Carver C 1 Service Manual

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C-I SERVICE MANUAL

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UA.R.NI NG
Any person performing these procedures will be exposed to
HAZARDOUS VOLIAGES AND RISK OE'ELECTRIC SHOCK

It is assumed that any person who removes the COVer from
the unit has.been properly trained in'protecting
him/herself from avoidable injury. Therefore, the
procedures described herein are to be performed by

QUALIFIED ELECTRONICS SERVICE PERSONNEL ONLY

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This manual was designed and developed by
Carver Corporation -
and
P. Kurt Schmidt
lnstructicnaJ Media Designs. Seattle, Hashinguum

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CARVER CORPORATION MODEL C~l SERVICE MANUAL. SET 2

1 .0 Introduction

This service manual covers the technical information needed to service
the CARVER. MODEL C~1 SONIC HOLOCRAPHY PREAMPLIFIBR. Anyone using this
manual must be skilled in reading schematic and technical diagrams, and
should be fully proficient in using standard tools of the electronics trade
for troubleshooting and repair.

Refer to the more general C-l Owners Manual for information regarding
any of the following topics:

C-l Features and Controls-

Theory of Sonic Holography

Making Holography work

Effects of lloudSpeaker Placement and Design
Acoustic Troubleshooting of Sonic Holography
General Problem Solving and Troubleshooting

This manual is designed to address two primary areas of concern
encountered when a Model C-l is brought in for repair:

A. Themanual contains those critical-test procedures and expected
results necessary to determine whether or not the unit is
functioning as intended by design.

8. The manual provides diagnostic methods for locating the offending
circuit element(s) once a valid malfunction has been detected.

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CARVER COEPOIATIOH MODEL C-l SBRVICE MANUAL

6 .4 Line A-plifier

A) Pre-set controls and reference per steps 6.1 and 6. 3 above.

B) Verify that the LINE AMP GAIN is between 16.0 and 17.0dB.

C) Verify that CHANNEL IMHALANCE is:

1. less than 0. SdB with volume control fully clockwise

2. less than 2.5dB with volume control turned counter-clockwise
until signal at output is dewn 50:18. Return volume control to
fully clockwise position.

D) Disconnect one of the input cables, and use a shorting plug to short
that input to chassis ground. Verify. that SEPARATION at the output
is greater than 45dB. Remove shorting plug and re-connect input.

E) Sweep signal frequency from 20 Hz to 20th:. and verify at each output
that FREQUENCY RESPONSE is between 40.0dB and -0.3dB.

F) Verify that DISTORTION is less than 0.052 at ZOkI-lz and ZOHz with

2Vrms output into a minimum load of 10k-ohms using an 80k1-Iz filter
for RFI suppression.

6.5 Balance Control
A) Pre-set controls and reference per steps 6.1 and 6. 3 above.
B) While rotating BALANCE control thrOughout its range, verify that each

output reaches at least -70dB of attenuation and never exceeds '+0.SdB
of gain.

6.6 Hono Switch
A) Pro-set controls and reference per steps 6.1 and 6.3 above.
8) Set STEREO switch to IN position ("MONO"), and verify that the
INSERTION GAIN of each output is between -0.3 and +0.3dB. -
C) Disconnect one of the input cables and use a shorting plug to short
that input to chassis ground. Verify that the INSERTION GAIN of the
driven channel is down -7. 0 to -8. OdB. Rs-connect input. '

6. 7 Speaker Switch

A) Pro-set controls and reference per steps 6.1 and 6.3 above.
B) Set SPEAKER switch to IN position ("OI-1"). and verify that each
output is down by at least -70dB. '

6.8 Turn-On Delay
A) Pre-set controls and reference per steps 6.1 and 6.3 above.
15) Set POWER switch to OUT position ("OFF").
C) wait at least 5 seconds.

D) Set rowan-switch to m position (0N) and verify that each output
is below ~30dB for at least 6 seconds.

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