Full Text Searchable PDF User Manual
George Dennis The Blue
™
Blue Beetle 15 W and Mighty Mouse 30 W Combo/Head
Reference and Owner’s Manual
Congratulations on your purchase of a George Dennis guitar amplifier “Blue Beetle”. You may have been, up to now,
aware of our company’s reputation as a maker of effect pedals. Our business has been and will always remain top
quality sound. That is why introducing a line of all tube amps is only fitting, if not at all an easy task. Our engineering
and development department has been since 1996 employing the know-how of not only the fine electronics experts
but also a number of guitarists with electronics background to develop an amplifier which will most likely satisfy even
the most discriminating and fickle demands of guitar players of all styles. To meet strict industry regulations the
design has been subjected to the most comprehensive series of safety and compliance testing. Our amplifier has
passed in all areas and fully complies with both the European and American Safety, Emission and Immunity
regulations
. Feel encouraged ? Good !
Both the “Blue Beetle” and the “Mighty Mouse” are very easy to operate. Both have 2 channels to your disposal, of
which each have independent volume controls. Tone controls are common for both the Clean and Lead channel while
the Lead channels have extra contour and gain controls.
Your new amplifier contains components of the best quality available today. These have been tested for a period of 1
year to assure durability and high temperature resistance. All amplifiers are hand crafted, hand assembled and tested
twice prior to shipment. The cabinets are built from the best quality 11-layer plywood ensuring sturdiness and
excellent tonal properties. The cabinets are finished with a tough vinyl coating, chosen to withstand rough road
conditions.
Notes regarding BIAS.
Your new George Dennis “Blue Beetle” has an Internally mounted and marked variable BIAS control. The tubes used
are the E 84 and these are configured as a DUET. Each pair of tubes selected from various manufacturers and
brands has a different BIAS requirement, therefore a minute alteration of overall sound may occur as the tubes age,
and the amplifiers bias can drift over time periods. In order to obtain the ultimate sound from your amplifier, the bias
adjustment should be checked periodically, in the same way as the idle of a car, for instance. BIAS adjustment
should be carried out by qualified personnel only. To ensure tone and safety we recommend original George Dennis
tubes, available through your local George Dennis dealer.
WARNING:
Never remove the rear cover of an amplifier while it is connected to a power socket !! The voltages inside a
valve amplifier represent a
VERY SIGNIFICANT SHOCK HAZARD.
The preamplifier tubes are three pieces of ECC 83 (12AX7 or 7025). When necessary, you can change these yourself
without worrying about BIAS.
INSTRUCTIONS FOR USE.
1. Before switching on your amplifier ENSURE you check the voltage selector on the back panel. It must be set
according to your country’s voltage standard ( USA, Canada 115 V, Europe 230 V ). The correct fuse rating for the
voltage is located on the back panel. Set the master volume knob to position 0. Plug the power cord into a suitable
power socket, than press the POWER switch on the front panel to position ON. Wait approximately 2 minutes, then
press the STANDBY switch to the ON position.
Your amplifier is now ready to use.
2. Switching channels can be done either by using the foot switch or manually by pressing marked button on the
front panel. The LED lights on both the foot switch and the front panel will illuminate to show which channel has been
selected by the foot switch. Pleas NOTE: The LED mounted on the footswitch illuminates only when engaging the
LEAD channel. When the amp is in the CLEAN mode, the LED on the food switch does not illuminate.
3 You are now ready to play. We recommend that you set all the knobs on the front panel to the position 5 and all
the left-right switches to the position left, and start to experiment with the tonal capabilities of “Blue Beetle” from
there. Do not be afraid to set the controls to their extreme positions. Let your ears be the judge.
You are in charge,
not the amplifier.
Blue Beetle and Mighty Mouse – front panel functions.
A)
HI and LO Inputs suitable for instruments with passive (HI) or active (LO) circuitry. If you plug a passive circuitry into HI
input you will obtain a darker sound.
B)
Treble tone control for Clean and Lead channels. Adjusts the amount of high frequencies.
C)
Mid tone control for Clean and Lead channels. Adjusts the amount of mid frequencies.
D)
Bass tone control for Clean and Lead channels. Adjusts the amount of low frequencies.
E)
Volume control for the Clean channel.
F)
LED’s for Clean (Blue) and Lead (Red) channels.
G)
Gain control for Lead channel. This adjust the input sensitivity of Lead channel pre – amplifier. You can increase the
amount of distortion by turning this control clockwise.
H)
Contour – frequency range control for Lead channel.
I)
Volume control for Lead channel.
J)
Reverb. This control adjusts the reverberation effect for both channels.
K)
Power switch. ( remember to check the mains voltage ).
L)
High frequency shift switch for Clean channel
M)
Mid frequency select switch for Clean channel
N)
Bright – adds treble and brightness of the Clean channel
O)
Channel select switch. Depress this to activate Clean or Lead channel.
P)
Bright – adds treble and brightness of the Lead channel.
Q)
Mid frequency select switch for Lead channel.
R)
Reverb HI/LO – When set to the LO position, the reverb sound darker and is less prominent, while in the HI position the
function is brighter.
S) Standby switch. Allow the amplifier to warm up for 2 minutes before depressing this switch.
A B C D E F G H I J
L M N O P Q R
K
S
A B C D E F G H I J S K
L M N O P Q R
Blue Beetle and Mighty Mouse rear panel functions.
A) Power voltage switch 115/230 V - before switching power On always check to make sure you have
chosen the correct voltage !!
B) Mains (power) fuse. Always use the fuse with a correct current rating. George Dennis will install
fuses with a correct rating corresponding to the voltage of the country to which a unit is being
shipped.
C) H.T. fuse. Current rating remains the same for all countries. Use only correct fuse type.
