Mad Professor Old School 51RT User manual

MAD PROFESSOR OLD SCHOOL 51RT MANUAL
Thank you for buying the Mad Professor Old School 51RT guitar amplifier.
As the name applies this amplifier is designed for classic guitar tones from the 50’s to
modern times. You are able to get legendary tones from both side the Atlantic that suit
country, pop, rock, reggae, soul, hard rock, alternative and every other style-name the
clever marketing people at record companies come out with.
No need for channel switching as these classic tones from clean to distorted are easy to
get by adjusting your guitar’s volume and tone knobs.
Coming from a pedal manufacturing company this amp takes pedals VERY well.
The amp has build in Reverb and Tremolo for the final old school touch.
With good care this amplifier will give you decades of trouble free operation.
Do not try to open the amplifier chassis – there are no serviceable parts. Only a qualified
service technician should remove the chassis.
Do not expose the amplifier to rain, moisture, or any kind of liquids. Never use the amplifier
in wet or damp conditions.
TUBES ARE HOT. DO NOT TOUCH DURING OR SHORT AFTER OPERATION.
Plug the amp only to correct AC voltage, the voltage can be changed to 100/ 120 or
230/240V from the back panel of the amp. The fuses must be changed to correct rating if
voltage is changed.
The fuses should be replaced only with identical ratings and only when the power cord has
been disconnected from its power source.
Never plug the amp into an ungrounded outlet.

Tube replacement and amp biasing can be done ONLY by a qualified service technician.
Vacuum tube amplifiers generate heat. Insure proper ventilation. Keep away from curtains
or any flammable objects. Do not block ventilation.
This guitar amplifier can produce high volume levels. Exposure to high volume levels may
cause hearing damage!
Protect the amp from physical knocks or bumps especially when the tubes are hot. Let the
amp cool down after use before you move it.
Never operate the amplifier without a connected speaker.
Use high quality cables only, instrument cable between guitar and amplifier and speaker
cable between amp and a speaker.
Don’t take any risks, if there are any doubts, consult your dealer and/or a qualified
technician.
USE:
• Connect the amplifier power cord to correct value grounded power outlet. Check
that the Voltage Switch value matches the available voltage.
• Make sure the speaker is connected to the amplifier. Never operate the amplifier
without a speaker or a load connected to the amplifier.
• Plug your guitar (using a high quality cable) in to the input
• Switch the Power to mid position (Stand by) and wait about 30 seconds to let the
tubes warm up.
• Then switch the amp on (switch down position)
• Now the amplifier is ready to use.
• You need to turn up both Volume and Master volume to get a sound from the
amplifier.
Basic settings:
Bright American clean: Voicing Switch down. Turn the master volume to 2 o’clock,
bass and treble to 12 o’clock, Middle to 10 o’clock. Presence to 2 o’clock. Turn up
the volume until the tone start to distort (depending on pickup at about 10 o’clock).
Fine-tune to your taste with the tone knobs.
Warm British clean: Voicing Switch down. Turn the master volume to 2 o’clock,
bass and middle to 12 o’clock, and treble to 12 o’clock. Presence to 2 o’clock and
turn up the volume until the tone starts to distort (depending on pickup at about 10
o’clock). Fine-tune to your taste with the tone knobs.

Crunch tone: Voicing Switch down. Turn the master volume to 12 o’clock, bass and
treble to 12 o’clock, Middle to 11 o’clock. Presence to 2 o’clock. Turn up the volume
to about 2 o’clock. Fine-tune to your taste with the tone knobs
Distorted tone: Voicing Switch up. Turn the master volume to 12 o’clock, the Gain
to 1 o’clock, bass, middle, treble and to 12 o’clock and Presence to 2 o’clock .
Set the output volume with Master Volume. Fine-tune to your taste with the tone
knobs.
Lead tone: Voicing Switch up. Turn the master volume to 12 o’clock, the Gain to 3
o’clock, bass to 11 o’clock, middle 12 o’clock, treble 11 o’clock and Presence to 2
o’clock .
Set the output volume with Master Volume. Fine-tune to your taste with the tone
knobs.
FRONT PANEL:
1. Input: 1⁄4” unbalanced input. Plug your guitar cable in here.
2. Gain: Sets the gain of the preamp, higher settings will produce distortion
3. Voicing: Lower position for classic lower gain tones. Upper position for fatter
more modern higher gain tones. The switch increases gain but also effects
frequency response. The lower position will have less low-mids and more
treble and the higher position has more low-mids and a little less treble.
4. Treble: Adjust the treble response of the amp, this adjusts just the treble, it
does not affect the bass response as with many vintage amplifiers
5. Middle: Tuned control for middle frequency
6. Bass: Adjusts the amount of low end
7. Presence: Turning up adds presence for brighter tone
8. Reverb: adjust the amount of the build in classic reverb. If the foot switch is not
plugged in, the reverb is active.

