1. Introduction
The Roland JC-40 Jazz Chorus amplifier delivers the renowned "JC clean" tone and signature stereo chorus effect in a compact 40-watt combo amp. Designed for modern guitarists, it features dual 10-inch speakers and evolved functionalities. This amplifier provides a classic stereo clean sound, ideal for use with stompbox effects, and includes a true stereo input for enhanced performance with stereo effects pedals, guitar synthesizers, amp modeling gear, and multi-effects units. The onboard effects have been updated to meet contemporary player needs.
Key features include:
- Unmistakable JC clean tone in a compact, gig-ready combo amplifier.
- Powerful stereo 40-watt output with dual 10-inch speakers for rich, full-range sound.
- True stereo input for wide sound with modelers and stereo effects pedals.
- Lush Dimensional Space Chorus for expansive stereo sound.
- Built-in vibrato, distortion, and reverb effects.
- Footswitch control for onboard effects and a stereo effects loop for external gear integration.
Figure 1: Front view of the Roland JC-40 Jazz Chorus amplifier.
2. What's in the Box
Upon unpacking your Roland JC-40 Jazz Chorus amplifier, please ensure all components are present:
- 1 x Roland JC-40 Jazz Chorus Amplifier
- 1 x Power Cord
- 1 x Owner's Manual (this document)
If any items are missing or damaged, please contact your retailer or Roland customer support.
Figure 2: Contents included with the Roland JC-40 Jazz Chorus amplifier.
3. Setup
3.1 Initial Placement
Place the amplifier on a stable, level surface. Ensure adequate ventilation around the unit to prevent overheating. Avoid placing the amplifier in direct sunlight, near heat sources, or in excessively humid or dusty environments.
3.2 Power Connection
- Ensure the amplifier's power switch is in the OFF position.
- Connect the supplied power cord to the AC IN jack on the rear panel of the amplifier.
- Plug the other end of the power cord into a suitable AC outlet.
3.3 Instrument Connection
The JC-40 features stereo input capabilities. You can connect your guitar or other instrument to either the L/MONO or R input jacks on the front panel.
- For mono instruments (e.g., standard electric guitar), connect to the L/MONO input jack.
- For stereo instruments or when using stereo effects pedals before the amp, connect to both the L/MONO and R input jacks using two standard 1/4-inch instrument cables.
Figure 3: Front panel controls and input jacks.
4. Controls and Features
4.1 Front Panel Controls
The front panel provides access to all primary sound shaping and effect controls:
- INPUT (L/MONO, R): 1/4-inch input jacks for connecting your instrument.
- BRIGHT Switch: Engages a high-frequency boost for a brighter tone.
- VOLUME: Adjusts the overall output level of the amplifier.
- TREBLE, MIDDLE, BASS: Three-band equalizer for tone shaping.
- DISTORTION: Controls the amount of built-in overdrive/distortion.
- REVERB: Adjusts the level of the onboard reverb effect.
- SPEED (CHORUS/VIBRATO): Controls the rate of the chorus or vibrato effect.
- DEPTH (CHORUS/VIBRATO): Controls the intensity of the chorus or vibrato effect.
- VIB/CHORUS Switch: Selects between Vibrato, OFF, Manual Chorus, or Fixed Chorus modes.
- POWER Switch: Turns the amplifier ON/OFF.
4.2 Rear Panel Connections
The rear panel offers various connectivity options for integration with other equipment:
- AC IN: Power cord connection.
- PHONES: Stereo headphone output for silent practice.
- LINE OUT (L/MONO, R): Stereo line outputs for connecting to a PA system, recording device, or another amplifier.
- EFFECT LOOP (SEND, RETURN L/MONO, RETURN R): Stereo effects loop for integrating external effects pedals. Includes a LEVEL switch (+4dBu/-20dBu) and a LOOP switch (SERIES/PARALLEL).
- FOOT SWITCH (CHORUS/VIBRATO, REVERB, DISTORTION): Jacks for connecting optional footswitches to control effects remotely.
Figure 4: Rear panel connections of the Roland JC-40.
5. Operating Instructions
5.1 Basic Operation
- After connecting your instrument and power, turn the POWER switch ON.
- Start with the VOLUME knob set to a low level.
- Adjust the TREBLE, MIDDLE, and BASS controls to achieve your desired clean tone.
- Gradually increase the VOLUME to a comfortable listening level.
5.2 Using Onboard Effects
- Distortion: Turn the DISTORTION knob clockwise to add overdrive to your sound.
- Reverb: Turn the REVERB knob clockwise to add spatial ambiance.
- Chorus/Vibrato: Use the VIB/CHORUS switch to select the desired modulation type. Adjust SPEED and DEPTH knobs to fine-tune the effect.
5.3 Integrating External Effects
The stereo effects loop allows for seamless integration of your external pedals:
- Connect the SEND jack to the input of your external effect unit.
- Connect the output(s) of your external effect unit to the RETURN L/MONO and/or RETURN R jacks.
- Use the LEVEL switch to match the output level of your external effect.
- The LOOP switch allows you to select between SERIES (effect processes the entire signal) or PARALLEL (effect is blended with the dry signal) operation.
6. Maintenance
6.1 Cleaning
Regularly wipe the amplifier's exterior with a soft, dry cloth. For stubborn dirt, use a slightly damp cloth and then dry thoroughly. Avoid using abrasive cleaners, solvents, or waxes, as these can damage the finish.
6.2 Storage
When not in use for extended periods, store the amplifier in a cool, dry place, away from extreme temperatures and humidity. If possible, cover the unit to protect it from dust.
6.3 Transportation
When transporting the JC-40, ensure it is powered off and disconnected from all cables. Use the integrated handle for lifting. For longer distances, consider using a protective cover or case to prevent damage.
7. Troubleshooting
If you encounter issues with your Roland JC-40, refer to the following common troubleshooting steps:
- No Sound: Check all cable connections (instrument, power, speaker). Ensure the amplifier is powered ON and the VOLUME knob is not at zero. Test with a different instrument cable or guitar.
- Humming/Buzzing Noise: Ensure all power cables are securely connected. Try plugging the amplifier into a different electrical outlet. Check for ground loops if multiple devices are connected.
- Effects Not Working: Verify that the effect knobs (DISTORTION, REVERB, SPEED, DEPTH) are turned up. If using the effect loop, ensure external pedals are powered and connected correctly, and the LOOP switch is set appropriately.
- Weak or Distorted Sound: Check the instrument's output level. Ensure the BRIGHT switch is not causing unwanted harshness. Adjust EQ settings. If using external pedals, bypass them to determine if they are the source of the issue.
If the problem persists after trying these steps, please contact Roland customer support for further assistance.
8. Specifications
| Feature | Specification |
|---|---|
| Model Number | JC-40 |
| Output Wattage | 40 Watts |
| Speakers | Dual 10-inch |
| Item Weight | 39.6 pounds (18 kg) |
| Product Dimensions (L x W x H) | 26.38 x 13.11 x 20.2 inches (670 x 333 x 513 mm) |
| Color | Black |
| Material | Stainless Steel (chassis components) |
| Compatible Devices | Guitar |
| Connector Type | 6.35mm Jack |
| Power Source | Corded Electric |
Figure 5: Roland JC-40 amplifier dimensions.
9. Warranty and Support
For warranty information, please refer to the warranty card included with your product or visit the official Roland website. Keep your proof of purchase for warranty claims.
For technical support, product registration, or service inquiries, please visit the Roland support page or contact your local Roland service center. Contact information can typically be found on the Roland website or in your product documentation.
