New power supply technology
The 725's totally redesigned power supply unit works even more precise and regulates more precise and faster than the power supply of the 720. With more than 500'000 µFarad of storage capacitance it provides almost unlimited impulse current for the analog circuits.

Reddot Design award
In 2006 the timeless design of the soulution Series7 products has been rewarded with the famous and coveted reddot design award. The international jury was especially impressed by its plain and unobtrusive design that does not show any visible cooling fins or screw connectors... reddot

Philosophy

A perfect preamplifier shows consistent level and phase performance regardless of load. At soulution we stick to this ideal without resorting to often-used compromises like high amplification with high negative feedback. The result: virtually no distortion, hum or noise, maximum channel separation and impressive bandwidth (up to 1MHz/-3dB).

Design

As few components in the signal path as possible and a dual-mono layout with discrete left and right channels maximise audio purity and virtually eliminate crosstalk. Input selection (including the ground connection) is by high-grade relay. And input buffering ensures the 725 presents a benign load to source components.
Input levelling permits different source device levels to be accommodated. All inputs are monitored continually for residual DC with audiophile-grade blocking capacitors automatically switching in and out when required. In this way maximum operational safety is guaranteed. As a further safeguard the front panel display indicates when DC is present.

Volume control

The volume control uses high-precision, low-noise metal foil resistors, and controls both volume and balance. To block switching peaks during volume changes which may be hazardous to power amplifiers a second volume control with PGA (Programmable Gain Amplifier) is used. Active only when the volume is changed, it is similar to a potentiometer and enables the volume to be adjusted in smooth steps without clicks. As soon as the new desired level has been selected, the unit returns control to the precision resistors.

Phono MC preamp optional

Designing and building the ideal phono stage is an exacting challenge. It must provide up to 80dB gain - equivalent to raising the signal level by 10,000 - yet must exhibit level and phase true behaviour while adhering strictly to RIAA-IEC equalisation standards. In the 725 this goal is realised with an ultra wideband (1MHz/-3dB) multi-stage amplifier built around the very highest quality components.

Power supply

Key to a good sounding amplifier is a stable, noise-free power supply - especially for the audio stages. The 725 is equipped with two dedicated power supplies: one for the audio stages and one for the digital circuits. For powering the audio stages an innovative, amplifier-like circuit design is used, providing an extremely stable supply voltage. The 725's totally redesigned analog power supply unit works even more precise and regulates more precise and faster than the power supply of the 720.

With more than 500'000 µFarad of storage capacitance it provides almost unlimited impulse current for the analog circuits. Bus bars supply this power throughout the unit without loss. A unique concept in the audio world, this allows the same high quality supply to be delivered to all parts of the 725.

Operation

Operation of the 725 is through three buttons and a rotary control on the front panel. All operating modes are indicated on the clear display. Additionally there are many other functions which can be used to optimise and match an entire audio system around different components.

Eingänge
2 x Symmetrisch (XLR)
3 x Unsymmetrisch (RCA)
1 x Phono (RCA)

Ausgänge
1 x Symmetrisch (XLR)
1 x Unsymmetrisch (RCA)

Specifications

Power rating

Power consumption (ON): 60 W
Power consumption (OFF): <0.5 W

Line-inputs (IN1/2, IN 4...6)

Voltag gain

balanced: +9.5...+18.5 dB
unbalanced: +3.5...+12.5 dB

Frequency response: DC...1 MHz
Slew rate: 400 ns
Distortions (THD+N) @ 1kHz: <0.0006 %
Signal-to-Noise-Ratio (SNR) @ 1kHz: 130 dB
Corsstalk @ 1kHz: 105 dB

Impedance

balanced: 2 kΩ
unbalanced: 47 kΩ

Phono-input (IN3, optional)

Voltage gain: +54...+60 dB
Amplification bandwith (internal): DC...1 MHz
Slew rate: 400 ns
Distortions (THD+N) @ 1kHz: <0.0006 %
Impedance adjustable: 10 – 1.000 Ω

Ouput

Voltage max. rating

balanced: 16 Vrms
unbalanced: 8 Vrms

Current max. rating: 1 A

Impedance

balanced: 2 Ω

unbalanced: 2 Ω
LINK: 12 V

Dimensions

Lenght x Width x Height: 480x450x167 mm

Weight: 30 kg