JC 3
Phono Preamplifier
OWNER’S GUIDE
Table of Contents
Introduction
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
4
5
Placement and Ventilation Guidelines.
AC Voltage Selection
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
6
Audio Input and Output Connections
7
Other Connections on your JC 3
.
.
.
.
.
.
.
.
.
.
.
.
8
Rear Panel Controls
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
9
Front Panel Operation
10
11
12
13
Frequently Asked Questions
If You Require Assistance or Warranty Repair
Specifications
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
3
INTRODUCTION
Thank You for Choosing Parasound
Your new Parasound Halo JC 3 Phono Preamplifier is the pinnacle of analog audio technology
and value engineering. It is legendary designer John Curl’s latest design, carrying on a proud
tradition of phono preamp designs dating back to the 1970s.
We are proud to offer you this exceptionally versatile audio component, knowing that it will bring
you many years of enjoyment and dependability.
We appreciate you taking the time to read these instructions and thank you for selecting
Parasound. For updates and corrections to this manual, we invite you to check our web site,
Enjoy.
The Parasound Staff
Keeping Records for Future Reference
Record the serial number located on the back panel or bottom of your JC 3 in the space below.
Also note your Parasound Dealer’s name and telephone number. Your purchase receipt/bill of
sale is required to determine if your JC 3 is eligible for Parasound warranty service. We
recommend that you make an extra copy of your original purchase receipt/bill of sale and store it
inside the JC 3’s carton.
Parasound JC 3 Phono Preamplifier Serial #:
__________________________________________________
Parasound Dealer:
________________________________________________________________
Parasound Dealer Phone Number:
__________________________________________________________________
Date of Purchase:
________________________________________________________________
Important Warranty information
There is no Parasound warranty for this unit if it was not purchased from an Authorized
Parasound Dealer. Investigate warranty coverage statements made by an unauthorized dealer
very carefully, as you will need to depend entirely upon your dealer, and NOT upon Parasound.
Unauthorized dealers lack the capability to make repairs or arrange for repairs of Parasound
equipment. A list of Authorized Parasound Dealers and detailed warranty information is available
time.
A missing or altered serial number could indicate that this unit was re-sold by an unauthorized
dealer or is stolen merchandise. If this unit is missing its serial number or the serial number has
been altered, you should return it to your dealer immediately for a full refund.
4
Unpacking Your JC 3 & Placement Guidelines
Unpacking Your JC 3
Carefully remove your JC 3 from its shipping carton and locate all the enclosed accessories:
• AC power cord
• Two trigger wires, one with 3.5 mm mini plugs, one with a 2.5mm and a 3.5mm mini plug
While you are unpacking your JC 3, inspect it thoroughly for possible shipping damage and tell
your Parasound dealer immediately if you find any. If possible, save and store both the inner and
outer cartons and–most especially–the foam packing inserts, to protect the JC 3 if you have to
move it or ship it. You may wish to flatten the cardboard cartons to save room in storage after
cutting the taped seams on the bottom flaps. This would be a good time to make a copy of your
sales receipt to store with the JC 3’s original packing.
Placement Guidelines
The JC 3 will be easier to use and will last longer if you follow these simple guidelines:
ƒ
ƒ
Place the JC 3 on a shelf that will adequately support its weight.
Use input and output cables that are long enough to leave some slack; that will enable
you to pull the JC 3 out of a cabinet to check or to change connections without
inadvertently disconnecting cables.
ƒ
ƒ
ƒ
If you’re putting the JC 3 in a cabinet, it needs a space that’s at least 22 inches wide so
you’ll be able to turn it around for access to its rear panel connections.
Place your JC 3 where you can route input and output signal cables as far as possible
from any AC cords.
Where signal cables must cross AC cords they should do so only at a 90° right angle.
Ventilation Requirements
• Always position the JC 3 horizontally.
• We recommend that you do not place the JC 3 above a power amplifier.
• Do not install the JC 3 in an unventilated equipment cabinet or compartment. Pockets of
stagnant hot air can build up even in a cabinet with an open front and back. A ventilation
fan such as the Parasound Zbreeze is highly recommended to prevent “hot spots” in
confined spaces.
