Carlsbro 50 TOP EVOLUTION Manual

50 TOP Evolution Head
INTRODUCTION
Thank you for buying a Carlsbro product. Correctly used it will provide years of reliable service, and deliver
great tone and performance. Please read this user guide thoroughly in order to safeguard your equipment, and
obtain maximum performance from it.
UNPACKING AND INSPECTION
Carefully unpack the unit. If it appears damaged in any way, return it to the dealer it was purchased from in its
original packaging. Carlsbro Electronics Ltd cannot accept any responsibility for damage arising from the use
of non-approved packaging.
WARNING ~ IMPORTANT SAFETY INSTRUCTIONS
1. Avoid excessive heat, humidity, dust & vibration. NEVER use the amplifier in damp or wet conditions.
Do not place liquid filled containers on the amplifier. Do not use anywhere with dripping or splashing
liquids.
2. This product contains no user-serviceable parts. Refer all repairs to qualified Carlsbro service
personnel. Opening this product & tampering with the internal circuitry voids the warranty.
3. Always ensure that a good quality mains lead is used applicable for your country. The following wiring
convention is used in all Carlsbro product mains leads, and must be strictly observed: Green & Yellow
= Earth. Brown = Live. Blue = Neutral. . IMPORTANT: THIS UNIT MUST BE EARTHED!
4. If the mains fuse needs replacing, DISCONNECT THE AMPLIFIER FROM THE MAINS SUPPLY. The
fuse is below the mains IEC socket, and must be replaced with a fuse of the type and rating stated on
the rear panel. If a replacement fuse fails immediately, contact your local service agent. DO NOT
replace with a higher value.
5. This amplifier is capable of very high sound pressure levels. Prolonged exposure to may cause hearing
damage. Take appropriate steps to minimize your noise exposure.
6. Ensure the mains isolation switch is readily accessible when the amp is in use.
GENERAL GUIDELINES FOR USE.
1. Always turn the volume to zero when switching on or off. This helps protect the speaker, and also your
ears.
2. Start with the tone controls set to “12 O’clock”, and then alter them up and down to appreciate their
range and area of influence on your sound.
3. Ensure you use good quality screened audio cables for connecting instruments, mic’s and effects to
your equipment.
4. Experiment with the input gain and volume levels to obtain the overall level and tone you require, whilst
retaining clarity and definition. ‘All on 10’ may not give the best results!

PRODUCT DESCRIPTION
The 50 TOP Evolution valve head has been designed and voiced to give the best performance for
electric guitar. It is a fully featured professional standard valve amplifier, equally suited to live and studio work.
It is complemented perfectly by Carlsbro’s ‘Classic 412’ cabinet, but can be used with any appropriate 8, 16 or
pair of 16 ohm cabinets.
MAIN FEATURES
• Two Channels (Clean and Drive) selected by front panel or footswitch
• Independent variable input gain for each channel
• Variable channel level (Drive channel)
• Gain Boost (Drive channel) selected by front panel or footswitch
• Powerful three band EQ
• Dual foot switchable Master volumes
• Triode/Pentode switch (half power setting)
• ‘Sleep’ mode auto muting
• Series/parallel switchable FX loop (capable of remote activation by footswitch)
• 2 x EL34 power valves in Class A/B for 50W of great British valve tone
• 4 x ECC83 preamp valves
FRONT PANEL LAYOUT
1. Input. Connect your guitar here using a high quality screened audio cable.
2. Volume. This control sets the gain and level of the clean channel (Channel 1). Used in conjunction with
the master volume controls you can achieve a wide range of tones at all levels. To get the best clean
tone, turn this control fully anticlockwise and the master volume fully clockwise. Adjust this control
upward until the desired level is achieved. For a classic vintage overdriven tone, turn this control up full
and control the level with the master volume.
3. Channel switch. Used to switch between Channels 1 and 2. When depressed, channel 2 is selected
and the yellow LED will illuminate. NOTE; When using the footswitch, this switch must be ‘in’.
4. Gain. This control sets the gain at the input (the inputs electrical signal strength) for the Drive channel.
Increasing the gain will increase the level of overdrive, or distortion in the tone.
5. Boost. Depressing this switch boosts the amount of gain available. With this switch depressed, the
function can be controlled by footswitch from the rear panel.
6. Level. This sets the output level of the drive channel, to allow it to be balanced with the clean channel.
7. Bass. This is used to control the level of bass or low frequency sound. Turning the control anticlockwise
will progressively decrease the level of bass.
8. Mid. This works the same way as the Bass control, but affects mid range frequencies.
9. Treble. This works the same way as the Bass control, but affects Treble or high frequencies.
Experiment with these controls whilst playing to appreciate the tonal variation possible from your amp
10. Master Volume I. Together with Master Volume II these control the overall volume or sound level from
the amp. They can be selected by footswitch, allowing two different levels to be set, for example to
allow a level boost for a solo.

