tubes: 5R4, 5U4G, 5AR4, GZ33, GZ34, 274B, 5Y3, 5Z3P.

3. 6.3V signal tubes: 6N11, 6N1P, E88CC, E188CC, CCA, 6922, 6H23, 6H6, 6H30, 6CG7, (6SN7 with 6SN7 to 6922 adapter).

4. 12.6V signal tubes: 12AU7, 12BH7, E80CC, (12SN7 with 6SN7 to 6922 adapter).

When using 6.3V filament rectifier tubes, onboard S2 switch must set to 6X5 position. When using 5V filament rectifier tubes, onboard S2 switch must set to 5AR4 position.

When using 6.3V filament signal tubes, onboard S1 switch must set to 6.3V position. When using 12.6V filament signal tubes, onboard S1 switch must set to 12.6V position.

Capacitors

1. Stock Obbligato gold coupling capacitor is 630V 2.2UF. Capacitance can be 1.5UF – 4.7UF. Voltage needs to be >=350V. Nonpolar.

2. Stock Bennic power filtering bypassing capacitor is 350V 6.8UF. Capacitance can be 0.1UF – 10UF. Voltage needs to be >=350V. Nonpolar.

Warranty

1 Year (One month for tubes)

*Note: MP-701 MK2 is based on single ended circuit. XLR is converted from RCA for convenience, so user can use existing XLR cables.

Manual

English V1.0