Ampeg CLASSIC-U
Ampeg CLASSIC-U
Ampeg CLASSIC-U
Ampeg CLASSIC-U Analog Bass PreAmp Pedal
Product images are provided for reference and may not represent the exact model, configuration, or included components.

At A Glance

Signal to Noise Ratio (50 Hz @ 300mV RMS
75 dB
Maximum Gain
+18 dB
Bass
+7/–20 dB @ 40 Hz
Mid
+5/–11 dB @ 500 Hz
Treble
+10/–10 dB @ 4 kHz
Ultra Hi
+7 dB @ 8 kHz
Ultra Lo
+2 dB @ 40 Hz / –10 dB @ 500 Hz
Impedances
Input: 1 M Ω Normal, 83 k w/–15 dB Pad, Output: 120 Ω
Power Requirements
Internal: 9V Battery / External: 9VDC, ≥20 mA, center negative
Size (H x W x D
2.2 in x 2.6 in x 4.5 in / 56 mm x 66 mm x 114 mm
Weight
0.6 lb / 0.3 kg (approximately)
Description

Ampeg produced the CLASSIC-U as a compact analog bass preamp pedal, positioning it as a pedalboard-friendly entry point into the brand's preamp character. The unit offered a portable alternative to a full amplifier preamp stage, designed to reproduce tonal qualities associated with the Ampeg amplifier line.

The CLASSIC-U's tone shaping centred on a three-band stack — Bass at 40 Hz, Mid at 500 Hz, and Treble at 4 kHz — supplemented by two switched voicing circuits: Ultra Hi, which adds 7 dB at 8 kHz, and Ultra Lo, which combines a 2 dB lift at 40 Hz with a 10 dB cut at 500 Hz for a scooped low-end character. Maximum gain is +18 dB, and the input stage presents 1 MΩ impedance in normal operation, dropping to 83 kΩ when the –15 dB pad is engaged. Output impedance is 120 Ω. The unit runs on an internal 9V battery or an external 9VDC centre-negative supply drawing at least 20 mA.

Owners requiring adjustment to internal signal routing, pad circuitry, or power supply compatibility should consult a qualified electronics technician experienced with effects pedal signal chains.

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