HOW TO POWER YOUR MIG-50 AMP:
1.
Flip the STANDBY switch to the ON position first.
2.
Flip the POWER switch to the ON position. The lamp should light.
3.
As soon as the tubes warm up, you are ready to ROCK & ROLL!
NOTE:
Contrary to popular wisdom, the STANDBY switch can actually do more harm
than good in some cases, such as is the case in the MIG-50. To increase the reliability
and longevity of your MIG-50, flip the STANDBY switch on FIRST.
FRONT PANEL
INPUT I Jack
– This ¼” jack is the audio input for the normal channel. The input
impedance is 1MΩ.
INPUT II Jack
– This ¼” jack is the audio input for the bright channel. The input
impedance is 1MΩ.
VOL I Knob
– Controls the overall loudness of channel I, the normal channel.
VOL II Knob
– Controls the overall loudness of channel II, the bright channel.
TONE Knobs
– TREBLE, MIDDLE, BASS and PRESENCE controls are used to alter the
amplifier’s frequency response. Adjust to taste and experiment with different settings.
Lamp
– Lights when the POWER switch is on.
Replacement part: Dial Lamp #47, T-
3-¼, 6.3V, 0.15A, bayonet base
REAR PANEL
AC INLET
– Plug the standard IEC power cable into this jack.
FUSE (MAINS)
– Within the AC inlet jack is the fuse holder. To access the fuse, use
a small flathead screwdriver to carefully slide the fuse holder out.
100VAC (Japan) ....................... 3A / 250V slow-blow 5x20mm fuse
117VAC (US/Canada) ............... 3A / 250V slow-blow 5x20mm fuse
230VAC (EU/Australia) ............. 1.6A / 250V slow-blow 5x20mm fuse
WARNING:
The AC voltage rating is marked on the amplifier’s chassis.
Failure to use the appropriate fuse could damage the amplifier.
FUSE (VALVE)
– This 1A fast-blow 5x20mm fuse’s purpose is to protect the audio
circuitry in case of overload. To access the fuse, use a small flathead screwdriver to
turn the fuse holder 180°. Hold your free hand out to catch the fuse in case it falls.
LOUDSPEAKERS –
These output jacks are for 4Ω, 8Ω, or 16Ω loudspeaker
connections only.
WARNING:
Only connect one loudspeaker output at a time. A loudspeaker must
always be connected while the amp is powered up and there is signal present at
the input. Failure to do so may damage your amp and void the warranty.
BIAS ADJUST
– This trim pot allows you to bias your power tubes without needing
to expose yourself to the dangerously high voltages contained within the amp or take
your amp to a technician just to replace some tubes. See HOW TO ADJUST POWER
TUBE BIAS section below for more instructions on using this control.
FUSE (BIAS)
– This 800mA fast-blow 5x20mm fuse should blow if a power tube
fails. To access the fuse, use a small flathead screwdriver to turn the fuse holder
180°. Hold your free hand out to catch the fuse in case it falls.
HOW TO ADJUST POWER TUBE BIAS
In order to adjust the bias of your tubes, you will first need a digital multimeter
capable of reading DC millivolts and a small flathead screwdriver. If you are
uncomfortable with using these types of tools or do not understand what power tube
bias is, please refer to a professional technician. We also encourage you to research
the subject yourself as there are plenty of resources written online and books
published by the likes of Randall Aiken, Rob Robinette, and Merlin Blencowe, to name
only a few.
WARNINGS:
1) Power tubes get very
HOT!
Allow the tubes to cool for at
least 5-10 minutes before trying to remove them. 2)
Only use 6L6/5881
style tubes.
Do not use EL34 style tubes or you will damage your tubes
and the amp and void your warranty.
After installing your new 6L6/5881 style tubes…
1.
Make sure there is nothing plugged into either input on the amp. Turn all of the
controls down to their minimum positions (zero). Turn the amp on by flipping the
POWER switch to its ON position. Wait 30 seconds and flip the STANDBY switch
to its ON position.
2.
Set your multimeter to read DC millivolts. Insert the black test probe into the
negative test point marked
(-)
. Insert the red test probe into the positive test
point marked
(+)
.
