EQUALIZATION
LOW EQ CONTROL (8)
The Low EQ Control is of the active”shelving type”and provides lowfreqency boost in the clockwise positions and low frequency cut in the counterclockwise positions. Flat response is obtained in the vertical 12:00 o’clock position, as indicated by the zero in the center of the rotation. The action of this control is more or less conventional and no operational problems should be encountered. You should, however, avoid excessive low end boost since this greatly affects your amps power reserve (headroom). The Low EQ Control is capable of more than 15 dB of boost or cut and you should be aware that each 3 dB of boost doubles the amount of power necessary to produce the desired amount of low end. Even the 200 watt RMS capability of the Nashville 400 may be overloaded by excessive low end boost at high volume levels.
MID EQ CONTROL (8)
This control enables a boost or cut of 15 dB in the vital mid-range frequencies. Added versatility is possible because of the ability to vary the operating center point throughout the mid-range from 150 Hz to 1500 Hz by use of the freqency shift control. The Mid EQ Control works in a similar manner to the Low and High EQ Control and should present no operational difficulties. Clockwise settings increase “fat” mid-range frequencies and counterclockwise settings will result in a “thinnersound” with less mids apparent. Noticethezero position at 12:00 o’clock will indicate no change is taking place to the mid-range frequencies. Asetting of zero will renderthe Mid Control ineffective, because the mid-range isat that point totally flat. Most steel guitar equalization settings for the mid-range control will be from minus 3 to minus 9 usually and these settings, of course, will vary from player to player because of technique and outboard equipment used. Patch cords, volume pedals, effectsdevices, guitar pickups, etc., all tend to have someeffect on overall tonality and forthat reason we are not usually able to give a “cookbook” set of equalization settings for any particular instrument. Experience has proven that mid-range cut is generally more pleasing for most instruments (especially steel guitar and fiddle).
SHIFT CONTROL (7)
The Shift Control has the ability to move the frequency where the mid-range control has its effect. The “sweep” capability of the shift can position the middle control at any point along thefrequencyspectrum between 150 Hz and 1500 Hz. This is a wider range than was included with the Shift Control in our older model Session@ 400. Please be aware that the Shift Control works in conjunction with the Mid-range Control and any conditioning that is performed by the Mid-range Control may be, once again, altered by the Shift Control. For instance, asetting on the minus (cut) position with the Mid Control will create a dip or a notch in the mid-range response and the shift can relocate this notch anywhere between 150 Hz and 1500 Hz. With this notch preselected with the Mid-range Control you will notice that counterclock- wise settings near 150 Hz with the shift will yield thinner sounding mids, while clockwise settings will yield fatter sounding mids. Note also that just the opposite effect is possible when you select a boost with the middle control and rotate the shift from 150 Hz to 1500 Hz. Most steel guitar players will adjust their Shift Control in the area between 600 Hz and 800 Hz depending on the player, once again, and the equipment used. For lead guitar, a shift setting of 300-500 will usually yield best results.
HIGH EQ CONTROL (6)
This control is of the active peak/notch type and provides true boost or cut in lower high frequency ranges (2 KHz). As with the low and the middle controls, the high EQ produces boost in the clockwise positionsand cut in thecounterclock- wise settings while flat response is obtained in the vertical (12:00 o’clock) position. The action of this control is conventional but pronounced. Care should be taken not to overboost the highs since this can contribute an unpleasantly harsh response as described above. Notice also that there will be a slight interaction between the Shift Control and the High EQ Control when the shift is operated up near 1500 Hz because this places the middle control and the high control very close to each other along the frequency spectrum.
PRESENCE CONTROL (9)
The Presence Control has been brought forth from the Session@ 400which was one of our first amplifiers to include this high frequency element. The control is a conventional rotary type device, but acts very much like a bright boost system. Once again, this control is active with 15 dB of cut or boost and takes effect at approximately 5 kHz. Extra brightness, which emphasizes “picknoise”and extreme silky highs, may be added with this Presence Control in the boost position. If your preference in tonality is without any additional “sizzle” on the top end then you may require the Presence Control to be operated on the minus or counterclockwise position. Most guitar applications require a slight amount of presence boost but it is usually in the neighborhood of only about 3 dB. Once again, these settings will vary according to equipment used and player technique. Please be aware that additional high frequency boost may be obtained with the “Pull Bright Control” (see explanation for “Pre Gain/Pull Bright”).
REVERB CONTROL (10)
The Reverb Control determines the amount of delayed (reverb) signal mixed back into the output and its operation is conventional. In addition, the reverb may be switched on and off through the use of a remote footswitch. This footswitch patches into the back panel footswitch input jack and is conventional in operation. We have included a new reverb circuit featuring a current source drive together with the new Accutronics three spring reverb unit. The action of this control is “0” to “10”and should provide more than enough reverberation for most any situation.
DDT’” COMPRESSION LED (11)
The Nashville is a compact and powerful amplifier that features a 210 watt RMS power amp (at 4 ohms) with a full compliment of equalization controls and a new type of dynamic compression. The compression effect enables us to maximize the performance of the amp/speaker combination. We have determined through much research that the compression circuitry should prevent the poweramplifier/speakercombination from running out of headroom (clipping) and should be as simple to operate as possible to avoid undue complications for the user. Our compression circuitry is very effective. Because of the dynamics and the percussive nature of plucked strings, it is quite common to activate the compression as indicated by the limit LED at reasonably low output levels. One should not be concerned that the limit LED indicates compression virtually constantly during a performance, since this is what it was designed to do. The system was designed to maximize the dynamics available from the amp within its power output capabilities. We have not included other compression controls since we have designed an exclusive distortion detection system which is patented and senses conditions that might cause overload and activates compression only when clipping is imminent. This technique effectively utilizes every precious watt available from the Nashville 400.
