AmpEQ Classic Bass Preamp

Bring legendary Ampeg™ tone to your Reason rack with classic bass preamp.
The AMPEQ Classic Bass Preamp is a extennded version of the iconic Ampeg™ Classic Analog Bass Preamp pedal. A modern-day tribute to the golden age of bass amplification.

Designed to capture the unmistakable warmth, punch, and midrange authority of the Ampeg
SVT™ lineage, AMPEQ effect delivers the bold, analog character that defined decades of rock,soul, funk, and reggae.
From fat low-end drive to vintage-inspired grit, it’s equally at home on bass guitar, synth bass, drum bus, or any source that needs weight and presence.
Whether you’re laying down DI tracks, reamping virtual instruments, or sculpting mix-ready tone, this plugin offers studio-quality bass shaping in a fast, musical interface.

Experience the depth of Ampeg™ classic sound. Whether you’re a bassist, producer, or sound
designer, this preamp delivers powerful tone shaping, vintage character, and studio-grade flexibility—ideal for adding low-end authority and analog warmth to your productions.

Try it out, and hear the bottom end of your mix come to life!

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The History of Bass Preamp effect

The Ampeg™ sound is more than just bass—it’s a legacy. Inspired by the legendary SVT tube amps introduced in 1969, the Ampeg™ Classic Bass Preamp distills that unmistakable tone into a portable format. The original pedal was designed to deliver Ampeg’s flagship sound without the bulk of an 85-pound head and 8x10 cab, and this Rack Extension continues that mission
with studio precision.

Its sound is rooted in the classic Ampeg EQ architecture, with a musical 3-band tone stack and iconic Ultra Lo/Hi switches that shape the frequency response for era-accurate bass voicing—from the thump of James Jamerson and Bootsy’s bounce, to punk grind and prog rock bite.

Careful attention has been paid to impedance behavior, gain structure, and subtle EQ curves—letting you dial in tones ranging from deep, dubby lows to snappy, articulate highs. Whether clean or colored, this is true analog tone in digital form

Bass Preamp Controls

LEVEL: Master output volume of the processed signal

ULTRA LOW: Adds weight on low-end (boost +2 dB @ 40 Hz), & scoops mids (-10 dB @ 500 Hz)

ULTRA HIGH: Adds high-end air (+7 dB @ 8 kHz)

BASS: Adjust low frequency level. Boost/cut lows (-12 to +7 dB @ 40 Hz)

MID: Adjust the midrange frequnecy. Cut or enhance growl (-11 to +5 dB @ 500 Hz)

TREBLE: Tame or add bite (-10 to +10 dB @ 4 kHz).
Rotate clockwise for cuts trough, or counter-clockwise for a “contoured” sound

ANALOG VIBE: Subtle roll-off, mimicking analog coloration with additional capacitance emulation

INPUT MODE: Switch between 3 signal input modes (Bright, Default, Normal)

• BRIGHT (1MΩ) For clarity with passive pickups
• DEFAULT Neutral setting.
• NORMAL (100kΩ) Warmer feel for active instruments (active electronic, high output level pickups).

Rear panel controls:

INPUT TYPE: Switch incoming signal between two modes:
- PASSIVE BASS (0 dB)
- ACTIVE BASS (-15 dB). Reduces the input level of active electronic or high output pickups

BASS MONO: Convert stereo signal from the selcted limit of frequency to the mono signal (in range 0–1000 Hz) to tighten low-end content.

How to Use AMPEQ

1. Choose Input Mode: Use Bright for most passive basses, or Normal for active basses.
2. Set EQ: Try Bass +3 dB, Mid flat, Treble +5 dB as a starting point.
3. Engage Ultra Lo/Hi: Add boom or sparkle depending on your source.
4. Analog Vibe: Toggle to smooth out harsh highs or emulate vintage coloration.
5. Adjust Output Level: Match levels for A/B comparisons or mix integration.

Tip: Use the rear panel’s -15 dB pad with high-output pickups or synths to avoid clipping and maintain headroom.

What input mode to select?

• Passive pickups lose highs when loaded, the +3dB @ 3kHz shelf mimics the “unloaded” sound (like a 1MΩ input).
• Active basses don’t need brightness boosts (the flat EQ avoids harshness).

• Normal mode - is neutral settings by your own choice.

• Gain differences replicate the SVT’s input sensitivity.

Testing & Refinement

Passive P-Bass:
Bright mode should sound clearer, less muddy.
Normal mode should sound duller (but usable with the -15dB pad).

Active bass:
Normal mode should sound clean and balanced.
Bright mode might sound harsh (as expected—it’s for passive basses).