The legendary tone and portability of the all-tube Ampeg Portaflex amplifiers is faithfully reproduced in the PF-20T. This all-tube Portaflex head provides a harmonically rich and studio-worthy 20 watts of pure Ampeg tone to satisfy the most discerning bass player. Featuring simple user-adjustable bias adjustment for easy tube replacement and pre-amp and transformer balanced direct outs for maximum versatility. Plus, no speaker load is required for silent recording or even use as a dedicated tube DI. Pair it with the PF-112HLF for the ultimate compact all-tube bass rig.
- This control adjusts the input level of the signal reaching the preamp
- Use to adjust the low frequency level of the amplifier. The low frequency output is flat at the center position.
- Use to adjust the midrange frequency level of the amplifier. The midrange frequency output is flat at the center position. Rotate the control counter-clockwise for a “contoured” sound (more distant, less midrange output), or clockwise for a sound that really cuts through
- Use to adjust the high frequency level of the amplifier. The high frequency output is flat at the center position.
- Use to control the overall output level. It affects the Speaker Outputs and the Preamp Output.
- Pre/Post EQ
- Thesignalatthe Preamp Out can be set to either Pre-EQ or Post-EQ with this switch. With the switch in the IN position, the signal at the preamp out is Pre-EQ. This is a direct output not affected by any EQ or Boost settings. With the switch in the OUT position, the signal is Post-EQ and is controlled and modified by the tone controls.
- Ground Lift
- When this switch is engaged, it connects the ground connection to help reduce residual hum and buzz sometimes picked up in the signal cables.
- Preamp Balanced Line Out
- This signal may
be used to feed an external power amplifier, mixing console, interface, or house PA system.
- Transformer Balanced Line Out
- This signal may be used to feed an external power amplifier, mixing console, interface, or house PA system.
- Speaker output
- This mono, 1/4" TS Output jack supplies speaker-level power to the speaker cabinet. The rated power output is 20 Watts RMS into 4 or 8 Ω. Make sure the total speaker impedance load is 4 Ω or greater. For example, you could connect:
• Two 16 Ω speakers in parallel = 8 Ω
• Two 8 Ω speakers in parallel = 4 Ω
Power and Ohm
- RMS Power Output:
- 20W @ 4 or 8 Ω
- All-tube 2 x 12AX7
- Power Amp:
- All-tube 2 x 6V6
- 7.3 x 13.0 x 10.4 in / 185 x 330 x 264 mm
- 15.2 lb / 6.9 kg