NuPrime STA-6 User manual

STA-6
Class A+D Stereo Amplifier Bridgeable
into a 160 watt Mono Amplifier
COMMERCIAL

01
FCC Notice - Declaration of Conformity Information
T
his equipment has been tested and found to comply with the limits for a Class B digital device, pursuant t
o
p
art 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmfu
l
i
nterference in a residential installation. This equipment uses and can radiate radio frequency energy and, i
f
n
ot installed and used in accordance with the instructions, may cause harmful interference to radi
o
c
ommunications.
H
owever, there is no guarantee that interference will not occur in a particular installation. If this equipmen
t
d
oes cause harmful interference to radio or television reception, which can be determined by turning th
e
e
quipment offand on, the user is encouraged to try to correct the interference by one or more of the
f
ollowing measures:
•Reorient or relocate the receiving antenna.
•Increase the separation between the equipment and receiver.
•Connect the equipment into an outlet on a circuit different from that to which the receiver is
connected.
•Consult the dealer or an experienced radio/TV technician for help.
W
ARNING: Only peripherals complying with the FCC class B limits may be attached to this equipment.
C
hanges or modifications made to this equipment, not expressly approved by us or parties authorized by us
c
ould void the user’s authority to operate the equipment. This device complies with part 15 of the FCC Rules
.
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peration is subject to the following two conditions: (1) This device may not cause harmful interference, an
d
(
2) this device must accept any interference received, including interference that may cause undesire
d
o
peration.
N
otice for customers: The following information is only applicable to equipment sold in countries applyin
g
E
U Directives.

02
E
U Declaration of Conformity
H
ereby, NuPrime Audio, Inc. declares that this device is in compliance with th
e
e
ssential requirements and other relevant provisions of Directive 2004/108/EC.
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he manufacturer of this product is NuPrime Audio, Inc., 1712 Pioneer Ave. Ste 1817, Cheyenne, Wyoming
8
2001, USA
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he Authorized Representative for EMC and product safety is NuPrime Audio, Inc., 1712 Pioneer Ave. Ste 1817,
C
heyenne, Wyoming 82001, USA.
F
or any service or guarantee matters please refer to the addresses given in separate service or guarantee
d
ocuments.
F
or customers in Europe
D
isposal of Old Electrical & Electronic Equipment (Applicable in the European Union and othe
r
E
uropean countries with separate collection systems)
T
his symbol on the product or on its packaging indicates that this product shall not be treated a
s
h
ousehold waste. Instead it shall be handed over to the applicable collection point for the recyclin
g
o
f electrical and electronic equipment. By ensuring this product is disposed of correctly, you will hel
p
p
revent potential negative consequences for the environment and human health, which coul
d
o
therwise be caused by inappropriate waste handling of this product. The recycling of materials wil
l
h
elp to conserve natural resources. For more detailed information about recycling of this product
,
p
lease contact your local Civic Office, your household waste disposal service or the shop where yo
u
p
urchased the product.

03
Safety Instructions
T
here are two categories of Safety Instructions included in this manual:
•Product Warnings, (i.e., what must never be done to assure avoiding those hazards that could caus
e
bodily injury or property damage); and
•User Directions (i.e., what must always be done to assure the safe use of your device).
T
he Safety Instructions contained in this manual have been categorized in accordance with the seriousness o
f
t
he potential hazards through the use of Signal Words. Those Signal Words, and their intended meanings, ar
e
a
s follows:
D
ANGER: Indicates that a failure to observe the Safety Instructions could result in death or catastrophi
c
b
odily injury.
W
ARNING: Indicates that a failure to observe the Safety Instructions could result in serious bodily injury.
C
AUTION: Indicates that a failure to observe the Safety Instructions could result in minor bodily injury o
r
p
roperty damage.
N
OTE: Designates important information that relates to activities and/or conditions that might result in los
s
o
f data and/or damage to your device.
S
afe Use and Operation of Your Device
T
his equipment emits stray RF energy and will interfere with the reception of signals by airborne electroni
c
n
avigational devices or medical devices. Do not operate this equipment near any sensitive medical devices.
W
ARNING: Use only grounded AC power cords.
A
lways immediately disconnect the power to the equipment in the event the device emits an unusual odor o
r
s
ound or generates smoke.
W
ARNING: Never attempt to disassemble, repair or make any modification to your device. Disassembly
,
m
odification or any attempt at repair could cause bodily injury or property damage, as well as damage to th
e
d
evice itself.

