Hartke HA4000 Mode D'emploi page 10

Guided Tour - HA4000 Rear Panel
8. Tuner Out - This standard unbalanced 1/4" jack provides an instrument-level pre-EQ,
pre-Shape and pre-Volume output signal from the HA4000 suitable for connection to any
standard bass tuner. This output is always active, regardless of the setting of the
front-panel Audio Mute switch (see #1 on page 5) or the status of the Mute Footswitch
(see #3 on page 7).
9. SBASS Out - This standard unbalanced 1/4" jack provides a line-level (+4 dBu)
pre-EQ and pre-Shape (but post-Volume control) output signal which contains
subharmonic information from the HA4000. WARNING: Because of the extremely low
frequency signal output from this jack, this should only be connected to a separate
amplifier (one with a volume control) that is driving a subwoofer. Connecting the
SBASS output to an amplifier driving a standard speaker—even one designed for
bass—may cause irreparable damage to the speaker.
10. Line Out - This standard unbalanced 1/4" jack provides a line-level (+4 dBu) post-EQ,
post-Shape and post-Volume output signal from the HA4000. You'll usually use this to
connect the HA3000 to additional slave amplifiers.
11. Direct Out - This standard balanced XLR jack provides an instrument-level output
signal which is pre-EQ, pre-Shape and pre-Volume. This is generally used to send "dry"
signal from the HA4000 to a PA system or recording mixing console.
12. Preamp Out - This standard balanced XLR jack provides a -20 dBu level post-EQ,
post-Shape and post-Volume output signal from the HA4000. This is generally used to
send the sound of the HA4000 (that is, the equalized, shaped signal) to a PA system or
recording mixing console.
13. Ground Lift switch - Used to reduce any hum or buzz that may be present in the
Direct Out and Preamp Out signals (see #11 and #12 above). When set to the right,
"Float" position, chassis ground is removed from XLR pin 1.
14. Speaker outputs - Connect any 4, 8, or 16 ohm bass cabinet(s) to these standard
unbalanced 1/4" jacks. WARNING: Because of the high power levels and low
frequency content of the signal generated by the HA4000, use only appropriately
rated speaker cabinets (at least 400 watts at 4 ohms) that are specifically designed
for bass instruments. The minimum impedance of all connected speakers must not
go below 4 ohms (i.e., don't plug in two 4-ohm cabinets!).
15. Fan - This variable speed fan provides vital cooling to your HA4000 (the hotter the
amp gets, the faster the fan blows!). Make sure that it is kept free of all obstructions and
that cool, fresh air is accessible at all times. Also, try to ensure that the HA4000 is used in
a dust-free environment.
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