Peavey SESSION 500 Operating Manual

SESSION 500
Operating Guide
GENERAL DESCRIPTION
Three years ago our design group initiated the Session® 500program. Hundreds of ideas coming from professional musicians, music
dealers and field technicians as well as our own staff musicians and electronic/mechanical engineering groups were discussed,
evaluated and "distilled" into a concise set of specifications which formed the basis for the new Session®. Asthe project progressed, we
were able to draw from our experience gained in allied areas such as sound reinforcement amplification and the design of new
loudspeakers made from the "ground up" in our own speaker/transducer laboratories.
The basic amplifier/3peoker system was "road tested" for several months as a "bare bones" prototype and the input we got was that
even with the increased power and dynamic range available from the amplifier, the amp could still be overloaded, especially when heavy
"power chords" and excessive pedal action were used. During this same period of time, another R & D teem had been working on the
special problems of compression related to sound reinforcement power amps....It was natural for the two R & D teams to combine their
efforts and apply our newly developed 'Distortion Detection Technique" compression circuitry (patent pending) to even further improve
ind enhance our musical instrument amplifiers. The resulting power amp used in the Session® features DDT® compression that virtually
liminates amplifier clipping with the resulting harsh harmonics and speaker problems that are often encountered when the amplifier is
Iriven into hard clipping and square waves are delivered to the speaker system.
The new Session® tone controls retain many of the equalization characteristics of the old Session® but now include a unique "state
ariable" midrange equalizer that enables both boost and cut, as well as shifting of tho conter point of the midrange equalizer. This
:apability further enhances the tremendous tonality and dynamic range available from the Session® 500.
To further satisfy the needs of the touring professional, we have designed a variable electronic crossover into the Session's® signal
processing circuitry to allow bi-amping the system through auxiliary power ampsfepeaker systems. By including this "state variable"
/i Iter/crossover, we have enabled the Session® 500 to be the"heart" of a bi-amped system capable of performance heretofore unmatched
in musical instrument amplification.
It has been recognized for many years that the traditional steel guitar/volume pedal/amplifier arrangement commonly used is
definitely not the most ideal setup. Analysis showed that certain relatively minor circuit revisions, including some novel gain balancing
circuitry, could actually allow the volume pedal to be inserted into the amplifier itself, thus tremendously increasing the overall
performance of the system from the standpoint of dynamic range, noise, and freedom from tonal change as the volume pedal is moved
throughout its range. For the first time, the Session® 500's innovative circuitry removes the loading effects and resulting tonal changes
caused by the volume pedal's interaction with the instrument's pickup.
Musicians onstage and in the studio are constantly faced with the oroblem or -micing' tneir amplifiers, or using what is popularly
referred to as "direct boxes," to get the signals from their i nstruments into a form compatible with studio or sound reinforcement mixing
consoles. In recognition of the fact that tho consoloshould be fed a direct signal that corresponds as closely as possible to what's being
heard through the speaker system, Peavey has designed a transformer balanced line amplifier with roll-off characteristics virtually
identical to those encountered in high powered musical instrument loudspeakers. This unique circuit enables a balanced line level signal
output to be obtained from the Session® that closely matches what is being heard from the speaker to be fed to the mixing
console....without the use of auxiliary devices such as direct boxes, micing the amp with the additional problems of extraneous noises,
feedback, etc., etc.
Fu rther comments from the field indicated the desire for an advanced phasor system that would allow enhanced phasing effects with
sufficient range to create and/or simulate the many flange/phasing effects being used in contemporary music. Our circuitry utilizes the
latest in semiconductors and computer-aided design techniques and enables a tremendous range of effects from slow, almost
imporceptible effects to deep "swooshing" effects so characteristic of studio phasing/flanging units. The extreme range of the phase
oscillator yields rates from extremely slow to rapid variations characteristic of tremolo or vibrato.
Another feature often desired by professional steel men is a distortion/string effect with built-in expander and noise gate to allow
virtually infinite sustain with a very quietstandby operation. Thiscircuit can create harmonic effects similar tofidCles as well as previously
unavailable string/sustain effects. After considerable investigation into devices currently being used by studio musicians to achieve
similar effects, our R & D team devised an entirely new type of circuit that features electronic 'expansion" combined with a noise gate that
yields full and mellow string type sounds that have almost unbelievable sustain. The Session® 400 featured a unique complementary
reverb drivewhich has been retained but refined with new circuitry that allows the drive coil itself to be a part of the negative feedback Iqop
of the drive amplifier. This circuitry allows a tremendous sustain and dynamic range to be obtained from the Accutronics delay line.
Comparison with competing models will illustrate its marked superiority.
Steel players have repeatedly asked to have the capability to control the effects and reverb functions remotely. Since both handsand
feet are used when playing pedal steel, we devised a "clip on" control box which is designed to clamp on the leg of the steel. This
convenient and practical arrangement even further enhances ihe flexibility of the 500's effects features!
Overall, the Session® 500 truly represents the "stateof the art" in musical instrument amplification. Just as the Session® 400 has been
accepted by guitarists other than steel players, we feel that the new Session® 500 will be even more desirable to jazz and country players
and even rock guitarists desiring almost infinite sustain effects with tremendous tonal control, power output capability, and dynamic
range. We invite you to check and compare tho Session® 500's features with any amplifier on the market today, regardless of price, and
you will readily see that it is truly without peer.