04
W
ARNING: Your device is not a toy. Never allow children to play with your device. Misuse, rough or imprope
r
h
andling of your device by children could result in serious bodily injury for any of the enumerated safet
y
w
arnings in this manual. In addition, always keep all accessories and components out of the reach of smal
l
c
hildren as small parts might present a choking hazard. Seek immediate medical attention if choking occur
s
o
r if any small part has been swallowed.
C
AUTION: Never raise the sound volume level too high when using your device with earphones. An excessiv
e
s
ound volume level could cause damage to your hearing.
W
ARNING: To reduce the risk of fire or electric shock, do not expose the unit to moisture or water.
D
o not allow foreign objects to get into the enclosure. If the unit is exposed to moisture, or a foreign objec
t
g
ets into the enclosure, immediately disconnect the power cord from the wall. Take the unit to a qualifie
d
s
ervice person for inspection and necessary repairs.
R
ead all the instructions before connecting or operating the component.
K
eep this manual so you can refer to these safety instructions.
H
eed all warnings and safety information in these instructions and on the product itself. Follow all operatin
g
i
nstructions.
D
o not use this unit near water.
Y
ou must allow a minimum 10 cm or 4 inches of unobstructed clearance around the unit. Do not place the unit
o
n a bed, sofa, rug, or similar surface that could block the ventilation openings. If the unit is placed in a
b
ookcase or cabinet, there must be ventilation of the cabinet to allow proper cooling. Keep the component
a
way from radiators, heat registers, stoves, or any other appliance that produces heat

05
T
he unit must be connected to a power supply only of the type and voltage specified on the rear panel.
C
onnect the component to the power outlet only with the supplied power supply cable or an exact equivalent
.
D
o not modify the supplied cable.
D
o not route the power cord where it will be crushed, pinched, bent, exposed to heat, or damaged in any way
.
P
ay particular attention to the power cord at the plug and where the cord exits the back of the unit.
T
he power cord should be unplugged from the wall outlet during a lightning storm or if the unit is to be lef
t
u
nused for a long period of time.
I
mmediately stop using the component and have it inspected and/or serviced by a qualified service agency if:
•The power supply cord or plug has been damaged.
•Objects have fallen or liquid has been spilled into the unit.
•The unit has been exposed to rain.
•The unit shows signs of improper operation.
•
The unit has been dropped or damaged in any way.

06
B
ackground
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uPrime is not a Switching Digital Amplifier
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witching Digital Amps, commonly known as Class-D, first appeared some decades ago. From the start,
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lass-D showed enormous potential along with significant shortcomings: limited usable bandwidth, and a
fi
xed saw-tooth waveform for audio- signal modulation, the latter producing jitter that effectively masks
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ow-level signals.
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nstead of the conventional saw-tooth configuration, NuPrime’s patented circuit design uses a naturally
o
ccurring analog-modulating signal that adds neither noise nor jitter. Rather than reverting to off-the-shelf
s
olutions, NuPrime’s in-house advances have further unlocked the switching amp’s potential without the
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ifficulties pure digital-switching amplifiers simply cannot avoid – in other words, the best of both worlds.
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nce upon a time heat and bulk were badges of status. Today, they’re the bane of obsolescent technology.
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uPrime amps switch at 500,000Hz – more than 10X the CD sampling rate. At these frequencies,
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ransformers and capacitors work far more efficiently, making it possible to reduce their size. Typically,
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lass-A amps rarely utilize more than 30% of the power they draw; the rest is wasted as heat. High operating
t
emperatures also shorten the useful life of the electrolytic capacitors used in abundance in these designs.
A
comparison with traditional designs is mind-boggling. A NuPrime amp, small enough to sit on the palm of
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ne’s hand, is, typically, 85% efficient – in practical terms, cool-running and easy on the utility bill.

