Blackstar HT-20RH MK III Guitar Tube Amplifier Head

Introduction

This manual provides essential information for the safe and effective operation of your Blackstar HT-20RH MK III 20-watt guitar tube amplifier head. Please read these instructions thoroughly before use and retain them for future reference.

The Blackstar HT-20RH MK III is a versatile 20-watt tube amplifier head designed for guitarists seeking professional-grade tone. It features two footswitchable channels, power reduction capabilities, an IR-based CabRig speaker simulator, and built-in reverb, making it suitable for both stage and studio environments.

Important Safety Instructions

• Read Instructions: Carefully read and understand all safety and operating instructions before using this product.
• Retain Instructions: Keep these instructions for future reference.
• Heed Warnings: Observe all warnings on the product and in the operating instructions.
• Water and Moisture: Do not use this apparatus near water (e.g., bathtubs, sinks, wet basements, swimming pools).
• Ventilation: Ensure proper ventilation. Do not block any ventilation openings. Install in accordance with the manufacturer's instructions.
• Heat: Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
• Power Cord Protection: Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.
• Cleaning: Clean only with a dry cloth.
• Servicing: Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.
• Grounding: This apparatus must be grounded.

Setup

Follow these steps to set up your Blackstar HT-20RH MK III amplifier head.

1. Unpacking: Carefully remove the amplifier head from its packaging. Inspect for any signs of damage.
2. Speaker Connection: Connect the amplifier head to a suitable speaker cabinet using a high-quality speaker cable. Ensure the impedance of the cabinet matches the amplifier's output impedance (typically 8 or 16 ohms). Never operate the amplifier without a speaker load connected, as this can cause severe damage.
3. Power Connection: Connect the supplied power cord to the amplifier's IEC inlet and then to a grounded AC power outlet.
4. Guitar Connection: Plug your guitar into the 'INPUT' jack on the front panel using a standard instrument cable.
5. Footswitch Connection: If using the optional footswitch, connect it to the 'FOOTSWITCH' jack on the rear panel.
6. USB Connection (Optional): For direct recording or CabRig software control, connect a USB cable from the amplifier's USB port to your computer.
7. Effects Loop (Optional): External effects pedals can be connected via the 'SEND' and 'RETURN' jacks on the rear panel.

Front view of the Blackstar HT-20RH MK III amplifier head, showing controls and input jack.

Operating Instructions

Familiarize yourself with the controls and functions of your amplifier.

Powering On/Off

1. Ensure all volume controls are set to minimum before powering on.
2. Flip the 'POWER' switch to the 'ON' position. The indicator light will illuminate.
3. Allow a few moments for the tubes to warm up before playing.
4. To power off, turn all volume controls to minimum, then flip the 'POWER' switch to 'OFF'.

Front Panel Controls

• INPUT: Standard 1/4" jack for connecting your guitar.
• CLEAN Channel:
  • VOLUME: Adjusts the overall output level of the clean channel.
  • TONE: Shapes the tonal characteristics of the clean channel.
  • VOICE: Selects between two distinct clean voicings.
• OVERDRIVE Channel:
  • GAIN: Controls the amount of overdrive/distortion.
  • VOLUME: Adjusts the output level of the overdrive channel.
  • TONE: Shapes the tonal characteristics of the overdrive channel.
  • VOICE: Selects between two distinct overdrive voicings.
• OD EQUALISATION:
  • ISF (Infinite Shape Feature): Blackstar's patented control that shifts the amplifier's tone stack from a 'British' characteristic (counter-clockwise) to an 'American' characteristic (clockwise).
  • TREBLE: Adjusts the high-frequency response.
  • MIDDLE: Adjusts the mid-range frequency response.
  • BASS: Adjusts the low-frequency response.
• MASTER Section:
  • REVERB: Controls the level of the built-in reverb effect.
  • LEVEL: Adjusts the overall output volume of the amplifier.
• POWER REDUCTION (20W/2W): A switch to select between full 20-watt output or a reduced 2-watt output for lower volume playing without sacrificing tone.

Detailed view of the amplifier's front panel controls.

Rear Panel Connections

• SPEAKER OUTPUTS: Connect to your speaker cabinet. Ensure correct impedance matching.
• EFFECTS LOOP (SEND/RETURN): For connecting external effects pedals.
• USB AUDIO: Connect to a computer for direct recording or to access the CabRig software.
• CABRIG OUTPUT: Speaker emulated output for silent practice, direct recording, or connecting to a PA system.
• FOOTSWITCH: Connect the optional footswitch for channel switching.

CabRig Speaker Simulator

The HT-20RH MK III features an advanced IR-based CabRig speaker simulator. This allows you to select from various virtual speaker cabinets, microphones, and room environments. Access and customize CabRig settings via the Blackstar Architect software when connected via USB. The CabRig output can be used for silent practice with headphones, direct recording, or sending a speaker-emulated signal to a mixing console or audio interface.

Maintenance

Proper maintenance ensures the longevity and optimal performance of your amplifier.

• Cleaning: Disconnect the amplifier from power before cleaning. Use a soft, dry cloth to wipe down the exterior. Avoid abrasive cleaners or solvents.
• Tube Care: The amplifier uses vacuum tubes which have a finite lifespan. If you notice a decrease in performance, loss of volume, or unusual noise, the tubes may need replacement. This should be performed by a qualified technician.
• Ventilation: Ensure the amplifier's ventilation openings are clear of obstructions at all times to prevent overheating.
• Storage: Store the amplifier in a dry, temperature-controlled environment away from direct sunlight and extreme temperatures.

Troubleshooting

If you encounter issues, refer to the following common troubleshooting steps:

• No Sound:
  • Check all cable connections (power, speaker, guitar).
  • Ensure the amplifier is powered on and the volume controls are not at minimum.
  • Verify the speaker cabinet is properly connected and functioning.
  • Test with a different guitar cable and guitar.
• Humming or Buzzing:
  • Ensure the power cord is securely connected and grounded.
  • Try plugging the amplifier into a different power outlet.
  • Check for faulty instrument cables or pedals in the signal chain.
  • Move the amplifier away from other electronic devices that may cause interference.
• Weak or Distorted Sound:
  • Check the 'GAIN' and 'VOLUME' settings for both channels.
  • Ensure the speaker cabinet is correctly connected and not damaged.
  • Tubes may be worn out and require replacement by a qualified technician.
• Loud Pop when Switching Channels: This can sometimes occur with tube amplifiers. Ensure your guitar's volume is turned down when switching channels to minimize the audible pop. If the issue persists or is excessively loud, consult Blackstar support.

If these steps do not resolve the issue, contact Blackstar customer support or a qualified service technician.

Specifications

Warranty and Support

Blackstar products are designed and manufactured to the highest standards. For information regarding warranty coverage, terms, and conditions, please refer to the warranty card included with your product or visit the official Blackstar Amplification website. For technical support, troubleshooting assistance beyond this manual, or service inquiries, please contact Blackstar customer support directly.

Online Resources: For the latest software updates, additional resources, and frequently asked questions, visit the official Blackstar Amplification website.