PHONIC XP3000
PROFESSIONAL
HIGH-FIDELITY SOLID STATE POWER AMPLIFIER
Once in a generation
the audio gods smile upon mankind and inspire audio electronic engineers to
produce an outstanding amplifier that stands out from the hundreds of makes and
models produced for the world at any one point in time.
This page is my
personal testimonial to the Phonic XP3000 two channel rack mounted Class
H professional power amplifier, produced from early 2002. The later black
face model pictured below was produced from about 2007.
To the best of my
knowledge this amplifier remains in current production.
The Phonic range of products is manufactured in Taiwan
and marketed globally by the Phonic
Corporation. The XP3000 is readily available in Asia, Europe and Africa
but not so readily in Australia, where I am located.
The Phonic XP3000 was
only sold in small numbers in Australia so finding one has been a challenge,
but after many years’ of searching for the ultimate hi-fi solid state amplifier
I am now the proud owner of a pair of these fine amplifiers.
Mine are configured
in MONO bridge mode - one Mono bridge mode amplifier for each stereo channel.
The reasons for this are described below.
The dynamic
performance and linearity over frequency with a loudspeaker load is excellent.
Bridge mode offers
half the damping factor of two channel mode, helping the amplifiers to be a
little more "tube" like. In my system, bridge mode sounds obviously
superior to normal two channel mode.
Maximum rms output
voltage in bridge mode is approximately 130Vrms – 200Vp. This capability
presents enormous dynamic headroom for normal home use – at least 100db – and
produces a realistic sound from quality recordings.
Home cinema users
will know that films are now made with huge dynamic effects, particularly at
low frequency. To reproduce this class of signal a very responsive system is
needed to prevent waveforms being chopped off – i.e. compressed. Compression
kills clarity, tone, fidelity and dynamic peaks. Compression is essentially a
form of severe distortion.
WHY THE PHONIC XP3000
?
To my ears,
comparative listening tests revealed there is little difference in sound/tone
quality between the various makes and models of Class AB solid-state amplifiers
when playing CD’s or vynil recordings or bass guitar.
The traditional
"harsh" transistor sound is always present, which is why audiophiles
and guitarists often prefer tube/valve amplifiers.
Much can be done to
improve aural reproduction quality and the listening experience with the use of
Graphic Equalisers, Tone Controls and choice of loudspeakers however, to my
ears, there is a profound improvement in tone from solid state amplifiers with
Class H operation compared to Class AB designs.
Audio amplifiers are
much more than just electronic performance specifications. Functionality,
mechanical design and construction, component and wiring layout, protection
systems, cooling systems, serviceability and general appearance are important
elements.
Cooling fan noise
level is an important limiting factor for home hi-fi installations - excessive
noise disqualifying many otherwise good sounding commercial amps from in-home
use. Check before you buy.
The XP3000 is quiet –
not silent but quiet enough for home use
There is nothing more
devastating to a live show performer than loss of sound mid-performance, hence
reliability is critical. Reliability and maintainability become increasingly
more important after the manufacturer’s warranty expires and the device ages
from wear and tear. Component quality, access and reliability determine
long-term operation and service life.
Many modern
amplifiers are typically "throwaway" items because repair costs
typically exceed the new cost price to the importer/distributor. It is common
for some manufacturers to scrap amplifiers returned under warranty because it
is cheaper to scrap rather than incur local labour rates plus parts. It is
definitely not economical to return an amplifier to the manufacturer overseas
for service.
Some popular brand
local agents or distributors do not keep spare printed circuit boards because
there is little demand for them after model runout, so when an amplifier
several years old or more fails the consequence may be scrapping and
replacement. I have experienced this several times with different makes and
models.
Due to frequent model
changes, manufacturers generally keep custom designed spares such as OEM
printed circuit boards and IC’s for only a few years after production ceases
and warranty periods expire or until stocks run out. Some name-brand
manufacturer local distributors/agents do not carry spares at all. Regardless
of original cost, uneconomically repairable amplifiers must be scrapped. Choose
carefully.
