Ampeg Portaflex Series User Manual

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PF-20T / PF-50T Bass Guitar Amplifier
Rear Panel Features - Continued
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20
21
20. IMPEDANCE SELECTOR: Use this
switch to match the output impedance
of the amp to the speaker(s) being used
(4 or 8 Ω).
For help in deciding the total
impedance of your system, consult the
following table.
Cabinet
Impedance
Number of
Cabinets
Total
Impedance
2 Ω 1 2 Ω
4 Ω 1 4 Ω
4 Ω 2 2 Ω
8 Ω 2 4 Ω
8 Ω 4 2 Ω
21. 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 (PF-20T)
or 50 Watts RMS (PF-50T) 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
Use (non-shielded) speaker
cables with 1/4" TS ends to
make the connections. Do not use
(shielded) instrument cables as they
may overheat.
NOTE: Unlike many tube heads, which
require a load (speaker) be attached
for operation, the PF-50T / PF-20T
may be operated with or without a
speaker load attached.
This is extremely useful for direct
recording, or for bypassing a speaker
entirely in a live setting. This is also
useful should the speaker become
disconnected during performance, as
the amplier will not be harmed.

Ampeg Portaflex Series Specifications

General

Series	Portaflex
Type	Bass Amplifier
Power Output	Varies by model (e.g., 350W, 500W, 800W)
Speaker Configuration	Varies by model (e.g., 1x15", 2x10", 4x10")
Tube Preamp	Yes (on some models)
Solid State Power Amp	Yes (on some models)
EQ	Varies by model. Typically 3-band EQ (Bass, Mid, Treble). Some models have additional EQ controls.
Inputs	1 x Instrument
Outputs	Varies by model
Impedance	Varies by model (e.g., 4 ohms, 8 ohms)
Weight	Varies by model (e.g., 35 lbs, 65 lbs)
Dimensions	Varies by model
Tone Controls	Bass, Mid, Treble