Carver C 4000 Owners Manual

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CARVER

MODEL C4000

I:

High Fidelity Control Console

I Wide-range Full-function Preamplifier

I Sonic Hologram Generator

I Autocarrelator Noise Reduction System

I Peak Unlimiter Dynamic Range Expander
I Time Delay

CARVER CORPORATION

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CIARVERMODEL C4000

Table of Contents

i. Introduction ............................ .1
ii. Notice to Purchaser .............. . . . . . . . . .1
iii. Unpacking . . . . ...................... 1
iv. Caution Notice .......................... .1
1.0 Installation ............................ 2

2.0 Using Your C4000:
A Quick Overview .............. , , . , , 2

3.0 System Wiring

Rear Panel Connections . . . ................ 5

3.1 Phono 1 and Phone 2 in

Selecting lnpu L Capacitance .............. 5
3.2 Ground... .................... 6
3.3 Tuner In .............................. 6
3.4. Auxland Aux21n .................... 6
3.5 Tape 1 and Tape 2 In .. ............. 6
3.6 External Processor ln ................... 6
8.7 External Processor Out. ............ 7
3.3 Tape 1 and Tape 2 Out .................. 7
3.9 Main Out .. .. ................... 7
3.10Fuse., ......... .. ...8
3.11 AC Sockets .......................... 8
3.12 AC Line Cord . ................. . . . .8

4.0 The Front Panel:

Preamplifier Controls ...................... 8
4.1 Power ... ............... .. ........ 8
4.2 Headphones ......................... 8
4.8 Volume, Balance ....... . . . ........... 9
4.4 Input Selector ........................ 10
4.5 lnfrasonic Filter ...................... 10
4.6 TapeMonitorland2............. . ..10
4.7 Dubbing 1 and 2 . . . ............... 11
4.8 External Processor .................... 12
4.9 Stereo/Mono ........................ 12
4.10 luneControls ............ .. .. . . . .. .12

Tone On/Ofi ........................ 13
Ski-[7.1214112 ........... ........13
40 Hz/Loudness ..................... 14
4.11-3dBTr'un... .. ................... 14
4.12 Outputl-15 dB ...................... 14
413 Speakers Oif ......................... 14

5.0 PEAK UNLIMITER

Dynamic Range Expander . ............... 15
5.1 What ItDoes .................... 15
5.2 The Controls ......................... 15

6.0 AUTO-CORRELATOR

Noise Reduction System .................. 15
6.1 What It Does ......................... 15
6.2 The Controls ........................ 16

AutOvCorrelator OnlOff ............... 16
Correlation - Automatic Threshold ..... 16
Correlation Threshold - Manual ..... .16
LF Cal ........................... , 16

7.0 SONIC HOLOGRAM

Stereo Image Processor ................... 17
7.1 WhatItDoes ............ .. .. ...17
7.2 Makin$l Holography Work:

Contro ing Reflections ........ . . . . . .17
Speaker Placement ................... 18

Dealing with Reflected Sounds . . . . . . 18

7.3 Making Holography Work:
Finding the Stereo Axis ........... . . . . .20
7.4 Making Holography Work:
The Controls ......................... 21
Sonic Hologram Generator On/Ofl' ...... 21
Holographic Listening Angle
(RearPanel) .. ....... ......... 21

Hologra hic Injection Ratio:
Norm hecretical ..... . . . , . , , , 21

7.5 Learning to Hear
theHolographicImage.,.......... ....22
7.6 EffectsofSpeakerDesign...............23
77 Patent Notice ......................... 23
3.0 TIME DELAY

Ambience Reproduction ....... . ......... 24
8.1 What It Does ......................... 24
8.2 Cheesing Loudspeakers

for Amblence ......................... 24

8.3 Psychoacoustics
and Speaker Placement ................. 25
8.4 Using More Than
'lwo Ambience Speakers ................ 25
8.5 Connections . . . . ................... 26
8.6 The Controls ............. , , ,. 26
9.0 Appendix A:

The Theory of Sonic Holography .......... 28
9.1 The Illusion of Stereo Perspective ...... 28
9.2 Stereo Recording and Playback ...... . . 29
9.3 Sonic Holography:

Cancelling Acoustic Crosstalk ....... . . 30

10.0 Ap endjx B:

In use of Difficulty ..................... 30

10.1 Hum ............................... 30

10.2 Radio-Frequency Interference . ...... ..31

10.3 Problem-Solving: Diagnostic Hints ....... 33

Block Diagram ...................... 32

10.4 Specifications ........................ 34

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ln order to select the best value oi preamp input
capacitance, you first must determine the total capa-
citance recommended for the cartridge. (See the manu-
factiners specifications or refer to magazine reviews.)
Then subtract the capacitance which is contributed
by the phono signal cables and tonearm wiring of your
turntable. (Again, check the makers specifications,
test reports, or as a last resort assume a typical value
of 150 pF.)

