Coil Audio CA-286 Operating instructions

CA-286
INSTALLATION GUIDE
&
OPERATING MANUAL
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Table of Contents:
Page1- High Voltage warnings and considerations
Page2 - Package Contents
Page2 - Changing Transformers
Page3- Controls Description
Page4 - Circuit Block Diagram
Page4 - Module Illustration
Page5- Maintenance
Page6 - Warranty Information
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FOR YOUR PERSONAL SAFETY, PLEASE READ THIS OPERATING
MANUAL THOROUGHLY BEFORE USING THIS PIECE OF
EQUIPMENT.
Please note the following:
->Be aware that the 10pin cinch sockets at the rear of the PS6 tray back block are
live at 275V whenever the unit is powered on. Don't place hands, or anything else on
unused tray slots, or nearcinch connectors when in use.
->Never plug in a CA-286 module while the PS6 Power Supply is on.
->Never operate a CA-286 module without the protective cage covering the circuit
board assembly.
->Neverswap transformers ona CA-286 module while the PS6 Power Supply is on.
->This unit must be installed in such a manner that operator access to the Main AC
plug is maintained and accessible. To reduce risk of electric shock, it is essential that
the unit is powered off and/or disconnected from Main AC power before any
installation or maintenance procedures begin.
->This equipment is not to be mounted in an area prone to excessive vibration (like a
drum riser or sub cabinet) or high SPL sound levels. Doing so could introduce
unwantedartifacts and can damage the unit.
->This equipment is not intended for use in hazardous environments. It must be used
and stored in studio conditions, such that the ambient relative humidity does not
exceed 80%, nor is the temperature to be allowed to drop to a level which would
cause excessive moisture buildup in the unit.
->Please insure that adequate ventilation is provided and that the PSU chassis and
any installed PS6 MODULE ventilation slots are not obstructed. When rack mounting
this equipment in a tightly sealed space, a small fan may be required to provide
sufficient airflow.
->In the event that this unit has been dropped or has suffered any impact damage, an
electrical safety test must be carried out by a qualified technician or shipped back to
Coil Audio LLC for service before reconnection to the Main AC power. Please do not
attempt to service the unit yourself.
WARNING!
HIGH VOLTAGES PRESENT!
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INSPECT PACKAGE CONTENTS
All CA-286 modules are carefully packed for shipment to insure a safe arrival.
However, if there is any damage, contact Coil Audio immediately and keep any and
all shipping materials for use during any possible damage claims with the shipper.
Included in the Package are:
(1) CA-286 module
(1) 1 -3 input/output transformers depending onorder
(1) Guide Brackethardware set for PS-6 Tray that includes:
-(4) GUIDEBRACKET plates (two short/two long)
-(4) 3/8" #6-32 Stainless Steel Screws w/Lock-Nuts
-(2) Fender Washers
-(2)Module Thumbscrews
GUIDEBRACKETS MUST BEINSTALLED BEFORE INSTALLING MODULES IN
THE RACK TRAY
CHANGING TRANSFORMERS
Before inserting modules into the rack tray, make
sure both your input and output transformers are
firmly seated into the module body. Never plug or
unplug transformers while the module is plugged in
and powered on.
Each octal plug has a guide pin to ensure proper
orientation, refer to the adjacent picture for
placement. The front octal socket is for the input
transformer (such as CT-110 or CT-100HN). The rear
octal is for the output transformer (CT-41).
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For guide bracket and module installation please see Pages 3-4 of the "PS6 Rack
and Power Installation and Operating Manual"

CONTROLS DESCRIPTION:
-HI+ TILT:
The -HI+ tilt switch interacts directly with the NF,transitioning
from a gentle filtering of upper frequencies to the natural
openess of the EF86s. The +2 position removes all filtering,
while the "-" positions add a gentle broadcast type hi
frequency roll off. Most effective when the NF knob is
between 11:00 and 5:00, The more Negative Feedback, the
more reactive.
Stock position is 0or 12:00
-LOW+ TILT:
The -LOW+ tilt knob boosts and cuts lowerfrequencies in the
Negative Feedback Loop, dimensionally boosting and moving
the low end from front to back in the soundstage. Most
effective when the NF knob is between 11:00 and 5:00, The
more Negative Feedback, the more reactive.
