icon Audio
User Manual for:
Stereo 845 Integrated Amplifier
Shown with upgraded
“David Shaw” and Full Music driver valves
Contents
1 Final Inspection
2 Quick Set Up Guide
3 Connecting inputs & outputs
4 Getting the best performance
5 Trouble Shooting
6 Bias Adjustment
7 Valve Replacement
8 Specifications
9 Guarantee
10 Packing Instructions
11.Engineers Notes
About the Stereo 845
Thank you for purchasing our
ST 845
stereo
integrated amplifier using the wonderful RCA
developed 845 triode audio power valve.
YOU MUST READ AND UNDERSTAND THIS
MANUAL THOROUGHLY IN ORDER TO GET THE
BEST PERFORMANCE AND SAFE OPERATION.
If you are in a hurry to get your ST845 up and
running
go to Chapter 2 “Quick Set Up Guide”.
This will tell you the minimum amount of
information to get the amplifier working.
The ST845 pure valve amplifier is the result of years
of careful design and listening tests with a wide
range of speakers. Icon Audio amplifiers are hand
built
using
carefully
selected
audiophile
components. The transformers are hand wound
using low oxygen copper and special Japanese long
grain iron. Finally each amplifier is valved, carefully
commissioned and tweaked for best performance in
Leicester UK.
In order to get the best out of your amplifier, please
read the “SET UP” notes. These contain important
information about the correct operation and safety.
Should you be uncertain about anything please
contact your dealer or one of our team.
Valve amplifiers do need a little more attention than
their solid-state counterparts, but the sonic
improvements are well worth it. In this manual we
have tried to include everything that you need to
know. Please let us know if you find any errors or
feel that we have missed anything out.
The
ST 845
is a push-pull all triode integrated
amplifier using the 845 directly heated triode power
valve. These have very special characteristics which
many people consider give the finest reproduction of
any valves. Similar to but pre dating the Western
Electric 300B but with more power and punch.
These are employed in fixed-bias mode which gives
maximum power, cool running and low distortion.
You MUST occasionally check the bias (at least
twice a year), see chapter 6. The driver and phase
splitting is also done using vintage triode valves for
best sound quality. A Mullard GZ34 (US 5AR4)
valve rectifier is used for a controlled warm-up and
extra warmth. The pre-amplifier
circuit is a “passive”
design using a high quality ALPS pot along with gold
plated PTFE RCA input terminals and silver plated
high purity PTFE audio cable. This combination of
quality audiophile components, simplicity and time
honoured hand built construction is guaranteed to let
you bask in the warm glow of effortless music
reproduction, exactly as it should be.
IMPORTANT!
THIS MANUAL CONTAINS
ESSENTIAL HEALTH & SAFETY
INFORMATION FOR YOU AND
YOUR AMPLIFIER. PLEASE
READ & KEEP SAFE AND
REFER TO IF NECESSARY