User manual HUGHES & KETTNER BASSBASE400

[. . . ] DYNACLIP eliminates undesirable power amp distortion and provides 20% additional headroom in comparison with conventional power amps. , NOTCH FILTER: This adjustable, extremely narrow-band filter is not used for normal soundshaping, but to suppress specific stage and room resonances (e. g. a stage floor's sympathetic vibrations). PROTECT LED: Illuminates when one of the power amp circuit breakers has tripped. Inadequate ventilation, a short circuit in the SPEAKER OUTS or direct current in the output will trigger the circuit breaker. TEMP LED: Indicates that thermal overload (overheating) is the reason why the protective circuit has activated (e. g. [. . . ] If you cannot achieve tube saturation even with the gain wide open, deactivate the -10 dB button (not depressed). Note that the TREBLE control is situated before the tube stage in the signal chain, yielding smoother harmonic overtones. If the CLIP LED illuminates when you dial in higher TREBLE settings, simply adjust the GAIN control to a lower level. 3. 0 OPERATING THE BASSBASE 400 3. 1 THE INPUT AND BASIC EQ SECTIONS The response of the BASSBASE 400 tube preamp depends largely on the instrument you are playing, its pickups and signal level, as well as your playing style. The -10 dB and GAIN controls simplify and significantly expedite your search for the proper level. Although your ears are the ultimate authority, the PREAMP LEDs are also great visual reference tools for this task. To adjust the gain properly, turn your instrument's volume all the way up and spank the plank hard by slapping or really 7 BASSBASE 400 - MANUAL 3. 2 THE VARIMETRIC EQ The BASSBASE 400 VARIMETRIC EQ and FX LOOP can be switched via the buttons on the front panel or remotely via optional footswitches. NOTE: Please make sure you set the front panel buttons fo the OFF position (not depressed) when you want to activate these functions via footswitch. Handle the VARIMETRIC voicing sections as you would a semiparametric EQ. The difference lies in the VARIMETRIC EQ's auto-variable bandwidth and slope, which enable you to achieve substantially more musical results. The easiest way to use it (and the best way to acquaint yourself with how it works) is to do the following: - Turn the LEVEL control all the way up so you can really hear the results when you tune a frequency range in the lower midrange. - Dial in the desired low-mids center frequency via the FREQ HZ control. If you stop rotating the pot at any point you will hear that particular frequency especially pronounced. You may find that a given frequency is particularly annoying, but not to worry, help is near: simply attenuate the culprit. - You can now use the LEVEL control to amplify/attenuate selected frequencies as desired. - Use the same procedure to tune the upper-mid frequencies via the FREQ KHZ and LEVEL controls (LEVEL to maximum, tune FREQ KHZ, then adjust LEVEL to amplify/attenuate the chosen frequencies. - Hit the EQ ON button if you need to compare your EQed tone to the basic tone. Why call if "VARIMETRIC" rather than "PARAMETRIC?" Even though you handle the VARIMETRIC the same way you would a conventional semi-parametric EQ with its fixed filtering, it is a much more sophisticated sound-shaping tool. The filters, rather than the being geared to a fixed frequency range, are variable, enabling you to fine-tune your tone for a truly musical result. LOW/MID VARIMETRIC 20 dB 10 dB 0 dB -10 dB -20 dB 80 Hz 160Hz 250 Hz 400 Hz 560 Hz 800 Hz 1 kHz This frequency diagram depicts the effects of the VARIMETRIC EQ on the lower-midrange. As clearly illustrated, the boost of a complete octave range is very wellrounded and even, ideal for clearly establishing the basic sound character. Attenuation occurs at a much narrower band width allowing you to accurately target undesirable frequencies. If you amplify a given frequency range, the frequencies bordering its outer parameters are smoothed out with a touch of attenuation, and if you attenuate a given frequency range, the frequencies bordering its outer parameters are gently amplified, achieving an audio contour which intensifies the overall EQ effect. HIGH/MID VARIMETRIC 20 dB - If you leave the LEVEL control in the 12 o'clock position for a given frequency, that frequency will not be affected. With a bit of practice, you can tune an attenuated frequency range (rather than artificially overemphasizing it first like we just did), but keep in mind that for the human ear, attenuated frequencies are generally more diffult to discern. 10 dB 0 dB -10 dB -20 dB 0. 5 kHz 0, 85 kHz 2, 5 kHz 4 kHz 6, 5 kHz 10 kHz 15 kHz Higher-midrange equalization: The higher the frequency, the broader the bandwidth processed by the VARIMETRIC EQ, much in the way the human ear registers the upper end. Attenuation occurs at a much narrower band width so you can accurately target undesirable frequencies and avoid the dreaded broad-band hollow midrange effect. BASSBASE 400 - MANUAL 3. 3 THE NOTCH FILTER Undesirable frequencies such as those caused by resonant object in the room or floor boards in the stage can be suppressed via the NOTCH FILTER. [. . . ] Do not sever the ground of the connected devices under any circumstances!If this doesn't eliminate the noise, you must ensure the connection is galvanically separated by routing the signal through a DI box. E4) The 5. 0 POSSIBLE ERROR SOURCES/ TROUBLE-SHOOTING E1) The BASSBASE is not getting any power: - Check the mains cable to see if it is connected properly. If this fuse also blows, consult your Hughes & Kettner dealer. E2) The BASSBASE is connected properly, but no sound is audible. - The MUTE function is activated. Press the MUTE button! - One or several GAIN and MASTER controls are turned all the way down. [. . . ]