11. Master Volume II. See Master Volume I (item 10) above
12. ‘On’ Light. This red jewel light illuminates when the unit is supplied with the correct mains voltage and
switched on. When switched off, the light will slowly extinguish.
13. Standby. When switched to ‘On’ the amp is active and can be used. When switched to off, the valve
heaters are on, but the signal path is inactive. This should be switched to ‘Off’ when the amp is first
turned on, and switched to ‘On’ after the valves have warmed up (approximately 1 minute). This will
help prolong the life of your valves.
14. Main Power Switch. Turning this ‘Off’ disconnects the amplifier circuit from the mains voltage.
Rear Panel Layout
1. IEC Input socket. Connect the supplied mains lead here. The mains fuse is also located below this
socket. Replace the fuse only with the same type and rating stated on the rear panel. If a replacement
fuse fails immediately, contact your local service agent. DO NOT replace with a higher value.
2. HT Fuse
3. Bias Adjust and Test Points. These enable a competent engineer to easily adjust the bias for the power
valves. Connecting a meter between TP1 and TP0 allows the bias voltage to be measured for valve 1,
and between TP0 and TP2 allows the bias voltage to be measured for valve 2. Contact the Carlsbro
service dept for detailed instructions on biasing of valves
Note: We recommend that a qualified electronic technician, using suitable test equipment, performs installation
of valves and valve biasing. Incorrect adjustment of valve bias can shorten valve life, degrade tone and
performance and lead to amplifier damage.
4. Triode/Pentode (‘half power’) switch. This selects the mode the power valves operate in. Pentode
mode will give the full 50W output, whilst Triode mode will give 25W output, with a slightly different
tone.
5. Speaker Outputs. This amp has 3 speaker outputs: one for a 16 ohm load (i.e. one 16 ohm cabinet),
and two for an 8 ohm load (i.e. one 8 ohm or two 16 ohm cabinets). DO NOT combine the 8 and 16
ohm output sections. Make sure you use the correct impedance load.
6. Footswitch sockets. Connect any suitable 2 way footswitch with a stereo jack lead to socket 1 to switch
channels and master volumes, or to socket 2 to switch boost and effects loop on/off. These sockets
can be connected to two separate 2-way switches, or the Carlsbro 4-way footswitch (AC1182). Note:
the front panel switches for channel and boost must be ‘in’ for the footswitch to operate.
7. Series/Parallel Switch. This selects whether the effects loop works in parallel with the amp signal chain
(i.e. final output is a mix of ‘dry’ direct and ‘wet’ effected signal) or in series (i.e. all signal passes
through the effects, and final output is all ‘wet’ effected signal.
8. Send & Return Sockets (FX Loop). Use these to connect external effects units, or to send the preamps
output to another amp. Note that this loop is inactive and not connected to the signal path until a jack
plug is inserted into the return socket.
NOTE: ALWAYS DISCONNECT THE UNIT FROM THE MAINS BEFORE REPLACING THE FUSE.

VALVE REPLACEMENT
To replace any of the valves in this amp, first disconnect the unit from the mains supply, then remove
the rear panel of the head by removing the screws. The valve retainers can then be taken off by hand, and the
valves removed by pulling vertically upward away from the socket (Caution: If the amp has recently been used
these may be hot). This amp uses ECC83 / 12AX7 preamp valves (4) and EL34 power valves (2). The power
valve biasing should be set by a qualified amp technician after replacement to ensure best performance and
valve longevity. Carlsbro recommend using matched pairs of power valves, and replacing the power valves
together to ensure best performance and longevity.
TECHNICAL SPECIFICATIONS
Power Consumption : 220VA max
Power Output : 50W RMS (25W in triode mode) into 8 or 16 ohm
Height : 266mm
Width : 647mm
Depth : 235mm
Weight : 18kg
Carlsbro Electronics Limited constantly seek ways to enhance our products, and improvements take
place continually. Whilst every effort is made to produce up to date literature, Carlsbro Electronics limited
reserve the right to alter specifications without prior notice.
GENERAL INFORMATION
The unit is factory set for the nominal mains voltage specified on its rear panel, and should be used
with the mains lead supplied.
For 230V the working range is 207 – 253V, 50 – 60 Hz AC
For 115V the working range is 104 – 126V, 50 – 60 Hz AC
SERVICE
All Carlsbro products are thoroughly examined and tested before leaving the factory, and if correctly
used will give many years of excellent service. However, if a problem arises, proceed as follows:
a) Contact the dealer from whom the unit was purchased and describe the symptoms of the fault.
b) If the dealer cannot help, return the equipment to the national distributor for your country. Use
the original packaging to protect the equipment from damage. Include a note with the
equipment stating your name and address, details of the problem, serial number and date and
place of purchase.
The unit does not contain any user serviceable parts. For details of spares, accessories and other Carlsbro
products, contact your local dealer. In the event of any difficulty contact our sales office at the address below.
COMPLIANCE
This equipment is designed to comply with the following standards:
EN55103-1:1996
EN55103-2:1997
EN60065:2002
Carlsbro Electronics Limited
Cross Drive, Kirkby in Ashfield, Nottinghamshire, NG17 7LD, England.
Tel: [phone] Fax: [phone]
E-mail sales: [email protected] http://www.carlsbro.com