Features

 

• High quality handcrafting with module style line amplifier section, best component placements, signal wiring and ground layout.
• Strong power supply section along with 700uF huge reservoir by combining 3 types of capacitor in individual left and right channel. Delivering natural and stress-free music over the whole frequency band.
• The newly developed DC heater circuit uses all premium parts selected through long time listening tests.

 

Design

 

Being the center of an audio system, the character of a preamplifier is very important. In addition to passing all specifications of modern amplifier, we also pursued to get refine and elegant sound quality.

• Main circuit is simple and direct to obtain low output impedance and music freshness. It is just a plate follower direct couple to a cathode follower. Vacuum tubes adopted are 6072.
• By using direct components wiring on a module board, the shortest signal paths are possible.
• Adopt quality parts such as SSW (silk silver wire), silver foil capacitors, original power transformer and copper chassis.
• Tonal quality is enhanced by the newly developed DC heater circuit.
• Sound quality is elegant, smooth, natural and without any coloration.

 

Line Unit

 

Line amplifier section is direct components wiring on a module board to get the benefit of direct wiring and shortest signal paths.
Moreover, decoupling capacitors are arranged for each individual left and right channel. This keep the overall signal loops to the minimal lengths.
New circuit design which had already considered to keep good low frequency performance up to 20Hz when the connecting to low input impedance solid state amplifier (e.g. 20kΩ)

 

Super High Quality Parts

 

All parts were carefully chosen after massive hours of listening tests. High grade audio volume, copper chassis, original silver foil capacitors, original electrolytic capacitors, silver lead resistors, 3 types of metalized film resistors, SSW silk silver wires, Ls-41 shield cable, original RCA jacks, high quality power transformer etc. All CR part are carefully selected and arranged.

 

Power Supply Circuit for Main and Filament

 

Rectification tube in use is 6X4. Power transformer design, which we paid high attention to vibration countermeasures, was fixed after long time of listening tests and comparisons. Ripple filter capacitors (400μF) and decoupling capacitors (about 700μF /ch) are layout at the best circuit positions. They all work together to create a power supply section. 700uF huge reservoir by combining 3 types of capacitor 600+100+0.47μF) are used in each left and right channel to deliver the best tonal balance. There are also a lot of tests carried out to select the best circuitry and components.

 

Specifications

 

Product	Stereo line preamplifier
Model	G-70 i
Frequency Response	10Hz ～ 240kHz (+0dB -3dB, with 100kΩ load)
Gain	25dB
Input / Impedance	4pairs(RCA, Unbalanced) / 50kΩ **2021/4 100kΩ→50kΩ
Output	2 pairs (RCA, over 20kΩ load)
Noise	lower than 0.15mV
Tubes	6072 x2, 6X4 x1
Power consumption	21W
Dimension	303mm(W) 160mm(H) 408mm(D) (Excluding protrusions)
Weight	17.5kg