Bogner ATMA - User Manual

BOGNER AMPLIFICATION 1
ATMA USER MANUAL
Please read safety instructions before you use this amplifier!!!
Features:
•
2x EL84 18W Class A cathode biased power amp
•
EZ81 tube rectifier
•
2x JJ ECC83s preamp
•
JJ 5751 phase inverter
• Ch1: clean with volume and tone control, 3 position bright switch
• Ch2: crunch with gain preset (back panel) and volume control
• Ch3: solo with volume control
• Ch2+3 share gain, bass, middle and treble control, 3 position voicing switch
• Series effects loop
• Single instrument input
• Power attenuator switch for 1 and 5 watt operation
• 16, 8 and 4 ohm speaker outputs
• Functions on footswitch: Crunch (solo) and Overdrive (clean)
• Head only, complementary aluminum speaker cabinet
• All aluminum chassis with unique aesthetics
DIMENSIONS and WEIGHTS: Are subject to change anytime, Please measure your amp carefully if a
Custom Case is being made. Add ¾ inch for each, handle and rubber feet.
The head has two screws on each side to secure the aluminum top shell, please note theyneed
clearance on each side!
Head: 6.25” H 12.62” W 6.50” D 14 pounds
1x12 Cabinet: 17” H 17” W 10.50” D 31 pounds
Please read this owner manual completely before use to fully understand your Atma’s functions.
input
The Atma has a single high impedance input located on the front panel.
cl/cr/so toggle switch
This switch lets you select one of the three channels if no foot controller is connected. The front panel
display lets you know which controls are active. Whatever control is illuminated at a certain channel
setting can be used to alter the sound.

Summary

Control Functions

60;70;80 Toggle Switch

Gain Control

Explains how the gain control sets the amount of gain for crunch and solo channels, including the preset 'cr gain'.

Rear Panel Connections and Functions

Power Cable Socket

Instructions for connecting the power cable and locating the fuse holder.

Power Attenuator Switch

Foot Controller Input

Crunch Gain Control

Details the rear panel control for pre-setting crunch channel gain relative to the solo channel.

System Connections and Troubleshooting

Speaker Outputs

Guidance on matching speaker cabinet impedance and connecting multiple cabinets.

Troubleshooting

Advice on diagnosing and resolving common amplifier issues, including tube problems.

Fuses

Information on checking and replacing fuses, including the type and location of main fuses.

Bogner ATMA Specifications

General

Power Attenuation	Yes
Type	Tube
Preamp Tubes	3 x 12AX7
Power Tubes	2 x EL84
EQ	3-band EQ
Effects Loop	Yes
Inputs	1 x 1/4"
Reverb	No
Power	18W
Controls	Volume, Treble, Middle, Bass
Outputs	1 x 1/4"