9. Tremolo Speed: adjust the speed of the build in classic Tremolo effect. If the
foot switch is not plugged in, the Tremolo is active.
10. Tremolo Depth: adjust the depth of the build in classic Tremolo effect. If the
foot switch is not plugged in, the Tremolo is active. By turning down this
knob, you’ll turn off the tremolo.
11. Master Volume: Adjust the volume of the amplifier. Adjusting this you can get
overdriven sounds at any volume level. With heavily distorted tone it helps
with the hum if you turn down the Master Volume a bit, lowering the Master
Volume will also tighten the distorted tone.
12. Power/Standby switch: This switch works as an AC power on/off switch and
as a Standby switch. Up position power is off, mid position is Standby and it
mutes the power amp, down the amp is on.
Use the Standby position to warm the tubes before you turn the amps on. 30
seconds after switching the power on is enough, after that you can turn the
amp on. You can also mute the amp for short breaks or when switching
guitars.
BACK PANEL:
13. Mains voltage selector switch:
Switch the voltage to match the AC power you are using.
To change the voltage first turn the amp off and disconnect the power cable. Then
slide the switch to the correct position and change the mains fuse to correct value.
14. Mains input: Connect the amplifier to an earthed main outlet with an insulated
plug AC cable. Before you power the amp up, ensure the voltage switch value
corresponds to the available voltage.
15. Mains fuse slow blow T2A - 230/240V, T5A - 100/120V,
16. HT fuse: Protects the power supply in case of tube failure. If it blows, check for
a bad power tube. If tube failure is not the cause, the amp should be taken to a
qualified service center for repair. Replace broken fuse only with the same type –
slow blow T0.5A
17. Speaker outputs: connect a speaker/cabinet to the output that matches the
speaker/cabinet impedance. Always match the amplifier’s speaker output
impedance to the impedance of the speaker that is being used. Use only one type
impedance output at a time. Use only high quality speaker cables, never use guitar
cable as a speaker cable!

18. Foot switch input: connect the foot switch cable here to be able to turn Reverb
and Tremolo effects on and off via the foot switch. If there is nothing plugged in the
Foot switch input, both the Reverb and Tremolo effects are active (but can be
turned off by turning down the Reverb knob and Tremolo Depth knob).
19. Build in series loop for instrument level effects.
SPECIFICATIONS:
• Preamp tubes: 5 x ECC83/12AX7 • Power amp tubes 2 x EL34 or 2 x 6L6
• Output power 51 Watts
• Power consumption Max 200 VA
• Combo Speaker Jensen Stealth 12” 8 ohms or 2x12” Jensen Stealth 16 ohms (total load
8 ohms)
•Dimensions (W*D*H):
Combo ( 1 x 12 ) 61 x 26 x 50,5 cm / 24” x 10,25” x 20”
Combo ( 2 x 12 ) 71 x 26 x 50,5 cm / 24” x 10,25” x 20”
•Head 61 x 26 x 27,6 cm / 27,95” x 10,25” x 11”
• Weight:
1 x12” Combo 24,5 kg / 54 lbs
2X12” Combo 26,9 kg / 59,3 17,3lbs
Head 17,3 kg / 38,2 lbs
Specifications are subject to change without notice!
MAD PROFESSOR AMPLIFICATION LTD
Kauppakuja 2 14200 Turenki Finland
[email protected]
Tel. [phone]
www.mpamp.com
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