Rack Mounting Your Parasound JC 3
With its four feet removed, the JC 3’s front panel height occupies two rack spaces: 3.5" or 88.2
mm. (A single standard rack space occupies 1.75" vertical space.) For mounting in a standard
19” equipment rack, you must use the Parasound HRA 2 rack mount kit (purchased separately).
The HRA 2 kit includes four bolts and eight plastic washers with raised “shoulders.”
Slide one washer onto each mounting bolt with its raised shoulder pointing toward the panel hole.
Carefully insert the bolt through the hole and slide the other washer on the bolt with its raised
shoulder facing the rear side of the panel. The washers will sandwich the JC 3 panel and the
four mounting bolts to prevent metal-to-metal contact between the JC 3 chassis, the equipment
rack, and the other components mounted in the rack.
Note: Tighten each bolt just enough to keep the unit secure in the rack to avoid deforming the
shoulder washers. Eliminating metal-to-metal contact reduces the likelihood of creating a ground
loop that might introduce hum into your system.
5
AC Voltage Selection
115v / 230v AC Voltage Selector Switch
This switch is found on the underside of the chassis. Make sure the 115/230V switch is set for the
correct AC line (mains) voltage before you plug in the JC 3’s AC power cord.
Note: The JC 3 could be seriously damaged if AC Voltage Selector switch is set
incorrectly.
Prior to plugging your JC 3 into an AC power source, check the position of the 115v/230v
switch on the JC 3’s chassis bottom and do not depend on the 115v or 230v markings on
the carton.
The 115V setting is correct for North America where the JC 3 can operate safely with AC line
voltages between 110-120v. Most other countries will require the switch to be set to 230V. With
the 230V setting the JC 3 can operate safely with AC line voltages between 220V-240V.
Always turn off your JC 3 and disconnect its the AC cord before making or changing
any input, output or trigger wire connections. Inserting or removing an input or output cable
while the JC 3 and your preamp and power amplifiers are turned on can result in a blast of sound
that can damage your loudspeakers. Make sure there is no strain or tension on any cables that
could cause them to pull loose.
6
Connecting your JC 3
Always disconnect the AC cords to your JC 3 and power amplifier(s) before making or
changing any input, output or trigger wire connections. Inserting or removing an input or
output cable while the JC 3 or power amplifiers are turned on can result in a blast of sound
that can damage your loudspeakers. Make sure there is no strain or tension on any cables
that could cause them to pull loose.
Audio Input Connections
Connect your turntable’s signal cables to the Input jacks on the JC 3. It is a good idea to
oxidation on them. The turntable’s ground wire attaches to the JC 3 Ground terminal that is
located between the two channel inputs and outputs.
Important Note: Turntables and phono preamps are very sensitive to electromagnetic fields
that can cause audible hum. To minimize hum follow these guidelines:
•
•
Place your turntable as far as possible from power amplifiers or power line conditioners.
Run your turntable signal cables as far as possible from power amplifiers or power line
conditioners.
•
•
Do not run the turntable signal cables parallel with any AC cords.
Wherever the turntable signal cord must cross AC wires they should cross at a 90o right
angle.
•
It might be necessary for you to experiment with the exact positioning of the turntable
signal cables to minimize hum.
7
Audio Output Connections
The JC 3 Output Jacks connect to the input jacks on your line level preamplifier. Each JC 3
module has two Output jacks, one Balanced XLR jack and one Unbalanced RCA jack. The
balanced and unbalanced jacks are active simultaneously. If your preamplifier is equipped
with balanced inputs we recommend using the JC 3 Balanced XLR output jacks for best
possible signal-to-noise ratio and best rejection of external noise sources.
Note: The JC 3 uses a fully differential balanced output circuit and does not employ phase
inverters. The JC 3 does not invert polarity.
Each channel module has a 3 position input load switch. Select the setting that matches your
turntable cartridge type. If you are unsure which setting is best for your equipment you might
want to contact the cartridge manufacturer. You may also try all three settings and use the
setting which sounds the best.
