Carot One FABRIZIOLO User manual

- 3 -
1. Introduction
Thank you for your purchase of Carot One FABRIZIOLO Audiophile Stereo
Tube Preamplifier.
Carot One introduces the mini-size audiophile stereo preamplifier
FABRIZIOLO providing high quality amplification of your audio source. Our
special techniques in circuit design and component selection, FABRIZIOLO
achieves the sound quality of high-end Hi Fi but in a very affordable price.
2. Features
Compact design (mini-size & light weight), easy portable and setup
An AC adaptor is bundled for continuous power supply.
Separated preamplifier & AC adaptor design to minimize mutual
interference and flexible to apply other power sources, e.g. lead-acid
battery.
Standard audio and speaker sockets compatible with most audiophile
quality cables.
Audiophile-graded parts and components
The stylish & specially-plated aluminum case provides not only
good-looking, and also provides outstanding shielding capability.

- 4 -
Safety Guidelines
Important safety instructions
This product is designed and manufactured to meet strict quality and safety
standards. However, you should be aware of the following installation and
operation precautions.
1. Take heed of warnings and instructions
You should read all the safety and operating instructions before operating this
equipment. Retain this handbook for future reference and adhere to all
warnings in the handbook or on the equipment.
2. Water and moisture
The presence of electricity near water can be dangerous.
Do not uses the equipment near water, for example next to a bathtub,
washbowl, kitchen sink, in a wet basement or near a swimming pool, etc.
3. Object or liquid entry
Take care that objects do not fall and liquids are not spilled into the enclosure
through any openings. Liquid filled objects such as vases should not be placed
on the equipment.
4. Placing the equipment
Only use a rack or shelf that is stable and strong enough to support the weight
of this equipment.
5. Ventilation
Do not place the equipment on a bed, sofa, rug or similar soft surface, or in an
enclosed bookcase or cabinet, since ventilation may be impeded. We
recommend a minimum distance of 50mm around the sides and top of the
equipment to provide adequate ventilation.
6 Heat
Locate the equipment away from naked flames or heat producing appliances
such as radiators, stoves or other appliances that produce heat.

- 5 -
7 Climate
The equipment has been designed for use in moderate climates and in
domestic situations.
8. Cleaning
Unplug the unit from the mains supply before cleaning.
The case should normally only require a wipe with a soft, lint-free cloth. Do not
use chemical solvents for cleaning.
We do not advise the use of furniture cleaning sprays or polishes as they can
cause indelible white marks.
9. Power sources
Only connect the equipment to a power supply of the type described in the
operating instructions or as marked on the equipment.
The primary method of isolating unit from the mains supply is to use the switch
on the rear of the unit. The equipment must be installed in a manner that
makes disconnection possible.
10. Power-cord protection
Power supply cords should be routed so that they are not likely to be walked
on or pinched by items placed upon or against them. Pay particular attention to
the point where they exit from the equipment.
11. Power lines
Locate any outdoor antenna/aerial away from power lines.
12. Non-use periods
If the equipment is not being used for an extended period, we recommend that
you unplug the power cord of the equipment from the outlet, to save power.
13. Abnormal smell
If an abnormal smell or smoke is detected from the equipment, turn the power
off immediately and unplug the equipment from the wall outlet. Contact your
dealer and do not reconnect the equipment.
14. Servicing
You should not attempt to service the equipment.
Contact your dealer to arrange servicing.

- 6 -
15. Damage requiring service
The equipment should be serviced by qualified service personnel when:
A. the power-supply cord or the plug has been damaged, or
B. objects have fallen, or liquid has spilled into the equipment, or
C. the equipment has been exposed to rain, or
D. the equipment does not appear to operate normally or exhibits a marked
change in performance, or
E. the equipment has been dropped or the enclosure damaged.
Safety compliance
This equipment has been designed to meet the EOCENE 60065 international
electrical safety standards.
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) This device may not cause harmful interference, and
(2) This device must accept any interference received, including interference
that may cause undesired operation.
WARNING:
Due to the mains switch being located on the rear panel, the apparatus must
be located in an open area without anything obstructing access to the mains
switch.
Mains plug/appliance coupler is used to disconnect device and it shall remain
readily operable.
Correct disposal of this product
This marking indicates that this product should not be disposed with other
household waste throughout the EU.
To prevent possible harm to the environment or human health from
uncontrolled waste disposal and to conserve material resources, this product
should be recycled responsibly.
To dispose of your product, please use your local return and collection systems
or contact the retailer where the product was purchased.