I have also
discovered through hard experience that modern surface mount component
technology is beyond the capabilities of some service technicians and the
result has been destruction of printed circuit boards through faulty repair.
In my case, my Phonic
XP3000 amplifiers are about 20 years old and spares may not be readily
available, however many of the components are industry standard and I have
opted to take the risk. I remain confident because some of my other solid-state
amps are up to forty years of age and still performing well. The Peavey
industrial quality MKIV (400W) introduced in 1981 and Firebass 700 (700W)
introduced in 2001 Class AB mono Bass Heads stand out.
Ultimately it is what
an amplifier sounds like and how well it performs that determine its fitness
for purpose.
The widely copied
industrial grade Crest CA series is a fine example of the Class H genre that
set an industry standard for design and performance.
For example, the
Crest CA12, Peavey CS3000, EV P3000 and Phonic XP3000 have similar electronic
specifications.
However the Phonic
XP3000 has four quiet cooling fans with two front and two rear for efficient
heat transfer. Unfortunately the Crest CA12 and Peavey CS3000 both have two
rear noisy cooling fans, rendering both unsuitable for home stereo application.
I have no info on the EVP3000 fans. My lesser powered amps all have noisy fans.
Equivalent amplifiers
from other manufacturers will of course have a variety of different attributes.
Classes G, H and TD
use various electronic schemes to provide a variable + and – DC rail voltage to
the Class AB power stage of an amplifier – the object being to increase
amplifier efficiency and reduce mains power consumption for large
installations. Due to the extra complexity and production cost of Classes G, H
and TD systems they are used generally in amplifiers having power outputs of
1,000 watts or more (bridge mode mono), where the lower cost of mains
electricity will, over time, offset the higher initial capital cost.
The Phonic XP3000 has
a two tier power supply. Some makers use three or four tiers. For my needs two
are adequate.
A full explanation of how Class G/H amplifiers work is
presented at https://peavey.com/c/Power-Amplifiers-in-Bridge-Mode
and
https://www.sound-au.com/articles/class-g.htm
The more recently
introduced popular Class D amplifiers offer lower cost and weight and higher
efficiency. The genre has attracted both supporters and detractors. My
personal experience with a Class D amplifier has been with a "hi-fi"
stereo that sounds awful. Independent reports from pro-audio sound system
engineers tell me their experiences with Class D amplifiers have been
disasterous. Some reports suggest that when a Class D amplifier fails it takes
the speaker out with it. In contrast, some folks are enthusiastic about their
Class D amplifiers. So consider risk when selecting Class of amplifier.
I have no interest in
including a Class D amplifier in my personal system.
However Class D
amplifiers are here to stay and will become progressively more popular as
prices reduce over time.
SELECTION PRINCIPLES
It is worth reminding ourselves that no-one builds the perfect
amplifier, so there will always be examples of fine amplifiers delivering
failure and disappointing performance.
Reputable manufacturers can still produce the odd poorly engineered
model or deliver equipment with manufacturing defects. That is why they offer
guaranties and warranties.
This is particularly
relevant to "brand-name engineering" practices, where well known
manufacturers buy ready-made products from a third party supplier then place
their own brand name and logo on them.
Placing blind faith
in an established name brand supplier is not always the best option. Do the
research before buying. It does not follow that one person’s experience will
satisfy your requirements. Where possible, always try before you buy.
Consider the need for
reliability and cost of service or replacement.
It should be noted
that the higher the power output the greater the risk of massive damage or
self-destruction of amplifier and speakers if something goes wrong. Murphy’s
Law says "if something can go wrong it will."
Note that ALL wires
or devices that carry current will ultimately fuse when overloaded.
Big is not always
better. It might be wiser to use several lower powered amplifiers and speakers
than a single high power system.
