8
Extra Operating and Care Notes
Ground Lift Switches
Under normal circumstances these switches must always be on i.e facing downwards. If they are
accidentally turned off a loud hum will be heard. If the ground lift switches are tried turn the volume or input
level of the mixing desk as low as possible because this hum could damage what the unit is driving. (Tape
has been put on them to keep them down.)
Reverb Springs
Both of the reverb tanks house an input impedance of 8 ohms. Therefore make sure that the input
impedance selector switch is always set onto 8 ohms. This is why there is tape on the back to keep them up.
The jack to phono lead that drives the input of each spring has to be treated more like a speaker lead i.e a
high level signal lead (ordinary good quality jack to phono lead and make sure they are in good working
order). You must also always make sure that it is properly connected. The link between the send out of the
unit and input of the spring is a very important one. This is because valve amplifiers with output transformers
such as the one’s inside this unit must never be left with their outputs open circuited. If this happens
components in the unit could be damaged. Makesure before turning on the unit that the send/out is
connected to the tank input.
The second jack to phono lead which makes a link between tank output and tank return of the unit is an
ordinary screen jack to phono lead.
This unit can drive the springs really hard and as a result you can obtain this very characteristic, unique type
of reverb distortion. This can be achieved by turning up the master drive and using the reverb to control the
level of reverberated distorted signal.
Very occasionally however, springs might fail because the coils of the spring are very tiny and get warm. To
make sure this doesn’t happen check the output of the reverb by turning the reverb fully clockwise and
setting the master drive to a very low level and then hear the reverberated signal. i.e never go onto full
master drive immediately.
Beware if you turn the impedance selector switches to 600 or 1000 ohms and you do not connect them to
the tank input, we should always do. If a signal is running through the unit, one might get a small electrical
shock if you touch the tips of the phono side of the lead.
Accutronics reverb tanks can be obtained from the Tube Amp Doctor. (http://www.tubeampdoctor.com/)
When testing the unit the treble and bass cut switches must always be off. They only apply to the
reverberated signal. You can cut the base or the treble at your choice.
When downwards, the gain switch gives approximately an extra 18db’s of gain. It’s a good idea when
starting to operate the unit, that the gain switch is in the up position. (With less gain you can have finer
control of the master drive). Once you get used to it you can go for the extra gain, depending on the input
source i.e if it’s a microphone you’ll need extra db’s.
