Fender PR 448, Instruction Manual

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FIG. A
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MODEL / TYPE Concert Reverb-Amp / PR 450 Pro Reverb-Amp / PR 448
PART NUMBER 021-5900-000 (120V, 60Hz) USA, 021-5500-000 (120V, 60Hz) USA
021-5960-000 (230V, 50Hz) Europe 021-5560-000 (230V, 50Hz) Europe
021-5940-000 (230V, 50Hz) UK 021-5540-000 (230V, 50Hz) UK
021-5930-000 (240V, 50Hz) Aust 021-5530-000 (240V, 50Hz) Aust
021-5970-000 (100V, 50/60Hz) Japan 021-5570-000 (100V, 50/60Hz) Japan
POWER REQUIREMENTS 325W 325W
POWER OUTPUT 50W RMS (Full Output) 50W RMS (Full Output)
12.5W RMS (1/4 Output) 12.5W RMS (1/4 Output)
1kHz sine into 8 ohms @ <5% THD, 1kHz sine into 8 ohms @ <5% THD
(Presence @ “1”) (Presence @ “1”)
INPUT IMPEDANCE 1M ohm 1M ohm
TUBES Two 6L6GC (P/N 053980) Two 6L6GC (P/N 053980)
Two 12AX7A (P/N 023572) Two 12AX7A (P/N 023572)
Five 12AX7WA (P/N 013341) Five 12AX7WA (P/N 013341)
One 12AT7 (P/N 023531) One 12AT7 (P/N 023531)
FUSES F200: F3A 250V (110V, 120V units) F3A 250V (110V, 120V units)
T2A 250V (230V, 240V units) T2A 250V (230V, 240V units)
( I n t e rnal Filament Fuse) F201: T5A 250V (230V, 240V units) T5A 250V (230V, 240V units)
F1 & F2: T100mA (all units) T100mA (all units)
S P E A K E R S Four Fender 10 in., 8 ohm, (P/N 048832) One Jensen 12 in., 8 ohm, (P/N 057065)
FOOTSWITCH Four–Button: Channel, Loop, Four–Button: Channel, Loop,
Reverb, Tremolo (P/N 057025) Reverb, Tremolo (P/N 057025)
DIMENSIONS Height: 25
3/4
in. (65.7 cm) 17
3/8
in. (44.3 cm)
Width: 25
3/8
in. (64.7 cm) 25
3/8
in. (64.7 cm)
Depth: 12
27/32
in. (32.8 cm) 12
27/32
in. (32.8 cm)
WEIGHT 85 lbs. (38.6 kg) 75 lbs. (34 kg)
Product specifications are subject to change without notice.
Tube life span depends upon things such as amplifier load and
playing style. Power amplifier output tubes have a shorter life
span than pre-amplifier tubes and usually need attention first.
A simple way to check if your tubes are noticeably worn, is to
replace them with a spare new set and listen for any
improvement in tone quality:
A LWAYS unplug the amplifier when replacing tubes.
Replace tubes ONLY with the proper type (see
“Specifications” below).
CAUTION: let tubes cool before handling, they get HOT...
1. Replace the OUTPUT tubes (V9, V11 in FIG. A) with a new
set. Set BIAS and BALANCE . Listen for any improvement.
2. Keep the new OUTPUT tubes in place. Replace the PRE-
AMPLIFIER tubes (V1, V2, V3, V4, V5, V6, V7, V8 in FIG. A)
with a new set. Listen for improvement.
3. Keep the new PRE-AMPLIFIER tubes in place. Put the
original OUTPUT tubes back in the amplifier. Set BIAS and
BALANCE . Listen for any improvement.
If there is a noticeable improvement in sound quality after any
of the 3 steps above, keep the tube arrangement that sounds
the best. Obtain new spare tubes for future testing and tube
replacement.