- 7 -
3. Overview
1. Volume Controller and Pre-Amp Power On/Off.
2. 3.5mm AUX input socket for MP3, etc. (over-ride rear input)
3. 3.5mm Headphone socket
WARNING:
When plug in your headphone or MP3 into the mini jack (2 and 3), always
plug in a vertical way. NEVER shake the mini jack as this will
permanently damage the internal structure of the socket causing bad
contact of signal.

- 8 -
4. Power Supply Socket; Plug the bundled AC Adaptor to this socket to
supply power to this amplifier.
5. Audio signal line output.
6. Audio input. The audio signal input (LEFT/RIGHT) connects from
audio source (e.g. CD player) to the amplifier by the RCAaudio cable.
7. Vacuum Tube (6922)
WARNING:
When plug in the supplied mini jack cable between 5, always plug in a
vertical way. NEVER shake the mini jack as this will permanently
damage the internal structure of the socket causing bad contact of signal.

- 9 -
3.1 Connection
FABRIZIOLO is easy to use product. Simply connect your source (CD player,
MP3 player, etc..) and amplifier / headphone following below steps, you can
enjoy the high quality music in a second:
-Connect “Line Out” mini socket (5) to the “Line In” of your amplifier using
the supplied mini jack to RCAaudio cable.
-Connect your CD player to the “Line In” RCA socket (6) using normal RCA
audio cable (not included)
-You can also connect your MP3 player to the 3.5mm AUX input socket (3)
using the included mini jack cable. Once this input is used, it will over-ride
the rear RCAinput (6).
-You can connect your headphone to the headphone socket (9). Once this
output is used, it will over-ride the rear “Line Out” socket (5)
-Connect the power adaptor to the “Power In” connector (8).
It’s now all set and you are ready to enjoy your music.
3.2 Operation
Please follow the below steps such that you can enjoy the product without any
difficulty:
-Turn the “Volume controller” (1) clockwise to turn on the pre-amplifier and
keep the level at minimum. Now the vacuum tube (11) will slowly turn
on and you will see blue light from the top window. Wait for around 15
seconds to let the vacuum tube warm up to its operation temperature.
-Play your source equipment and you can hear music from your speakers.
Now, you can control the volume level by turning the “Volume controller” (1)
-There is a “3.5mm Headphone socket” (2) in the front panel. You can
connect your headphone to the unit. Once your headphone is connected,
the rear output will be disconnected automatically.
-To turn off the amplifier, turn the “Volume controller” (1) to minimum level.
Then, switch off your power amplifier. Now, turn the “Volume controller” (1)
to fully turn off the pre-amplifier.

- 10 -
4. Specifications
4.1 Specification of the HeadphoneAmplifier Unit
Signal-to-Noise Ratio (SNR) 92dB
Power Output 3.0 Watts per channel on 33 Ohm
Headphone
Frequency response 15 Hz - 100 kHz -1db
Input Impedance 10k Ohms
Input Audio CD IN RCA(Left/Right) x 1 [3Vpp max.]
4.2 Specification of the Pre Amplifier Unit
Vacuum Tube 6DJ8/6922 series or 12AU7 series
(exchangeable)
Signal-to-Noise Ratio (SNR) 92dB
THD + Noise 0.05% @ 10k ohm 0.15% @ 33 ohm
Input Audio CD IN RCA(Left/Right) x 1 [3Vpp max.]
Power Socket (5.5mm/2.1mm) x 1
Output Audio OUT 3.5mm x 1
Headphone OUT (3.5mm) x 1
Knob Audio and power switch x 1
Power Indicator (Blue LED under Tube Socket) x1
Volume Knob x 1
Power Supply DC 12V-13V (max.)
Dimensions (W)76mm x (H)60mm x (D)100mm

