How It Works - Sarno Music Solutions SMS Classic Owner's Manual

HOW IT WORKS

INPUT jack - This is an instrument level input with a typical 1MegΩ input impedance. It should
comfortably handle most any guitar, steel guitar, bass guitar, or acoustic instrument levels.
GAIN - This knob controls the loudness, obviously. One thing to remember is that this preamp is very
much designed as a clean machine, and it is not meant to be cranked up and overdriven like other
preamps. So keep that in mind as you put the "Classic" to use.
Bright/Dark switch - The up or "bright" position is just like what you'd find on many classic tube
amplifiers. It adds those crispy highs up above 5kHz if your tone needs it. The middle position of the
switch is off or neutral. The down or "dark" position offers pretty much the opposite of what the "bright"
position does. It gently shaves off those crispy highs for an even warmer top end. If you use this preamp in
a direct (DI) situation, it can help tame those "tweetery" highs. Thru a normal guitar type speaker, the
"dark" position is not very noticeable.
TREBLE - Yup, it controls the amount of treble.
MID - The midrange control on this preamp is a cut-only function. Cranking the "MID" knob will
approach a flat response but never boost mids. The voicing of this preamp will always tend to have some
degree of midrange dip, just like any classic guitar amp. Mid settings below 12-noon will have subtler
changes in the sound compared to settings past noon.
BASS - You guessed it. This knob controls the amount of bass frequencies in the sound.
REVERB - This knob controls the amount of reverb that gets blended in. The internal reverb is a high
quality 24bit "hall" type that has a realistic and natural sound that blends well with just about anything.
POWER - Up is on, down is off. The little blue light will tell you it's on. Remember that these are tubes,
and they typically take about 12 to 15 seconds to warm up and start working. It's recommended that you
generally leave the preamp on once it's on. Too much powering on and off can age the tubes prematurely.
Also since it's just a preamp, the unit consumes very little power and creates very little heat (unlike a tube
"power" amp), so don't be afraid to leave it on for many hours at a time if you know you'll be using it
frequently throughout the day or night. Don't leave it on 24/7, but you get the idea. If you're on set break
at a gig and want to mute your rig, just turn the gain down to zero instead of turning it off.
OUTPUT - On the back of the preamp there is an output jack. This jack is an unbalanced type output
which means you should use a simple guitar-type cord to make the connection. It's best to keep the length
of your cable run as short as possible. The output level from the preamp can be very high if you drive the
preamp hard enough, so keep that in mind when you connect the preamp to a power amplifier, a DI box,
an effects unit, a recording interface, or whatever.
OUTPUT PAD KNOB - Right next to the output jack on the rear of the preamp is the "pad" knob. By
the nature of this preamp circuit, the output level can be extremely hot. This knob helps to pad down the
output signal level to be more usable in most situations. Initially try your preamp with the front panel
"Gain" knob set around noon to 1 o'clock. Then use the rear "pad" knob to adjust the final output level to
best match your setup. You may find that the pad knob wants to be set down below noon, but feel free to
set it wherever it needs to be. This will optimize the "gain structure" as well as minimize noise.
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