07
A
dvantages of NuPrime Amplifier Technology
1
.High bandwidth. Truly faithful reproduction of music demands bandwidth, and plenty of it. Inadequate
bandwidth withholds important spatial information and tonal complexities. NuPrime amps deliver high
bandwidth with a ruler-flat response from 20 to 50,000Hz. Only a very few, very expensive linear
amplifiers are capable of achieving that. This bandwidth allows NuPrime to amplify complex music with
faithfulness far beyond the capability of conventional amps, with particular regard to a vast soundstage –
accurate spatial information delivered in full.
2
.An extremely high damping factor. Damping factor is simply a measure of an amplifier’s ability to drive
and control a speaker. The higher the number, the better. An excellent tube amplifier might have a
damping factor between 10 and 100. A high-quality Class-A amplifier might reach 200. A NuPrime
amplifier has a damping factor about 400. And unlike conventional amps, NuPrime’s damping factor is
totally unaffected by changes in audio frequencies. Simply stated, NuPrime delivers lightning-fast
dynamics to any speaker.
3
.No phase shift. Many amps use output filters that create phase shift. When phase shifts, spatial
information becomes inaccurate. Most amps present phase shifts of better than 45 degrees at 20 kHz,
heading toward 90 degrees as frequency increases. NuPrime amps cancel these distortions owing to a
unique closed-loop design producing zero phase shift across all frequencies. Repeat, zero.
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uPrime provides unequalled, fully regulated output without ripple voltage or noise. Absent this electronic
s
mog, music emerges from a pristine background, delicate details and nuances intact. Purity has a sound, and
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t’s beautiful.

08
I
ntroduction
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he NuPrime STA-6, a 2 X 90W Class A+D stereo amp, bridgeable into a 160W mono amp, is designed with
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nhanced even-order harmonic circuitry that produces sonic characteristic similar to NuPrime STA-9, but
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eaning toward neutral with a slight hint of warmth. The STA-6's spacious, transparent, dynamic and
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uxuriously textured soundstage has to be heard to believe.
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he STA-6 amplifier is derived from the Single End Class A Module + Class D design first introduced in the
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TA-9. By joining a powerful high impedance singled ended amplifier circuit in the preamp stage with a well
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ntegrated Class-D power stage, the STA-6 offers the richness of Class A sound with the remarkable speed
a
nd clarity of NuPrime Class-D design. Audio enthusiasts are bound to be impressed.

09
T
he NuPrime amp circuit improves on traditional Class-D design by using a self-oscillating circuit to generate
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ulse-width modulation. The amplifier switches at a frequency of 500kHz, well beyond the compact disc’s
4
4.1kHz sampling rate. Most class-D amps switch at 300kHz or lower. A new low noise switching power suppl
y
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s designed specifically to complement the STA-6 amplifier. The overall result is unprecedented transient
s
peed, smooth with lots of details and an almost shocking level of dynamic impact.
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he STA-6's frequency response to 50 kHz elevates vocals into emotional experiences; similarly, instrumental
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pper registers mimic a live performance’s shimmering heights.
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he STA-6 is designated for NuPrime Commercial product line and it is designed to be highly reliable under
n
o-load condition and enhanced short circuit protection.
S
pecifications:
•Inputs: RCA: Un-Balanced input x 1
•Outputs: Stereo Speaker Out x 1 or Mono Speaker Out x 1
•Power: 2 x 90W / 1 x 160W @ 8 & 4 Ohms. Same power at 8 & 4 Ohms as the output power is
limited by the power supply.
•Input Impedance: 47k Ohms
•Gain: x 28
•Signal to Noise Ratio: > -90dB at 1W, 10W, 100W
•THD+N: 0.01% (Stereo) / 0.01% (Mono)
•Frequency Response: 10Hz to 50kHz
•Worldwide AC voltage: 100 VAC～240 VAC
•Dimension: 200 mm W x 184 mm D x 60 mm H (including feet)
•Weight: 1.6 kg
•Color: Black