- 11 -
4.3 Specification of the AC Adaptor
AC Input UniversalAC 100V-240V/50-60Hz
DC Output DC 12V 3.5A (42W)
DC Plug DC 2.1mm
Ripple & Noise <= 25mV
Over-load Protection 105%-150%
Over-voltage Protection 115%-150%
Dimensions (L)78mm x (W)50mm x (H)33mm

- 12 -
5. Technical Notes (for professional user only)
Carot One has already pre-set the jumpers and fine-tuned the DC bias voltage
of each FABRIZIOLO with the packaged vacuum tube before shipping.
However, changing different tubes to taste for different sound is the great fun
for many audiophiles and also a great feature of FABRIZIOLO.
There are some important notes should be aware before changing tubes.
FABRIZIOLO supports two major tube series:
(1) 6DJ8, 6922, 6N11, 6H23n, ECC88, E88CC, etc., and
(2) 12AU7, 5963, 5814, ECC82, etc.
If you change the tube within the same series, it needs to re-tune the DC bias
voltages ONLY.
If you change the tube from another series, it needs both to re-tune the DC
bias voltages and re-set the jumpers. Otherwise, the tube may be burnt out.
(Remember to power OFF the machine before setting)

- 13 -
5.1 DC Bias Voltage Tuning
Since each tube might derivate a bit in parameters, especially from different
series, it needs to re-tune the DC bias voltages to guarantee the machine is
working in the best point and performing the best sound quality.
There are two blue precise adjustable potentiometers (P1, P2) for tuning the
DC bias voltage of each channel. The DC bias has been tuned in factory. But
after run-in for a period or changed another tube, it would be deviated that the
fine-tuning is needed.
Before you tune these, you need a screwdriver (take off the case), a small
screwdriver. (Turn the screw of the potentiometer) and a (digital) multi-meter
to detect the DC bias voltage:
1. Use screwdriver to take out the two upper level screws in the front panel &
another two screws in the back panel. Then, open the upper case.
2. Power ON the machine with no audio signal input.
3. Wait at least 5 minutes for the machine to run in.
4. Use the multi-meter to detect the DC voltage between the test point A (L)
[red] in the PCB & the GND [black] (e.g. the ring of the power switch or the
outer ring of those RCAsockets) of the LEFT channel.
5. Turn the screw on the top of the P1 potentiometer by a small screwdriver
clockwise or anticlockwise until the voltage as close as to +6~+8V.
6. Then, repeat step 4 and 5 for the RIGHT channel by changing the test point
to A (R) [red] and turning the screw on the top of the P2 potentiometer.
7. Power OFF the amplifier.
8. Cover back the upper case and tighten the screws.

- 14 -
6. Troubleshooting
If your machine is out of order, it may not be very serious. Before you call your
local distributor or us to repair, you are suggested to check the following:
SYMPTOM POSSIBLE CAUSE REMEDY
cannot power ON
indicator not bright power cords not properly connected properly connect the power cords
power switch is OFF switch ON the power
no sound at all the volume level is too low turn volume level higher
The audio cable not
properly connected properly connect the audio cable
the audio source (e.g. CD
player) not started playing start playing the audio source
Hum tube not fully pushed in Insert Tube securely
audio connector plug not
fully pushed in Insert plug securely
incorrect input switch
position check the corresponding input switch
sound out(s) loose connection check input and output
connections. When all has
been double-checked
reduce volume and switch
unit back on

- 15 -
7. Accessories
. 3.5MM jumper cable x 1
. 3.5MM to RCA jumper cable x 1
. Tube x1
. +12V power supply x 1
. User Guide x 1
OPENITEM ITALIA is WORLDWIDE DISTRIBUTOR of Carot One
Website: www.carotone.it
Email: [email protected] - END -