Monrio MP Line – Preamplifier


Combining the most advanced, triode/junction FET hybrid topology and  solid-state regulation – without any feedback –  the MP Line is a remarkable performer. This also reduces the output impedance to about 100 ohms – capable of driving any power amplifier, tube or solid-state. It is the answer to the impassioned quest by music lovers for a high performance, reliable and affordable tube preamp. While conventional tube preamps have always been recognized as the ultimate, and expensive, way of listening to music there have been serious impediments to wider scale use. The rumors you heard about conventional tube circuitry are true, tube preamp are expensive, tubes can get noisy and you can’t get much gain from a tube circuit. The MP Line hybrid tube/FET circuit eliminate all of these conventional problems and gives you the sound quality of tube and the reliability of solid state. The only way to bring the sound quality of tubes to the masses is by eliminating the tube tremors. By integrating FETs with tube we eliminate all the weakness of tubes and preserve their unique ability to reproduce real music.  The preamp circuitry uses FETs in those sections that are stressed and usually create noise, in addition, the FETs eliminate all tube microphonics.  In the MP Line all of the audio information appearing at the input including imaging, dynamics, purity, and musicality are preserved completely and delivered to the output without any distortion or alteration. One of the design factors that is responsible for the MP Line level of performance is the sophisticated multiple tiered solid-state regulated power supplies independent for each channel. A toroidal  transformer, with various secondary wiring, provides the separate voltages for filament, high voltage, FET input stage and services. The 6922/1N6P has 220VDC  fully regulated by a transistors regulators. Its filament is powered at 6.3VDC from a filtered and regulated supply. The choice of full regulated power supply allows the tube to receive stabile and clean power supply. The switch-on is delayed, through a relay, in order to preserve tube life.


Instead of chassis wiring which can create sonic problems, the MP Line has no wiring. There is a small amounts of wiring required to connect signals between input/output PC Board and gain block PC Board.

The construction of the MP Line is at once simple, careful and robust, it uses a bottom plate in steel which support PC Boards and power transformer. Top cover is   made in aluminium silver anodized.

Faceplate is built on 10mm thick of machined aluminium. Finish is silver brushed and anodized. Knobs are machined from solid aluminium, hand polished and silver finish.


Control functions include on/off power switch, input selection and volume. Volume is remotely controlled by a supplied remote handset. Four single-ended input and two balanced input sources are accommodated, with two sets of single-ended main outputs, stereo balanced XLR and one set of fixed-level tape outputs. It is equipped with Bluetooth 5.1 receiver with DAC on-board. The passive components are of top quality:  tube socket is ceramic; metal film 1% precision resistors are used all over the circuit; power supply decoupling capacitors are double-bypassed utilizing polypropylene caps for more linear high-frequency current delivery with no compromise to speed or extension. On  the output stage an oil impregnated metallised paper dielectric capacitor has been chosen for its long-term capacitance stability that achieve really constant performance in audio reproduction. Standard version is supplied with the ALPS RK27 (blue beauty) motorized volume potentiometer. Alternatively, a very High Performance version is also available equipped with a manual potentiometer from the Japanese TKD. Ask for availability and cost before ordering


Gain: 22dB
Frequency Response: 10Hz – 150kHz, +/-1dB
Max output level: 10 Volts
Distortion: THD 0.1% – 1kHz
Output Impedance 120 ohms
Balanced Input and Output
Motorized ALPS RK27 Volume potentiometers or TKD 2CP-2511
Bluetooth 5.1 – Support SBC, AAC, APTX, APTX-HD, LDAC
DAC: ES9018K2M – 32BIT/384kHz
Power Supplies: Fully-regulated low and high voltage supplies
Tub complement: 1x 6922/E88cc or 6N1P) dual triode
Power consumption 25 watts
Dimensions: 438 x 92x 325 mm (WxHxD)
Weight : 7,5 Kg.