D) Reverb sensitivity for Lead channel
E) Effect loop SEND - connection to the output of the effect pedal.
F) Effect loop RETURN - connection to the Input of the effect pedal.
G) FX Loop blend.
H) Foot switch plug.
I ) Loudspeaker output jack visible on the rear panel of Mighty Mouse only. In the Blue Beetle this speaker output
Jack is hidden from view.
J ) Balanced D.I. Output.
.
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FOOT SWITCH
A) channels select switch and LED B) reverb ON/OFF switch and LED
The foot pedal is connected to the amplifier via a stereo shielded cable. The connectors are your standard 1/4” stereo
jacks.
The foot switch and the connecting cable come with the purchase of this amplifier.
A B C D E F G H J
A B C D E F G H I J
A
B
TROUBLESHOOTER´S CHECKLIST
!!! Should any sound problems occur please start troubleshooting by checking the tubes !!!
If the amp is set up but does not function, check the following items:
1. The POWER switch does not light - up after having been switched ON.
a) power cord is not plugged into an electrical outlet.
b) no power in the wall socket
c) the mains fuse is blown.
2. The POWER switch does light - up but there is no sound.
a) Make sure the STANDBY switch is ON
b) Check if the speaker is connected to the amplifier
c) turn the master volume knob past three.
d) turn the volume and gain controls of all channels past three.
e) turn all tone controls past three.
3. There is no sound, just noise.
a) check if your instrument is plugged into the amplifier.
b) disconnect all previously connected effect pedals.
c) check your guitar cord. Try another one.
If your amp is still not performing correctly, consult your authorized
George Dennis dealer.
ELECTRICAL CONNECTIONS AND SUPPLY
WARNING:
This appliance must be earthed. Please check that the supply voltage details given on the rating label (
located on the rear panel ) are in accordance with your electricity supply.
FITTED PLUG:
This appliance is supplied with a fitted plug. If the socket outlets in the home are not suitable for the
plug supplied with this appliance ( or the plug becomes damaged and requires replacement ), it should be cut off and
an appropriate three-pin plug fitted as detailed later this in section.
IMPORTANT
: A moulded plug severed from the mains lead must be destroyed immediately. Such a plug with a bared
flexible cord is hazardous if a live socket outlet.
FUSE
: If the fuse of the moulded on plug is to he replaced, remove the coloured fuse cover on the underside of the
plug, and use a suitably certified 5A fuse approved by ASTA to B51362, i.e.-, the fuse carries the ASTA mark. The
fuse cover must always be replaced. Never use the plug cover omitted. Replacement fuse covers are available from
your local authorised service agent.
FITTING A PLUG
: As the colours of the wires in the mains lead of this appliance may not correspond with the
coloured markings identifying the terminals in your plug, proceed as follows:
The wire which is coloured green and yellow must be connected to the terminal in the plug which is marked with the
letter ,E, or by the earth symbol or coloured green and yellow.
The wire which is coloured blue must be connected to the terminal in the plug which is marked with the letter ,N, or is
coloured black.
The wire which is coloured brown must be connected to the terminal in the plug which is marked with the letter ,L, or
coloured red.
Note that when fitting a plug, if the wires are tinned, the tinning must be removed and the connections made to clean
copper wire.
If a 13A (BS1363) plug is used, a 3A fuse must be fitted. If any other type of plug is used, a 3A fuse must be fitted.
WARNING:
If, after you have followed the instruction outlined above, your amplifier fails to function, please contact
your local distributor. Under no circumstances remove the rear panel of the amplifier while it is connected to the power
supply.
Electrical appliances must never be used where there is a danger of water splashing or dripping onto the unit. Your
attention is drawn to the instructions printed on the notice attached to the back of the amplifier. A exposure to
extremely high noise levels may cause a permanent hearing loss. Individuals vary considerably to noise induced
hearing loss but nearly everyone will lose some hearing if exposed to sufficiently intense noise for a sufficient time.
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS
EQUIPMENT TO RAIN OR MOISTURE.
NO USER SERVICEABLE PARTS INSIDE, REFER SERVICING TO QUALIFIED
PERSONNEL ONLY.
THE UNIT MUST BE EARTH GROUNDED !!
CE
THIS EQUIPMENT HAS BEEN TESTED AND IS CERTIFIED WITH THE
FOLLOWING:
72/23/EEC (LVD), 89/336/EEC for emissions and immunity
.
GEORGE DENNIS ® Blue Beetle / Mighty Mouse SPECIFICATIONS.
Type: Blue Beetle GD-VA15 Might Mouse GD-VA30
Power Output RMS: 15 W 30 W
Power Requirements: 115/230V AC, 50/60Hz 115/230V AC, 50/60Hz
65W 130W
Effects Send/Return Impedance: 220 ? / 220 k? 220 ? / 220 k?
D.I. OUT: Max. 1,2 V RMS, 1 kHz, 600 Ohm – for both units
Tubes: 3x ECC83, 2x EL84 3x ECC83, 4x EL84
Fuse Mains: T2A/250V for 100-120V T3,15/250V for 100-120V
Version, T1A/250V for T1,6A/250V for 230-240V
230-240V version. version.
Fuse H.T.: T 0,4 A T 0,5 A
Speaker: 1x10” Celestion 30W 1x12” Celestion 50W
Foot switch: 2 Button switch Controls, 2 Channel Select and Reverb ON/OFF
Dimensions: Height: 43,5 cm 48,5 cm
Width: 15/18 cm (Top/Button) 18/21 cm (Top/Button)
Depth: 38 cm 44 cm
Weight including foot pedal:
ATTENTION CLEANLINESS – MINDED CUSTOMERS !!
When cleaning the front and back panels NEVER use alcohol based cleaning products. Please use
water – based mild detergents ONLY.