Demonfx SIM-AMP Simplifier Bass Station

1. Introduction

The Demonfx SIM-AMP Simplifier Bass Station is a comprehensive bass platform designed for direct-to-FOH (Front of House) or studio recording applications. It integrates a bass preamp, power amp simulation, stereo cabinet simulation, and DI output, providing a versatile solution for electric bass players.

2. Setup

2.1 Powering Up

Before connecting or powering up the unit, ensure that the volume of any receiving device (PA system, audio interface, headphones, etc.) is turned down to avoid sudden 'pops' or damage.

• Use a 9V REGULATED DC adapter.
• Ensure the power supply provides a clean voltage source.
• Avoid daisy-chaining the power supply with high-current digital units to prevent noise.
• Minimum current rating: 80 mA (higher current ratings are acceptable).
• Polarity: Center negative.
• Warning: Do NOT use center positive supplies. This may damage the unit and void the warranty. Always verify polarity before connecting.

2.2 Connections

• Input Jack: Connect your bass instrument here.
• Parallel FX Send: This output carries the signal directly from the input, bypassing the preamp. Use this for effects you want to apply to the 'clean' signal chain.
• Parallel FX Return: Return point for effects connected to the Parallel FX Send.
• Preamp FX Send: This output carries the signal after the preamp stage. Use this for effects intended for the preamp's signal chain.
• Preamp FX Return: Return point for effects connected to the Preamp FX Send.
• TRS Out: Carries the main output (blend of preamp and parallel signals) or the input signal (bypass), depending on selection.
• DI OUT (XLR): Provides a balanced output of the main signal (preamp + parallel blend) for connecting to a mixer or audio interface.
• DI PARALLEL (XLR): Provides a balanced output of only the parallel signal chain (including its FX loop and LPF).
• Aux In: Connect an external audio device (e.g., MP3 player, phone) here for monitoring through headphones. This signal is not routed to the main outputs.
• Headphone Out: Connect your headphones for monitoring.

3. Operating Controls

3.1 Preamp Section

The preamp stage is based on the Ampeg SVT® design, offering a versatile and articulate tone with flexible EQ.

• GAIN: Adjusts the preamp's input gain. Settings above 70% can produce a desirable SVT-like overdrive.
• VOLUME: Controls the master output level of the preamp.
• MID FREQ (Switch): Selects the center frequency for the MID control: 400Hz, 900Hz, or 1500Hz.
• HIGH: Controls the high-frequency band, offering +/- 15dB at 3.5kHz (shelving).
• MID: Controls the mid-frequency band, offering +/- 15dB (bandpass), with the frequency determined by the MID FREQ switch.
• BASS: Controls the low-frequency band, offering +/- 15dB at 80Hz (shelving).

3.2 Blend Section

This section allows blending the preamp signal with the parallel signal and integrating the cabinet simulation.

• PREAMP BLEND: Blends the preamp signal and the parallel signal into the main output. Start with this control at 100% (preamp only) and gradually introduce the parallel signal to achieve the desired mix.
• CABSIM BLEND: Blends the cabinet simulation in or out of the main signal, allowing for different textures and low-end responses.
• PARALLEL LPF (Switch): A 3-way toggle switch that applies a 2-pole Low Pass Filter to the parallel signal.
• 100Hz: Preserves deep low end while filtering out harmonic content.
• OFF: Disables the Low Pass Filter.
• 500Hz: Preserves deep low end and low-mids in the parallel signal chain.

3.3 Cabinet Simulation

The analog cabinet simulation is based on the Omnicabsim® by DSM Noisemaker, designed to provide distinctive cabinet tones.

• MIC POSITION: Simulates a CENTER/OFF AXIS microphone position, adjusting the amount of high-end roll-off. For distorted tones, placing the 'mic' off-center works best, while clean tones often benefit from a more central position.
• CAB SIZE (Switch): Selects between different cabinet types:
• 4x10 Vented: Modern standard with extended flat low-end response and bright drivers.
• 8x10 Sealed: Huge-sounding resonant low-end cabinet with modern speakers.
• 1x15 Vented: Warm and well-rounded tone with extended low end, and creamier, smoother highs.
• SPEAKER COLOR (Switch): Simulates different speaker materials and geometries, affecting dynamics and midrange response.
• BRIGHT: Simulates aluminum cone speakers with a particular mid-high bite.
• MODERN: Provides a flatter response with enhanced highs and lows.
• WARM: Simulates vintage speakers with clearer mid response and smoother highs.

3.4 Other Switches and Controls

• PARALLEL PHASE (NORMAL/INV Switch): Adjusts the phase of the parallel signal. If other pedals invert the signal phase, this can cause frequency cancellation or total cancellation when blending signals. Adjust as necessary to correct phase issues.
• GND LIFT (Switch): Disconnects the ground connection from the XLR outputs. Use this switch if you experience hum problems when connecting to external devices.
• PHONES LEVEL: Controls the volume of the headphone output.
• PASSIVE/ACTIVE (Switch): Adjusts the input gain. Use 'Active' to lower gain for hot bass signals, or 'Passive' for a slight 6dB boost to compensate for low-level bass signals.

4. Maintenance

The Demonfx SIM-AMP Simplifier Bass Station is designed for durability. To ensure its longevity and optimal performance:

• Keep the unit clean and free from dust. Use a soft, dry cloth for cleaning.
• Avoid exposing the unit to extreme temperatures, humidity, or direct sunlight.
• Do not use abrasive cleaners or solvents.
• Protect the unit from impacts and drops.

5. Troubleshooting

• No Power: Ensure you are using a 9V-12V DC, center-negative, regulated power supply with at least 80mA current. Check all power connections.
• Humming Noise: If experiencing hum, try engaging the GND LIFT switch on the rear panel, especially when connecting to external devices via XLR.
• Thin or Weak Sound: Check the PARALLEL PHASE switch. Incorrect phase alignment between the preamp and parallel signals can lead to frequency cancellation. Adjust as needed.
• Distorted or Unclear Sound: Verify the PASSIVE/ACTIVE switch setting matches your bass's output level. An active bass into a 'Passive' setting might cause clipping, while a passive bass into an 'Active' setting might be too quiet.
• No Sound from Headphones: Ensure headphones are properly connected and the PHONES LEVEL knob is turned up. Remember that the Aux In signal only routes to headphones.

6. Specifications

7. User Tips

• Designed for Bass: This unit is specifically designed for electric bass, ensuring optimal tone and performance for bassists.
• Explore Gain Settings: Experiment with the GAIN knob to achieve a wide range of tonal characteristics, from tight and clear clean sounds to overdriven Ampeg SVT-like growl.
• Leverage Parallel Blend: Utilize the PREAMP BLEND control to mix the clean parallel signal with the overdriven preamp tone. This allows you to achieve rich, saturated sounds without sacrificing low-end clarity and natural dynamics.
• Cabsim Versatility: Don't hesitate to experiment with the CAB SIZE, SPEAKER COLOR, and MIC POSITION controls within the cabinet simulation section. These settings offer significant flexibility in shaping your final tone, from modern punch to vintage warmth.

8. Warranty and Support

For any warranty claims, technical support, or service inquiries, please contact the seller or manufacturer directly. Keep your proof of purchase for any warranty-related issues.