ƒ
ƒ
The MM setting is for moving magnet cartridges. It provides a 47k ohm load and
appropriate gain for all MM cartridges.
The MC 100 Ω setting is for most moving coil cartridges. It provides the higher gain
required for low output or high output MC cartridges with a 100 ohm load that is ideal
for nearly all MC cartridges.
ƒ
ƒ
The MC 47k Ω setting provides the appropriate gain for MC cartridges with an
alternative 47k ohm load. You can try both the 100 Ω or 47k Ω settings to see which
sounds best in your system.
The MC 47k Ω setting is also the recommended load for MI (moving iron) cartridges,
such as Grados.
Other Connections
12V In Jack
The JC 3 12V input uses a mono 3.5mm sub-mini jack. To automatically trigger the JC 3 on
and off, insert the trigger wire plug into this jack and plug the other end into your
preamplifier’s 12V trigger output jack. When the JC 3 Turn On Options switch is set to 12V
the JC 3 will turn On and Off with your preamplifier.
If the preamplifier’s trigger output is a + and - terminal, you can cut the 3.5mm plug off one
end of the included trigger wire and strip off about ¼” (6mm) of insulation. Attach the bare
wires to the + and - terminals. The conductor with the white stripe on its insulation
corresponds to the plug’s tip (+) and the conductor with the unmarked lead corresponds to
the plug’s “sleeve” (-).
Note: The Model JC 3 trigger circuit draws a negligible 15 mA from the preamplifier.
12V Loop Out Jack
The Trigger Out jack lets you loop or “daisy-chain” the incoming trigger voltage to another
component.
AC Power Cord
The IEC standard AC cord supplied with your JC 3 is an audiophile-grade component.
Please connect it directly to an AC wall outlet or power conditioner that is always “live.” If
possible, plug your JC 3 into the same AC outlet that your preamplifier is plugged into. If
different AC outlets are used for the JC 3 and the preamplifier the ground potential may be
higher or lower between the outlets, resulting in audible hum.
8
Rear Panel Controls
Turn On Options Switch
For your convenience, there are two ways the JC 3 can be turned on and off.
Manual: Use the front panel On-Off button
Auto: When the Turn On Options switch is set to the auto position, the JC 3 is turned
on and off with an external +9 V to + 12 V voltage from your preamplifier. When
the external voltage ceases the JC 3 will turn off immediately. When the Auto
Turn On switch is set to Auto the front panel Power button is disabled.
Input Load/Gain Switches
Each Left and Right channel module has a 3 position load/gain switch. Select the setting that
matches your turntable cartridge type. If you are unsure which setting is best for your
equipment you might want to contact the cartridge manufacturer. You may also try all three
settings and use the setting which sounds the best.
.
ƒ
ƒ
The MM setting is for moving magnet cartridges. It provides a
47k ohm load and the appropriate gain for all MM cartridges.
The MC 100 Ω setting is for most moving coil cartridges. It
provides the higher gain required for even very low output MC
cartridges with a 100 ohm load that is ideal for nearly all MC
cartridges.
ƒ
The MC 47k Ω setting provides the appropriate gain for MC
cartridges with an alternative 47k ohm load. You can try both
the 100 Ω and 47k Ω settings to see which sounds best in your system.
The MC 47k Ω setting is also the recommended load for MI (moving iron) cartridges,
such as Grados.
Note: The JC 3 load options are restricted by intent. Designer John Curl believes that the
most satisfactory playback of LP records depends on the elimination of compromises; complex
input loading options are counter to this philosophy.
AC Polarity Switch
The JC 3 Polarity switch inverts the “hot” and “neutral” conductors of the incoming
AC power. It does not affect the 3rd pin ground connection. In most cases the AC
Polarity switch should remain in its Normal position. Occasionally, the only way to
reduce or eliminate hum when listening with a phono preamp is to invert, or reverse
the phase, of the phono preamp’s hot and neutral conductors.
Note: Please turn off the JC 3 and unplug its AC cord before changing the
setting of the AC Polarity switch.
AC Power Switch
This switch is provided to turn the JC 3 completely off when it will not be used for an
extended time. Normally, this switch is left in the “on” position (upper section is pressed in).
