1. Introduction
Thank you for purchasing the BOSS ST-2 Power Stack Guitar Pedal. This pedal is designed to deliver a wide range of distortion tones, from vintage crunch to ultra high-gain modern distortion, emulating the sound of tube-based stack amplifiers. Its unique SOUND knob allows for seamless blending of gain and character, providing versatile tonal options for guitarists.
Please read this manual thoroughly to ensure proper use and to maximize the performance of your ST-2 pedal.
2. Safety Information
- Power Supply: Use only the specified AC adapter (PSA series, sold separately) or a 9V battery. Using an incorrect power supply can cause malfunction or damage.
- Placement: Avoid placing the unit in direct sunlight, near heat sources, or in areas with extreme temperatures, humidity, or excessive dust.
- Handling: Do not drop or subject the unit to strong impacts. Do not attempt to modify or repair the unit yourself. Refer all servicing to qualified personnel.
- Cleaning: Use a soft, dry cloth for cleaning. Do not use abrasive cleaners or solvents.
3. Panel Layout and Controls
Familiarize yourself with the controls and connections of your ST-2 pedal.
Figure 1: Top view of the BOSS ST-2 Power Stack Guitar Pedal. This image displays the pedal's control surface, including the LEVEL, BASS, TREBLE, and SOUND knobs, as well as the CHECK indicator, INPUT, and OUTPUT jacks.
Controls:
- LEVEL Knob: Adjusts the overall output volume of the pedal. Turn clockwise to increase volume, counter-clockwise to decrease.
- BASS Knob: Controls the low-frequency response of the distortion. Adjust to add or reduce bass frequencies in your tone.
- TREBLE Knob: Controls the high-frequency response of the distortion. Adjust to add or reduce treble frequencies, affecting the brightness and presence of your tone.
- SOUND Knob: This unique knob simultaneously blends the gain amount and the character of the distortion.
- CRUNCH: (Counter-clockwise) Provides a vintage, low-gain crunch tone, reminiscent of classic rock amplifiers.
- DRIVE: (Mid-position) Offers a punchy, medium-gain overdrive suitable for rock and hard rock.
- ULTRA: (Clockwise) Delivers ultra high-gain distortion, ideal for modern metal and heavy rock sounds.
Indicators and Jacks:
- CHECK Indicator: Lights up when the effect is on. It also indicates battery status; if it dims or does not light, the battery is low and needs replacement.
- INPUT Jack: Connect your guitar or the output of another effect pedal here.
- OUTPUT Jack: Connect this to your amplifier or the input of another effect pedal.
- DC IN Jack: Connect a 9V DC AC adapter (BOSS PSA series, sold separately) here.
4. Setup
4.1 Power Supply
The ST-2 can be powered by a 9V battery or an optional AC adapter (BOSS PSA series).
Battery Installation:
- Loosen the thumbscrew at the front of the pedal and open the pedal.
- Remove the old battery (if present) and disconnect its snap connector.
- Connect a new 9V battery to the snap connector.
- Place the battery inside the battery housing and close the pedal. Secure it with the thumbscrew.
Note: The pedal includes one AAA battery, but for optimal performance and longer life, a 9V battery or AC adapter is recommended for guitar pedals.
AC Adapter Connection:
Connect the optional BOSS PSA series AC adapter to the DC IN jack. Using an AC adapter automatically bypasses the battery power.
4.2 Connecting Your Equipment
- Ensure your amplifier is turned off or its volume is set to minimum.
- Connect your guitar to the INPUT jack of the ST-2 pedal.
- Connect the OUTPUT jack of the ST-2 pedal to your amplifier's input.
- If using an AC adapter, connect it to the DC IN jack and then to a power outlet.
- Turn on your amplifier and adjust its volume to a suitable level.
Figure 2: Angled view of the BOSS ST-2 Power Stack Guitar Pedal, illustrating its compact design and connection points.
5. Operating the Pedal
5.1 Turning the Effect On/Off
Press the pedal switch to toggle the effect on or off. The CHECK indicator will light up when the effect is active.
5.2 Adjusting Your Tone
The ST-2 offers a wide range of tonal possibilities. Experiment with the knobs to find your desired sound:
- Start with the LEVEL knob at noon and adjust to match the volume of your bypassed signal.
- Begin with the BASS and TREBLE knobs at the 12 o'clock position (flat EQ).
- Turn the SOUND knob to your desired gain stage:
- For classic rock crunch, set the SOUND knob towards CRUNCH.
- For a balanced, powerful drive, set it towards DRIVE.
- For heavy, saturated distortion, set it towards ULTRA.
- Fine-tune your tone using the BASS and TREBLE knobs. Adjust them in conjunction with your amplifier's EQ settings for optimal results.
- The ST-2 is designed to be responsive to your picking dynamics and guitar volume changes, allowing for expressive playing.
6. Maintenance
6.1 Cleaning
Wipe the unit with a soft, dry cloth. Do not use liquid cleaners or solvents, as they may damage the finish or internal components.
6.2 Battery Replacement
When the CHECK indicator dims or fails to light when the effect is on, the battery is low and should be replaced. Refer to section 4.1 for battery installation instructions.
6.3 Storage
If the unit will not be used for an extended period, remove the battery to prevent leakage and potential damage. Store the pedal in a cool, dry place away from direct sunlight.
7. Troubleshooting
- No Sound:
- Check all cable connections (guitar, pedal, amplifier).
- Ensure the power supply (battery or AC adapter) is correctly connected and functioning. Replace the battery if the CHECK indicator is dim or off.
- Verify that your amplifier is on and its volume is up.
- Test with different cables or a different guitar to rule out other equipment issues.
- Weak or Distorted Sound (unintended):
- Check battery level. A low battery can cause signal degradation.
- Ensure all knobs are set appropriately. Extremely high gain settings combined with high amplifier volume can lead to unwanted noise or feedback.
- Excessive Noise/Hum:
- Ensure all cables are properly shielded and in good condition.
- Try using a different power outlet or an isolated power supply.
- Move the pedal away from other electronic devices that might cause interference.
8. Specifications
| Model Name | ST-2 Power Stack |
| Nominal Input Level | -20 dBu |
| Input Impedance | 1 M ohm |
| Nominal Output Level | -20 dBu |
| Output Impedance | 1 k ohm |
| Power Supply | 9V DC battery (6F22/9V) or AC adapter (PSA series, sold separately) |
| Current Draw | 45 mA |
| Dimensions (W x D x H) | 73 x 129 x 59 mm (2-7/8 x 5-1/8 x 2-3/8 inches) |
| Weight | 430 g (1 lb.) (including battery) |
| Accessories | Owner's Manual, 9V battery (6F22/9V) for testing purposes |
* 0 dBu = 0.775 Vrms. Specifications are subject to change without notice.
9. Warranty and Support
BOSS products are designed for reliability and performance. For information regarding warranty coverage, service, and support, please refer to the warranty card included with your product or visit the official BOSS website for your region.
For further assistance, contact BOSS customer support or your authorized BOSS dealer.
