KR Audio VA900 Integrated Amplifier

By: Soundlabs Group  18-Jun-2012
Keywords: Electronics, Audio Equipment, Valves

This 80W stereo integrated amplifier is a microprocessor controlled hybrid system with low frequency power beam tetrodes in the output stage. The output tubes work in Class A/B (Push-Pull Ultra-linear with output transformer).

The condition of vacuum tubes is fully regulated by auto-biasing circuitry, so no extra adjustment for power devices is necessary. The circuit works with zero feedback. The output stage is powered by solid-state driver also working in class A with power MOSFET transistors. KR Audio VA900 stereo integrated amplifier rear panel. The amplifier has four identical stereo inputs which are switched by mechanical reed relays.

The level of the output signal is adjusted by a motorised ALPS potentiometer. The amplifier is also equipped with a remote control. All electronic parts are carefully selected and only the best quality components are used in the KR amplifiers. The covers on both the power supply and the output transformers are painted with a black composite material.

Power tubes are covered by a removable mesh metal protector housing. On the front panel there are four channel buttons with LED indicators, volume knob, IR-sensor for remote control, standby switch and status LED light. On the rear panel, you can find the mains switch, mains socket with integrated fuse, mains voltage selectors, 4x stereo RCA input connectors, 2x stereo speaker connectors and finally an output load impedance selector covered by a small metal deck which is fixed by a small screw.

KR Audio are famous for their high end hifi and being a tube manufacturer themselves, they certainly do know how a good amplifier should sound! Their flagship the Kronzilla KD has valves in the extreme; certainly the largest of any tube amplifiers at about 13 inches high!

The newly released VA900 has already been nicknamed the "Baby Kronzilla". All of the KR audio products are hand crafted, starting from the glass selection for the tubes right through to the metalwork. "Almost every showroom in France has a VA900 reference system" says CEO Dr Eunice Kron which attests to the early popularity of this amplifier.

Made in the Czech Republic, the unit is certainly very solid and well engineered. The four beautifully hand crafted valves are hidden securely behind a perforated removable metal grille. The main chassis is steel.

Specifications: Power Valves (Tubes): 4x KT120 (Made by KR Audio) Output Stage: Push-Pull Ultra-Linear Class AB1 Output Power: 2x 80 WRMS (THD=1%) Output Impedance: 4, 8 Ohms (Selectable) Frequency Response: 20Hz - 20kHz (-1dB) Driver stage: MOSFET Class A Remote Control: Volume, channel selector and stand-by Inputs: 4x line-in RCA (Cinch) Input Sensitivity: 0.75VRMS / 47kOhms (all channels) Power requirements: 230 /115VAC; 50/60 Hz (Suitable for 240V) Power consumption: 300VA (Approx.) Operating temperature: 5°C to 40°C Weight: 20kg (Approx.) Dimensions including projecting parts and controls (W x H x D): 38.5 x 24.5 x 41.5cm (Approx.) Supplied Accessories: Remote control Hex key wrench Manual Power cord Design and specifications are subject to change without notice.