14
0
15
185
20
0
21
206
A1
90
A2
0
A4
0
A5
0
A6
90
A7
0
A9
0
B1
90
B2
170
B3
100
B4
90
B5
170
B6
100
B7
0
B8
0
Don’t worry if your voltages are not exactly these figures. Line voltage variations and tube
tolerance variations can change them by up to 10-15%. If everything checks out go on to the
next step.
If you do have a voltage problem and can’t sort it out or you run into any other hitches, try asking
for help on the Bottlehead Forum. It’s a wonderful tech support resource—
http://www.bottlehead.com/smf/index.php/
Final check—important!
Power the amp down and wait for 5 minutes. With the red probe now touching either the
Tip or Ring terminal on the headphone TRS jack, switch the amplifier on and monitor the
voltage of the tip or ring for about 30 seconds. It should not climb higher than about 9
volts and should then drop to zero. If it climbs much higher and/or does not reduce to
zero do not plug in headphones until you have worked out the issue and the voltage stays
below 9V.
OK, if everything checks out, shut it down and disconnect the meter.
( ) Connect a source to the inputs.
( ) Plug in your headphones.
So what are you waiting for? Throw on some music! But do make sure the volume is turned
down first so you don’t inadvertently damage your headphones.
39