discrete class A
non eddy current RCAs
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Review in HiFi+ Issue 26. The Bonnec phono stage up
against the well known reference from Pass Labs (a second more detailed
review in HiFi+ Issue 34) and Bonnec Fono up against Mark Levinson
No.25s (German magazine Hörerlebnis 55). Please have a look at the
quotes on our web site at REVIEWS.
The BONNEC FONO pre pre-amplifier is built to the highest possible
standard and contains over 700 hand-assembled and hand-soldered
components. All the amplifier stages are designed to achieve very high
linearity. The FONO uses more than 60 discrete transistors of the
highest grade with a circuit design that combines the advantages of
transistors with the advantages of valve circuit technology.
Care has
been taken to ensure that as few as possible of the components are
actually located in the signal path. Most of the components being there
to support the signal during its passage through the amp, this support
uses more components than in any other phono pre pre-amplifier that we
have come across.
The two MM and MC inputs of the amp allow the option to vary cartridge
loading and gain.
This ensures correct matching with the widest range
of cartridges.
The performance of any pre pre-amplifier is greatly influenced by the
number and quality of its power supplies. To this end great care has
been taken to ensure that at every stage of the signal path has its own
local, very low noise Double Power Supply.
On the FONO pre-amplifier
there are two separate transformers; one for the MC input stage alone.
These in turn supply 18 separate power supplies located at strategic
points throughout the circuit path.
Rediscover your record collection.
- Technical details:
Amplification
- non
feedback, discrete class A ZETEX input stage. We have chosen
SMD-transistor-cases for better thermal stability – more open and three
dimensional sound
- The
gain varies automatically with frequency depending on RIAA, to keep the
sound of the stage on the highest level for all frequencies
- Discrete
audio circuits with as
few as possible of the components actually located in the signal path and
a design that will also handle the most complex music signals
- Semi-active RIAA network – better dynamics
- Field optimized circuit board layout – fast sound
- Perfect components – like silver/gold foil
capacitors
- Input impedance and capacity adjustable on the
back panel by rotary switches
- Correct input value can also be soldered to the board
- Gain: adjusted by solder values – more detailed
sound
- The audio circuits have local voltage regulation
- DPS design – and special audio grade electrolytic capacitors
- All electrolytic capacitors are special audio
grade types
- Non eddy current RCA connectors from JALCO
Power Supply
- Dual
Power Supply DPS circuit design
- 2 Low
noise audio grade toroidal transformers enclosed by a magnetic screened
internal extra case
- High
speed soft recovery rectifier diodes
- Non
choke power supply, instead the transformer is designed as a choke – much
better dynamics
- Matched
special audio grade main capacitors
- The
case is made from very high quality 3mm aluminium, brushed and anodized
- Three
point mounted circuit boards
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