What remains is the value of input capacitance which
should be added by the preamp input; set the PHONO
1 LOADING switch to the nearest value. (There is no
need to match the computed value of capacitance ex-
actly: with most cartridges a variation of 50 or 100 pF
from the ideal value produces only a very slightchange
in tasponse.)

Example: the Stanton 8818 cartridge is designed for
a 275 pF load, and a Pioneer turntable has A cable
capacitance of 100 pF; 275 minus 100 equals 175pF,
so sei. the PHONO 1 LOADING switch to 180 pF.

An alternative approach is to set the capacitance by
listening to recordings Typically, with too lowacapa.
citance the uppetAmidi-ange (the soprano voice range)
will be sof " while the response at the highest fre-
quencies will be peaky, leading to increased surface
noise and edgy violin tone. Too much capacitance will
bring the upper-midrange forward and roll off the ex-
treme highs,

3.2 GROUND

If your turntable is equipped with a separate
ground wire, try connecting it to the ptearnplifiers
GROUND pwt and note whether this connection
minimizes hum. II it does, make the connection
permanent. If you have two turntables, try connect-
ing both ground wires to the GROUND post.

Normally these are the only connections made
to the GROUND post. All other components in the
stereo system are grounded through their signal
cables, and if you connect additional grounding
wires among stereo components the result will be the
formation of ground-current loops and anincreased
hum level.

In some systems it may prove beneficial to con-
nect a wire from the preamplifiers GROUND post
to a true electrical earth ground such as a cold-water
pipe; see the separate chapter on Hum.

3.2 TUNER INPUTS

Connect the signal cables from an PM or FM/AM
tuner to these jacks. If your tuner has both fixed
and variable output jacks, it usually is preferable
to use the variable jacks. Then you can adjust the
tuners Output Level control so that, when you
switch from Phono to Tuner, the volume level of
the sound is approximately the same.

3.4 AUX 1 and AUX 2 INPUTS

Connect any other line-level" signal sources to
these jacks. Examples include a TVsound tuner, a
separate AM radio tuner, the output of a spare tape
machine used only for playback but not recording,
the output of a separate microphone preamp or
mixer, etc. Note: if you want to connect the sound
signal directly from an operating television set, first
check with a TV service technician to be sure that
the sets circuitry is isolated fiom the AC power line
via a power transformer. In general, console and
projection TVs are safe in this respect, but some
portables are not.

3.5 TAPE 1 and TAPE 2 INPUTS

You can connect cables from the linelevel play-
back outputs of two tape recorders to these jacks,
The output jacks may be identified as LINE OUT,
PLAY, or MONITOR, If you are using a separate
tape noise-reduction system (Dolby, DBX, etc.)
with a recorder, then the recorders outputs will be
connected to the processor; in this case it is the pro-
cessors playback outputs which should be connect
ed to the C-4000s Tape Inputs.

If you are connecting two tape recorders it nor-
mally makes no difference which is connected to
TAPE 1 and which to TAPE 2.

If your tape recorder is equipped with 2 DIN live-
pin input/output socket as well as conventional phono
jacks, make connections to the phono jacks; usually
these will provide the best match to the 04000 in
terms of impedance, sensitivity, and minimum noise.
If the recorder is equipped only with :1 DIN socket,
then you can obtain an adapter cable with a DIN plug
on one end and phono plugs at the other for connec-
tion to the 04000.

3.6 EXTERNAL PROCESSOR INPUTS
These jacks enable the connection of any of a
large range of signal processing accessory devices.
Examples include:
o A graphic equalizer or parametric equalizer.
o A dynamic noise filter, impulse noise suppressor
(tick-and-pop filter), or scratch filter.
0 A dynamic-range expander, compressor, or limiter.
o The special equalizer unit supplied with some
loudspeakers, notably certain models from Bose,
ElectroVoice, KLH, and Infinity. Altemntlvely,such a