The Siam Howler is a vintage-inspired low-to-mid gain fuzz that works very well either alone or being boosted. This instruction manual will walk you through how your signal flows through the pedal and how to tune it for your setup. You will need to be plugged into a quality 9v dc power supply to achieve the best performance and safety of the sensitive germanium transistors in the effect.

Effect Signal Flow

Your signal starts at the input, IN, and then goes to the Attack control. Attack acts as a signal cut to the rest of the effect. It will not completely mute your signal but it can come very close. In most cases, Attack should be set fully clockwise or backed off from fully clockwise about 10%.

From here, it will enter the Sziklai Fuzz circuit which is an interesting two-transistor setup that amplifies the gain of the transistors and seen in many vintage fuzzes (think Spirit in the Sky sounding). Additionally, the germanium transistors provide a more vintage character than is normally seen in this style of fuzz. The Hunger knob controls the voltage being fed to the circuit, the more you raise Hunger, the more gated and sputtery it will become. In general, it is best to set this to fully counter clockwise. Slight application of Hunger can create a mild octave up effect without engaging the Shriek footswitch.

If the Shriek footswitch is engaged (LED above the footswitch will be lit), the signal will be routed to a fully analog octave up circuit that will add volume to the signal. This is another vintage-inspired circuit with the ability to tune the octave to your signal by using Growl. Growl will allow you to either add harshness or mellow the octave. It is typically the most pleasant sounding around noon. Growl is interactive with both Attack and Hunger. After leaving the octave up circuitry (or bypassing it completely), we come to a hard clipping stage.

Fangs is a 4 position rotary selector. That allows you to add odd order harmonics to the signal. It also can introduce a volume drop depending on the selection. In order of loudest output to softest:

• None - bypass clipping completely
• LED - slight signal clipping with symmetrical LEDs
• Si - stronger signal clipping using symmetrical silicon diodes
• Ge - strongest signal clippling with Russian D9K diodes (roughly equivalent to 1N34A)

Next, the signal will enter the tone control, Snarl. Snarl is a low pass filter that can allow the fully unhinged signal to mellowing it completely by taming the high end treble. Finally, the signal will enter Howl, the volume control.

Depending on where The Siam Howler is located on your signal chain and how you've set the other controls, Howl should generally be fully clockwise. From here, the signal leaves the effect via the OUT jack.

Internal Trimmers

Removing the back cover of the pedal will reveal two to four trimmers (depending on the Siam Howler edition you have). Common to both are octave and mp38a bias and on newer versions, LED brightness trimmers. The LED brightness trimmers are self-explanatory. You shouldn't need to adjust either of these trimmers, but, you can adjust them to your taste.

The mp38a bias trimmer adjusts the midpoint of the signal entering the fuzz stage and can introduce more gating into the fuzz. You can't remove it completely as the nature of the fuzz is compressed and gated.

The octave bias trimmer allows you to balance the octave up that is heard when Shriek is engaged. This should be set by ear and with the Growl control set at noon.

Starting Point Configuration

Now that you have an explanation of the controls both external and internal, let's discuss the best starting point to begin to play with the Siam Howler.

• Howl - fully clockwise
• Hunger - fully counter clockwise
• Attack - fully clockwise
• Snarl - noon
• Fangs - Si
• Growl - noon

From these settings you should have a good place to tune to your liking. Depending on the pickups you are using, placing another pedal in front of this one is advisable. A tube screamer, klone, or muff-style fuzz are all great choices to stack with this pedal.