9
Front Panel Controls
On-Off Button
Push once to turn on the JC 3. There will be a slight delay as the circuits stabilize and the DC
servos settle down. When the JC 3 is turned on the blue glow around the On-Off button will
be brighter and the red P badge will glow brighter. Push again to turn off the JC 3.
Mono Button
Press the Mono button one time to parallel the stereo channels to mono. Press a second
time to return to stereo. Older mono records and stereo records with high levels of rumble will
sound cleaner when you select mono on the JC 3. The Mono button will glow blue when
stereo is selected and amber when mono is selected.
Design Overview
John Curl’s phono preamps are legendary. His approach to amplifying extremely low level
signals gives the listener the best chance to experience the full emotional content of the
source. In the JC 3 the physical implementation of the circuits closely follows the actual
circuit topology and the layout is as compact as possible to minimize pickup of external noise.
The preservation of low level signals is achieved by separating the critical audio signals from
the non-audio circuits and non-audio wiring. Each channel has its own circuit board and each
channel is fully enclosed in its own extruded aluminum “vault.” This vault shields the
sensitive circuits from the JC 3’s power supply and from external sources of noise.
The power transformer is an R-core type, which shares the advantages of a toroid
transformer for minimizing radiated hum. However, it is far superior to a toroid transformer in
preventing noise carried on the AC power line from passing through to its secondary
windings and into the power supply.
A second level of shielding separates the phono vaults from the power supply, power
transformer and even the transformer wires running to the AC inlet on the rear panel. This
shielding consists of two partitions of 3/8” low carbon “mild” steel to prevent any
electromagnetic radiation from reaching the phono modules. The rear panel of the JC 3 is
made of aluminum to prevent any electromagnetic interaction with the sensitive phono
circuitry.
Finally, the JC 3 has an on-board AC line conditioner to filter out high frequency noise and
distortion that may be present on your AC power line. This eliminates a potential source of
noise before it ever reaches the JC 3 power transformer. The resulting extremely low noise
levels enable musical nuances to emerge from an utterly silent background.
10
Frequently Asked Questions
Why won’t the JC 3 turn on when I press the On-Off button?
- Check the setting of the Turn On Options switch. It must be set to Manual for the front panel
On-Off button to function.
Why won’t the JC 3 turn on with an external DC trigger?
- Check the setting of the Turn On Options switch. It must be set to Auto for the 12V trigger to
function.
Why is there no sound from the speakers?
- Check that AC is live and the “P” badge and both the On-Off button and Mono button are
illuminated.
- Check that input and output cables are secure at both ends.
I can hear a background hum from the speakers
- Ensure that you have attached your turntable’s ground wire to the ground terminal on the
back panel of the JC 3
- Try changing the postion of the Polarity Invert switch on the back of the back panel of the JC 3
- Move audio cables and AC cords away from each other (while power is off).
- Try to route audio cables and AC cords perpendicular to each other (while power is off).
- Make sure insulating shoulder washers are used if unit is rack mounted.
- Ensure that the power amps and the JC 3 are plugged into the same AC outlet
The sound is distorted and too loud
Are you using an MM cartridge and the JC 3 input load switches are set to MC? Change the
settings to MM.
The sound is weak
Are you using an MC cartridge and the JC 3 input load switches are set to MM? Change the
settings to MC 100 Ω or MC 47k Ω.
When should I use the AC Polarity Invert switch?
If you hear hum and you cannot eliminate it by moving your cables around.
Should I use Balanced or Unbalanced connections?
We generally recommend balanced connections if your preamplifier has balanced inputs.
Recording and broadcast studios use balanced connections almost exclusively because of
balanced lines’ inherent ability to reject noise and hum, even when components are far apart
and connected by long cables. Many high-quality preamplifiers include balanced input
connections with XLR jacks for the same reasons. The JC 3’s balanced outputs enable you to
take full advantage of the inherent noise-rejection capability and superior sound quality of its
precision circuits. Many serious listeners prefer the sonic characteristics of balanced
connections because their lower inherent noise floor contributes to a more defined and
spacious soundstage.
