"Metal Heart MC" RIAA phono preamplifier combined with famous Hiraga system active low-noise solid-state direct-coupled MC Headamp.
This system consists of two separate pre-amps, both are possible to be used separately or combined way.
The system gives possibility to use RIAA-correction tube type preamp, wich has very wide dynamics and spacious sound, combined with possibility to use low-noise direct-coupled active headamp to match Moving Coil cartridges signal level. The result is a combination of both technologies best sides: tubes large dynamics and solid state components low-noise pre-amplification needed for MC-cartridges.

As both pre-amps are actually fully separate and independent with their own inputs and outputs, it is possible to use both independantely: as for RIAA-correction pre-amp for MM or MI type of cartridges and also to use the MC-Head-amp separately for stepping-up the signal for other RIAA-correction pre-amps (instead of MC step-up transformers). Best result for MC-cartridges pre-amplification will appear when both pre-amps are combined, please see the images below.
Large clear window on top cover allows to see all these interesting guts of this apparatus.


Parameters:
Input signal MC input: 0,3...3,0 mV
Input signal MM input: 3...30 mV
Input impedance: 47 kOhm (MM Input standard)
Suitable MC-cartridges impedance: 10 Ohm ... 150 Ohm (all MC-cartridges)
Output signal: 500+ mV (Line level)
Amplification for RIAA-correction preamp: 40 dB @1 kHz
Amplification for MC-headamp: 20 dB @full band
Correction: RIAA, passive
Tubes: 6SQ7 (6Г2), 6SR7 (6Г1)
Power consumption: 40W
Dimensions: 430 x 260 x 120 mm.
Weight: 8 kg

 2018