©Mojotone
®
Blackface Twin Reverb
®
Style Amp Kit Manual 2012
Page 7
**WARNING**
The Voltages found inside your amp can cause serious harm or even death. Never
attempt to service your amp while a power source is connected.
Testing the Amp
•
*WARNING* Never stick your hands inside amplifi er especially while power is on!
•
Plug in speaker
•
Turn amp on without tubes installed fi rst, checking transformers and components for shorting, excessive
heat, arcing, smoking, etc.
•
Test tube socket voltage with a multimeter to ensure correct operation.
•
Turn Amp off before putting tubes in proper location, and allow tubes to heat up for approx. 30 secs. Before
playing at volume.
•
Listen. The best way to tell if there any problems with the circuit of the amp and/or tubes is just to listen....
excessive noise, popping/ crackling, hum, loud squeals, as well as ghost- echo sounds. These are all
symptoms of many common problems in tube amps.
•
If you need to service the amp after having it on, you must “discharge” the capacitors. This is done by
unplugging the amp, turning the power and standby to the on position and letting it sit for 30 mins. or so.
Always use a multimeter to check the residual voltage in the cap to make sure it is fully discharged.
Feel free to call Mojo at 1-800-927-Mojo (6656) at any time if you any questions regarding your kit.
Thanks for choosing Mojo and don’t forget to crank it up!!
**WARNING**
The Voltages found inside your amp can cause serious harm or even death. Never
attempt to service your amp while a power source is connected.
Online Resources
Grounding principles: www.aikenamps.com/StarGround.html & www.el34world.com/charts/grounds.htm
Signal Flow Diagram: www.el34world.com/charts/currentfl ow.htm
Printed Resources
“The Tube Amp Book” by Aspen Pittman
“A Desktop Reference of Hip Vintage Guitar Amps” By Gerald Weber
“All About Vacuum Tube Guitar Amplifi ers” By Gerald Weber
Photo 12 - Output Transformer Wiring