11
Are You Having Difficulty?
Repair or Service
Call your Parasound dealer first. If the dealer can’t help you with your problem we encourage
you to call Parasound’s Technical Service Department, toll-free at 1-866-770-8324, Monday -
Friday, 8am - 4pm Pacific Time. We can suggest other diagnostic tests you can easily
perform.
If we determine that your JC 3 should be returned to Parasound or an Authorized Parasound
Warranty Center for inspection and possible servicing, we will provide the location of a
warranty center near you or shipping instructions for the unit’s return to Parasound.
Before You Return Any Unit to Parasound for Service
Before you send your unit to Parasound, you will need to obtain a specific Return
Authorization (RA) number and shipping instructions from Parasound’s Technical
Department. The RA number must be clearly marked on the outer carton. Use the original
factory packing materials and arrange adequate insurance to cover its value. You must
include a copy of your purchase receipt, since this document establishes the validity of this
unit’s warranty. Warranty repairs are only performed by Parasound or Parasound Authorized
warranty centers when your purchase receipt is from a Parasound Authorized Dealer or
Parasound Authorized Reseller.
Shipments Will Be Refused by Parasound Under the Following Conditions:
1. Unit was sent without the Parasound-assigned RA number marked on the carton.
2. Unit was sent in an unsuitable shipping carton and is likely to have been damaged in
transit.
3. Unit has inadequate packing materials and is likely to have been damaged in transit.
4. Unit was shipped collect for shipping charges. We do not accept collect shipments.
5. Unit was shipped via the US Postal Service.
6. Unit was sent to an address other than the address instructed by our Technical
Department.
Note: The Parasound Technical Department shipping address is not the same as
Parasound’s office address. The Parasound office does not accept packages.
Warranty Repair
Please read your accompanying Parasound Limited Warranty carefully to understand the
applicable rights and limitations. This section provides instructions for obtaining repairs, both for
units covered under the Parasound Limited Warranty and for units or situations which are
outside the Warranty.
Unit is not eligible for repair under the terms of the Parasound warranty if:
1. Unit was not purchased from a Parasound Authorized Dealer.
2. You do not have the original bill of sale or sales receipt from a Parasound Authorized
Dealer.
3. You are not the original owner. The Parasound warranty is not transferable.
4. Unit’s serial number was removed, modified, or defaced.
5. Unit shows evidence of abuse and/or misuse.
6. Unit was modified in any way.
7. A prior repair was attempted by an unauthorized repair station.
12
Specifications
Frequency Response
XLR Pin Identification
1 = Ground (Shield)
2 = Positive
20 Hz - 20 kHz, +/- 0.2 dB
3 = Negative (Return)
THD Distortion: < 0.005% at 20 kHz
AC Power Requirement
115 or 230 VAC 50 - 60 Hz
12 watts
S/N Ratio (MM)
> 86 dB, input shorted, IHF A-weighted
> 80 dB, input shorted, unweighted
Dimensions
S/N Ratio (MC)
Width: 17-1/4” (437mm)
Depth: 13-3/4” (350mm)
Height, with feet: 4-1/8” (105mm)
Height, without feet: 3-1/2” (89mm)
> 75 dB, input shorted, IHF A-weighted
> 70 dB, input shorted, unweighted
Crosstalk: 72 dB at 1 kHz
Weight
Phono Input Impedance
MM setting: 47k Ω
Net: 18 lbs. (8.2 Kg)
Shipping: 25 lbs. (11.4 Kg)
MC setting: 47k Ω or 100 Ω
Rack Mount Accessory
Output Impedance
Unbalanced: < 100 Ω
Balanced: < 100 Ω per leg
HRA 2 (may be purchased separately)
Input Sensitivity at 1 kHz
MM: 4mV in for 1.0V output
MC: 0.4mV for 1.0V output
Total Gain
MM: 47dB
MC: 68dB
Specifications and features subject to change
or improvement without notice.
Copyright Parasound Product Inc., 2010
Rev. 1.0
13
Parasound Products, Inc. 2250 McKinnon Ave, San Francisco, CA 94124
14
|