Stock position is 0or 12:00
INPUT:
Next to the phase reverse switch, is a 5-position attenuation
network of 'Balanced H-pads' that go between the mic and
input transformer. The first four positions are for 150 ohm
microphone inputs and are 0, -6, -12, and -19 db. The final
Line (LN) position is for any balanced line level signal such as
tape machines, daw outputs, other preamps, etc.
Stock position is 0
OUTPUT:
The OUTPUT control knob is placed between the first and
second tube stages. It sets the final level and offers further
manipulation of the two-stage gain structure.
Stock position is +42or 5:00
NF or NEGATIVE FEEDBACK:
Turning the "NF" knob counterclockwise reduces the amount
of Negative Feedback, brightening and moving the sound
forward while heightening harmonics and sensitivity. It also
raises totalgain from 42 to 60db. Turning it clockwise
increases the amount of negative feedback, producing a
darker tone with a smooth harmonic structure.
Stock position is 3:00
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1 2
3
-12
-6
-19
0
LN
-12
-6
-19
0
LN
1:10
Input
Transformer 1st Stage EF86 2nd Stage EF86
Output
Transformer
Output
Attenuator
Negative Feedback
Network
Input
Attenuator
Input
Transformer
Output
Transformer
Output
Attenuator
Phase
Reverse
Switch
4:1 12
3
Two Stage Single Ended Parafeed Circuit Block Diagram
Input
Transformer
Output
Transformer
Output
Attenuator
+LOW- Tilt
Negative
Feedback
Input
Atten
uator
+Hi- Tilt
Module
Cage
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Maintenance:
Tube Replacement: 2 x EF86/EF806/6267/E80f
To replace tubes, turn off power supply, and allow
modules to cool down and discharge in the tray for at least
ten minutes. Capacitors in the module can store high
voltages if removed too quickly, and not allowed to
discharge after power down.
After discharge, remove module and disconnect top
cage from module base by removing the four screws on
the side. Firmly grab tube and pull straight up to remove it,
taking care not to damage other components. When
inserting new tubes be sure pins are straight and aligned
before inserting into the tube socket. The socket should
be a tight fit, some pressure is required to insert new
tubes.
TURN OF POWER SUPPLY AND ALLOW MODULE TO COOL
AND DISCHARGE CAPACITORS FOR AT LEAST TEN MINUTES
BEFORE ATTEMPTING TO SERVICE OR REPLACE TUBES.
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Warranty
For repair orservice please contact us at: [e-mail]
All Coil Audio products carry our 1-year limited warranty and are hand-built,
assembled, and tested in the USA using UL-approved parts.
Limited 1-Year Warranty
During the warranty period, Coil Audio will, at no additional charge, repair or
replace defective parts with new parts. This warranty does not extend to any
Coil Audio product that has been damaged or rendered defective as a result
of accident, misuse, or abuse; by the use of parts not manufactured or
supplied by Coil Audio; or by unauthorized modifications. NOS Vacuum tubes
are exempt from the 1-year warranty, but are warrantied for 30 days from
date of purchase.
Except as expressly set forth in this Warranty, Coil Audio makes no other
warranties, express or implied, including any implied warranty of
merchantability and fitness fora particular purpose.
Warranty & Non-Warranty Repair Service
If your Coil Audio product is in need of warranty service or repair, please
contact us at [e-mail] make sure to put the Serial
Number(s) of the product(s) needing repair in the ‘Subject’ field of the e-mail
and leave a description of the issue with your unit(s). Coil Audio is not
responsible forany shipping expenses to orfrom our repair facility.
If your Coil Audio product is no longer under warranty - a nominal flat bench
fee that includes diagnostic and repair will be charged along with the price of
any individual components replaced. If the issue is vacuum tube related we
may contact you directly for resolution. At the owners discretion,
replacement NOS Vacuum Tubes will be charged market value (depending on
availability) ora New Model substitution can be made at the time of repair.
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Coil AudioPO BOX 4324 Lawrence KS, 66046
www.CoilAudio.com