
The AVI Laboratory Series Integrated
Amplifier
Owners Instruction Manual
For the use, care and maintenance of your Amplifier
AVI Ltd
Suite 7 Lightpill Mill
Bath Road Trading Estate
Stroud
Glos. GL5 3QF
Tel: 01453 752656
Fax: 01453 752777
info@avihifi.co.uk
www.avihifi.com

Introduction
Thank you for purchasing an AVI Laboratory series Integrated amplifier. As the
name implies it is a precision instrument, meticulously hand built and tested
and, given the right circumstances will produce the best sound quality that
technology will allow.
We recommend that before you attempt to use your new amplifier, you
carefully read the following instructions. An AVI Laboratory Series Integrated
amplifier will, under certain circumstances, produce as much current as an
electric arc welder! Therefore it pays to be absolutely sure everything is
correctly connected before you switch it on.
Installation
The amplifier can have other units of the same size stacked on top of it but it
should be in a well ventilated, and not unduly dusty environment. If you are
using an AVI amplifier with another manufacturers products that “plop or click”
on switch on, then they should be turned on first and allowed a few seconds to
stabilise before switching on the power amplifier. An amplified “plop or click”
can sometimes damage loudspeakers.
Use good quality, screened coaxial phono to phono leads to connect CD players,
tuners, record players, VCR and DVD players. The make is not important but
the quality is. Locking phono plugs are inadvisable as are unscreened
interconnects.
Loudspeaker cable runs are best kept below 10M and multi stranded conductors
running side by side are best. We use 1.5mm sq multi stranded copper cable
ourselves. Use good quality 4mm Banana plugs not spade lugs.
AVI amplifiers are designed to be largely immune from cable effects
provided the correct type is used.
AVI products are exceptionally reliable but many of the faults we deal with are
damaged phono sockets and speaker connections caused by people who are not
getting satisfactory results and believe changing cables may cure the problem.
This is extremely unlikely as the biggest differences you will hear are caused by
room differences and then ancillaries like CD players etc. If you are concerned
with the sound you are getting, please contact us and, provided you are able to
describe reasonably accurately what it is that you do not like, we will advise.

Loudspeaker Choice
Your Laboratory series Integrated amplifier is designed to drive speakers of
between 4 and 8 ohms nominal impedance, ones that are lower are not
suitable. These are extremely rare so it should not be a problem. The amplifier
is protected from short circuit or near short circuit damage and will shut down if
something is wrong. To reset it, switch it off at the mains for a few minutes and
then on again.
AVI has carefully designed the Pro-Nine-Plus and the Trios to go with our
amplifiers and we recommend that you thoroughly check them out before
deciding on another make. In many instances we find that people are buying
speakers that are not good enough to do justice to the Laboratory Series
Amplifier. The Pro-Nine-Plus is the best choice where there are space
constraints or our Trios where there is room and floor standing speakers are
preferred. If you are concerned, do contact us for advice. Buying loudspeakers
can be very difficult indeed. We will do our best to help.
Your Laboratory Series Integrated will drive and properly control a wider range
of two and three way speakers than most others. You have more choice and it
pays to take time to select ones that suit you best. There are enormous
differences in the sound of loudspeakers so be very careful, as expensive
mistakes are easy to make.
Remember that your amplifier is exceptionally powerful and quite capable of
damaging your loudspeakers if very high power levels are used with certain
types of Music. This high power provides a dramatic improvement in sound
quality over low powered amplifiers merely because clipping or limiting is
avoided, however loudspeakers are designed to handle low levels of power
continuously and instantaneous peaks or transients in music. Music that is
intended to sound loud like Dance or Garage is heavily compressed and may
cause damage to your speakers if very high volume settings are used for
prolonged periods. For most occasions, the level in question (depending on the
loudspeakers) would be uncomfortably high.
It is also important not to damage your loudspeakers with massive low
frequency peaks, typically kick drum type sounds. If these are very loud they
can drive the cone out of the magnetic gap or against the backplate of the
magnet assembly. The only remedy is a new bass drive unit.
Once you are ready to listen to your new amplifier, switch everything on as
described having first turned the volume down as far as it will go. Put in a CD
and then progressively increase the level until you reach a comfortable listening
level but a lower one than you would normally use.
It is very likely that your AVI Laboratory Series Integrated amp is much more
powerful and much cleaner sounding than you are used to, this will make it
sound less loud than a lower powered amplifier, however, some of the peaks in
the music will be much louder. Unless you allow for this, you may find the
sound uncomfortable. With much more care and patience than you would think
a volume control warranted, you would achieve quite startling results.