Snake Charmer

Cooltron Tube Compressor

Analogue, warm tube compression from gently gripping to completely crazy.
Check out why there is no digital or solid state alternative to this tube compressor.

Features:
Controls of the Snake Charmer: Volume, Reduction LED, Emphasis, Compression,
High/Low Ratio Switch, Release, Attack, true bypass circuit
Tube: 12AU7
Power supply: 4x AA batteries (lifetime: 18 hours)
Dimensions: 16.84cm (W) x 15.55cm (H) x 6.4cm (D)
Weight (without batteries): 1.01 kg
Special accessories: 9V AC power supply

The “Compression” control influences two aspects of the compressor at the same time: “Ratio” and “Threshold”. “Threshold” represents the level threshold above which the guitar signal is compressed. As long as the guitar signal is below this level, it will be output unchanged. However, levels above this value are reduced. The treated signal then has fewer (noticeable) level peaks.

As a rule, you can also set how much “excess” level values ​​should be attenuated. This is done with a parameter called “ratio” (ie the factor by which peak level values ​​are reduced).

In addition to the level threshold and the compression factor, you can use this pedal to adjust the level compensation. After all, reducing the level of the compressor means that the volume decreases, and you have to add it back. Since everything is combined in one control, you can set the desired “punch” sound in no time. However, there is also a downside: if the level is increased significantly, hiss and other background noises also become louder, which is not always desirable.

LEVEL REDUCTION INDICATOR: This diode lights when the level of the input signal is attenuated. This is useful because you then know exactly when the compressor is affecting the sound.
HIGH/LOW switch: With the “HIGH/LOW” switch you can choose the general compression behavior. “LOW” represents the behavior of a guitar compressor pedal. “HIGH”, on the other hand, creates a more noticeable effect with a “popping” note onset at higher ATTACK values ​​or immediate weakening when the minimum ATTACK value is selected.

ATTACK: “ATTACK” determines how quickly the compressor starts working when the signal level rises above the threshold. Higher values ​​produce clearly marked (percussive) note onsets because even high signal levels remain unprocessed for a short time, but are still boosted by the level compensation. These short “transients” are limited by the Cool Tube when the tube has to penetrate into the non-linear range. Short ATTACK times reduce level peaks earlier. Turn the dial all the way to the left if you don't need popping bets. Turn it further to the right if the stop etc. cannot be compressed.

RELEASE: With “RELEASE” you determine how long the level attenuation of the compressor should be effective. Let's first look at the situation of an extremely short RELEASE duration. Then the level attenuation only works until the signal level drops below the threshold value again. This means that only peaks of the program signal (i.e. the guitar) are “treated”. Increasing the RELEASE duration extends the determined level attenuation (even if this is no longer necessary). Conversely, the level can still be attenuated more if the incoming signal requires it. The further you turn the RELEASE control to the right, the longer the level attenuation remains constant after the signal level drops below the threshold value. How do you determine the optimal RELEASE setting? By playing a short loud note and paying attention to when the compressor diode goes out again.

HIGH-END EMPHASIS: This control allows you to adjust how the high frequencies of the guitar signal should be compressed. This is accomplished with a filter that either boosts or cuts the high frequencies of the “side chain” signal (which controls the “opto” compression circuit). When the control is in the middle, the filter does not affect the signal. Turn the control to the left to reduce the highs (which will then be compressed less). As a result, the treble is now louder than the rest of the frequency range, resulting in a brighter sound. Turning the knob to the right increases the treble of the control signal, resulting in more compression. Then the general dynamic decreases while the effect of the compressor comes to the fore.

VOLUME: This control determines the output level of the pedal.