PreSonus Acousti-Q - Manual (Page 14)

3 CONNECTIONS
3.1 INSTRUMENT INPUT/BLENDER
The instrument input is designed to handle 1⁄4” TRS or TS plug from instruments
such as guitars and basses. The TRS style connector is used with instruments
that are equipped with both mini-condensor microphones and piezo pick-ups.
A TS style jack is used with instruments equipped with only pick-ups. This
instrument input is designed to accept either type of plug. (It should be noted
that the Blender function requires the output of an instrument that has both
a pick-up and a mini-condensor microphone.) Care should be taken not to
overdrive the input of the ACOUSTI-Q with instrument preampliers or line
level output.
3.2 VACUUM TUBES
The ACOUSTI-Q comes supplied with a 12AX7 vacuum tube that provides excel-
lent performance characteristics. We expect some owners of the ACOUSTI-Q
will try different brands of 12AX7 tubes to investigate the various performance
possibilities they might provide.
3.2.1 REPLACING THE VACUUM TUBE
1. Disconnect the ACOUSTIC-Q from it’s electrical outlet.
2. Remove the six screws that attach the top of the unit’s chassis. The vacuum
tube is mounted in a horizontal fashion in the middle of the ACOUSTI-Q’s body.
3. Carefully remove the vacuum tube from it’s receptacle. Be sure to hold the
socket in place while gently wiggling the vacuum tube out.
4. Insert the replacement vacuum tube into the receptacle. Care should be
taken to properly align the pins on the vacuum tube to the corresponding holes
in the receptacle. (Caution should be taken not to break the circuit board.)
5. Replace the top of the ACOUSTIC-Q.
6. Restore power to the unit and resume operation.
Remember, tube life and performance are affected by how often a tube is
used and by how hard the tube is driven when in use. Signs of wear may be
exhibited by poor performance or by the tube becoming microphonic. Periodic
replacement of vacuum tubes is recommended. The time interval for tube
replacement may vary greatly. If you notice deterioration in sound quality of the
ACOUSTI-Q then it’s time to change the tube.
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