AVI called their multi-award winning integrated amplifier the Laboratory Series because it is a development (albeit a meticulous and painstaking one) of the amplifiers they use to evaluate their loudspeakers. It is particularly important that an amplifier being used for such a purpose is immune to the effects of the speaker, has negligible distortion and sufficient dynamic range to avoid clipping on the transients in music. Designers want to hear how their speaker designs reproduce the music, not an inadequate amplifier!

The Lab Series Integrated Amp has six inputs, the S21MI version being equipped with all line level inputs, while the S21MI+P has a MM/MC phono stage (more about this later) and five line level inputs..  The tape loop is buffered and it allows you to record one source while listening to another.  Volume control is by a large bead blasted aluminum knob (to provide the correct feel) and the front panel has accurate graduations to ensure precise setting.  When controlled by the remote handset, a dab of the button will produce changes of approximately 1dB.

Power output into 8 ohms is a conservatively rated 200 WPC and this almost doubles into 4 and 2 ohms.  Enormous current is available ensuring that the largest and most complex speakers are driven with ease, and that low frequency control and dynamics are displayed to perfection.  If the amp is overheated or the outputs are shorted the fast acting protection circuitry will interrupt playback.  The output stage protection will also engage if the load drops to a little over 1 ohm.

With the Lab Series Integrated Amp powered up and running, the most sensitive ear applied to the most sensitive loudspeaker may just be able to hear background noise.  Total Harmonic and Intermodulation Distortion is lost in the noise generated by most test equipment!

This is one of the finest sounding amplifiers you are going to hear, regardless of your budget!

AVI is for serious music enthusiasts!  For many this means they must still be able to play irreplaceable vinyl, and play it to the highest standard that technology permits!  AVI have designed a factory installed phono stage that is switchable (via a switch in the rear panel) to either moving coil or moving magnet cartridges.  This internal phono stage has been favorably compared to separate phono preamps costing as much as the Lab Series Integrated itself - quite an achievement for a $300.00 option.

The Laboratory Series Integrated Amplifier is much larger and heavier than its predecessors.  It is built from large chunks of milled aluminum and thick steel sheet to ensure mechanical rigidity and absolute integrity of construction.  The huge heat sinks are anodized in black as is the front panel and top cover. The controls and the graphics are in contrasting silver.

AVI has chosen very high performance bi-polar output devices. They have a 50MHz power bandwidth!  Although they are more difficult to use, it is generally agreed that they sound a little more "musical" than MOSFETs.  Experience has shown that the slightest imperfections of sound, once noticed, become major irritants and quickly alienate listeners. AVI’s reputation for outstanding sound quality is very precious to them and they have taken extreme measures to ensure that no such defects are present in any of their products.

The Laboratory series Integrated amplifier was designed to compliment the entire range of AVI products, and was intended from the outset to form the basis of an entirely new range of High End Laboratory Series electronics.

"The biggest single upgrade I’ve ever made to a Hi Fi system"

"I have to say that the AVI integrated amplifier is the most exciting Hi Fi product I’ve ever had the pleasure to use"

"The is only the second product in 35 years in audio that has really impressed me, the last time it was the Spendor BC1’s"