Specifications; Theory Of Operation - Fender ULTIMATE CHORUS Service Manual

Product Release No.:
Input Impedance:
Nominal Level:
Power output:
Rated Load Impedance:
Mono Effects Loop:
Stereo Effects Loop:
Dimensions:
Weight:
NORMAL CHANNEL
The first stage (U1A) sets up the initial response of the amplifier. It provides a second order high-pass filter
with a 3dB down point of 60 Hz, and a gain of about 4. The output of U1A splits to feed the NORMAL and
DRIVE channels. For the NORMAL channel, the signal feeds through the NORMAL VOLUME control
(R11) to U1B. The output of U1B drives through the tone controls and feeds summing amplifier U4A.
DRIVE CHANNEL
The signal from U1A feeds a special tone-shaping circuit which optimizes the frequency response for the
distortion circuit that follows. U2A provides the variable gain adjustment that drives the distrotion circuit. It
also acts as a bandpass filter with 3db down points at 90Hz and 4kHz. JFET Q2 mutes the input to the
distortion circuit when in the NORMAL channel mode. Diodes CR4 and CR5 are used as a voltage clamp
to prevent excessive voltage from damaging the JFET. U2b is the distortion circuit. The signal couples to
ULTIMATE CHORUS

SPECIFICATIONS

PR 204 (This is not a model number)
Greater than 1M Ohm
100mV
65 Watts RMS @ 5% T.H.D. per channel =
130 Watts RMS
8 ohms per channel
Output impedance:
Input impedance:
Nominal level:
Nominal Level:
Output Impedance:
Input Impedance:
Specifications for each channel –
Left on Tip, Right on Ring
Height: 18 1/2"
Width: 26 1/8"
Depth: 10 1/4"
47 lbs.
Product specifications are subject to change without notice

THEORY OF OPERATION

1kΩ
25kΩ
-10dBV
-10dBV
1k Ohms
94k Ohms
(47.0 cm)
(66.0 cm)
(26.0 cm)
(21.3 kg)