PREAMP VOLUME CONTROL – This control sets the volume of the preamp after the INPUT and FET channel gain stages and before the EQ controls. Use this control in conjunction with the GAIN control and the MASTER VOLUME control for your overall output level.
TUBE CHANNEL—
GAIN SWITCH (LOW/HIGH) – This switch sets the GAIN sensitivity for the TUBE channel. It works both like an Ac- tive/Passive switch and like a GAIN boost switch. The amber LED indicates that the HIGH setting is selected. The difference between the LOW and HIGH gain positions is approx. 10dB. Since there is a GAIN switch provided for each channel this allows the player to set different gain structures for the FET or TUBE channels.
If warm, clean tube tone is desired, we recommend that the LOW setting be used for basses with hotter output or active pickups (those with an output sensitivity over 1 Volt, generally most basses using one or two 9 volt batteries to power their on board preamp) and the HIGH gain setting be used for basses with lower output or passive pickups.
If tube compression, growl, or
PREAMP GAIN CONTROL – This control sets the input sensitivity gain of the 12AX7 TUBE preamp after the GAIN switch. The design of the TUBE GAIN structure allows you to set your tone from rich, clean tube tone to mild tube compression, to warm tube growl, to
“O/L” LED – In the TUBE channel, this LED senses the condition of the input signal after the GAIN control and also senses and warns of possible clipping in the EQ network. The “O/L” circuit does not sense distortion or overdrive in the tube. Your ears are the best judge of that for your desired tone.
The “O/L” sensing circuit is very dependent upon the output of the bass instrument pickups, the GAIN and VOLUME settings of the FET channel and the amount of EQ used i.e. the more radical the EQ boost and volume level of the PREAMP VOLUME control, the more possibility of an overload condition.
If overloading of the TUBE channel is occurring, adjusting the PREAMP VOLUME and/or PREAMP GAIN controls down will reduce or eliminate the
Note: It is OK for this LED to flash occasionally with your hardest notes played and it may flash even if the FET channel has been selected for use. This is normal and is due to the Mixing topology for the 2 channels.
PREAMP VOLUME CONTROL – This control sets the volume of the preamp after the INPUT and TUBE gain stages and before the EQ controls. Use this control in conjunction with the PREAMP GAIN control and the MASTER VOL- UME control for your overall output level.
ACTIVE EQUALIZATION (both channels) – The SHUTTLE MAX 6.0 contains two active 4 band equalizers (one for the FET and one for the TUBE channel) each with 2 sweepable parametric midrange frequency networks
Parametric filters are typically (but not always) used to reduce or remove offending frequencies in the instrument’s pickup response, or boosting response to achieve a particular voicing. Spend some time experimenting so that the process becomes creative as well as corrective.
LOW FREQUENCY CONTROL – The LOW FREQUENCY EQ section is an 80 Hz shelving curve with 15dB of cut or boost.
HIGH FREQUENCY
NOTE: These equalizer networks are similar to those found on professional sound consoles and are very useful tools. These active equalizers are very wide response type filters and a little “tweaking” goes a long way.