VS70.1 power amplifier

 

VS70.1 is an improved version of our popular VS70 stereo power amplifier. VS70.1 closely follows the design from the mono-block power amplifier VM60. Except that VS70.1 uses lower power tubes and output transformer, the design of the amplifier follows the same patented Dual Balanced Feedback Topology (DBFT).

The improvement includes: optimized amount of feedback using in DBFT; enhanced DC power filtering capacitance; redesigned of all PCBs and moved the power switch from the rear to the front panel. These improve sonic performance as well as operation convenience.

The power amplifier design employs two patented circuits that make the VS70.1 a truly balanced power amplifier. Input signals are amplified in true balanced mode starting from the input stage to the output transformer. No solid-state transistors and integrated circuits are used for signal amplification. Since a fully balanced mode is effectively operating, external electromagnetic noises picked up by audio cables can be easily cancelled out.

 

 

CIRCUIT DESIGN
Dual Balanced Feedback Topology (DBFT) design

VACUUM TUBES
4 x 12AX7/ECC83, 2 x 6DJ8/6922, 4 x KT77

POWER OUTPUT
35 watts per channel into an 8 or 4 ohm load

OUTPUT LOAD IMPEDANCE
Terminals for 8 and 4 ohm

TOTAL HARMONIC DISTORTION
0.1% @ 10W, 1kHz, 8 ohm load
1% @ 35W, 1kHz, 8 ohm load

FREQUENCY RESPONSE
20Hz to 20kHz

INPUT SENSITIVITY
1V balanced

SIGNAL TO NOISE RATIO
85dB (Balanced input)

INPUT IMPEDANCE
> 22k ohm (single-ended input)
> 44k ohm (balanced input)

POWER CONSUMPTION
205W

DIMENSION
H=160mm, W=444mm, D=387mm

NET WEIGHT
24 kg /53 Pounds

 

 

(Russian)

(Click the photo to read the full review.)

 

 

"I’d always thought that reviewers who wrote about being able to 'hear the corners of a stage' were blowing smoke, but darned if the VS70.1 didn’t illuminate the corners of this sanctuary. I’m not sure how important that was to the music, but there it was." Vade Forrester of SoundStage. VS70.1 received the Reviewers' Choice award from SoundStage. (Click here to read the full review)

 

VS70 was an earlier version of VS70.1. It was reviewed by David Kan of 6moons. VS70 received the 6moons award.

(Click the icon to read the full review.)

 

VS70.1 received the Consumer Product Design, Certificate of Merits, from the Hong Kong Awards for Industries.