The usual approach is
to match the amplifier to the speaker power rating however, regardless of
amplifier power rating, the more speakers and speaker power headroom over
amplifier power output the better because acoustic efficiency improves and
speaker distortion is reduced.
Finally, consider
mains supply limitations. In Australia that means 2400 watts with a 10A socket
and 3600 watts from a 15A socket. Check the amplifier specifications.
The amplifier current
draw should be added to other equipment such as Tuners, Preamps, CD players,
Cassette Decks etc when calculating maximum safe operating current.
MY JOURNEY TO SUCCESS:
My journey into Class
H configured audio amplifiers began when I needed to pull my trusty tube stereo amplifier out of service
for a complete upgrade and rebuild.
That amplifier was
the result of 30 years’ research and development and is nearly as far as I can
go without spending megabucks on output transformers.
It is a personally
custom-designed and constructed two-channel stereo amplifier that features six
x 6146 beam power tubes per stereo channel connected in pentode connection,
supplied by four independent solid-state power supplies – common B+ to Plates,
common B+ to Screen Grids, common B+ to voltage amplifier/driver stages, common
fixed bias supply, common AC heater supply to 6146’s, and common AC heater
supply to 5692 voltage amplifier/driver tubes. All power supplies are solid
state bridge mode with PII filters. Filter caps are very large.
It is my intention to
completely rebuild the amplifier as two separate mono rack mounted units, each
with eight x 6146 or 6883 tubes connected as four pairs in parallel push-pull
pentode mode.
The design is
essentially based upon the GEC 400W
KT88 design with cathode-follower driver stage, but modified with my OESTEX Optimised Electron Stream © technology
principles.
The amplifier was
originally intended to use GEC KT88 tubes but a set of 12 tubes cost a great
deal in 1979, so it started its life with 6CA7/EL34 power tubes instead
(because I had some on hand) in Ultra-linear mode - but they oscillated
frantically and drove our dog nuts when the amp was switched on. The industrial
quality 6146’s solved the problem – and look better.
Using 6146 tubes in
Ultra-linear mode is not convenient because the Screen Grids cannot be run at a
useful Plate voltage, so Pentode mode it had to be. The McIntosh MC3500 MKI and
MKII amplifiers solve this with an additional winding on the output
transformer. I did try using a separate transformer for the Screens Grids
backfeeding from the main OT secondary, but that did not work well at all.
The 6146 and its
variants deliver a powerful clean sound, especially when supported by quality
output transformers and adequate power supply. The vital element to success
with them is the application of my OESTEX Optimised
Electron Stream © technology principles. I prefer the black Plate RCA tubes
to grey Plate alternatives.
The existing
Ultra-linear mode tube output transformers were custom designed and
manufactured for me in 1979 and use multiple interleaved windings on double C
Cores. They are rated at 100W rms continuous. The four independent 4 Ohms
interleaved secondary windings provide output impedances of 4, 16, 36 and 64
Ohms when series connected.
My multiple driver
series-connected speaker system present a 64 Ohms load to each channel of the
stereo tube amplifier – no problem with matching output transformers - but can
present real challenges to a solid state amplifier because they need a higher
output voltage to drive them. The 64 Ohms number is simply the sum of the
speaker voice-coil impedances I had on hand at the time.
The speakers are
configured as a vertical array in installed in a transmission line cabinet and
have a combined total nominal power rating of 100W rms per cabinet.
In my system the
series speaker connection produces a distinctly superior sound to standard
parallel connection.
The two reasons for
this are that series-connected speakers sound better (to my ears) than parallel
connected speakers (with both tube and solid-state amplifiers) AND the lower
the secondary to primary turns ratio in the Output Transformer the better the
inductive coupling, efficiency and performance. For any given Output
Transformer primary load impedance, a 64 Ohms load presents one sixteenth the
impedance ratio and one quarter the turns ratio as for a 4 Ohms load, thereby
improving current transfer from primary to secondary windings.
MY QUEST TO FIND A REASONABLY IDENTICAL SOUNDING SUBSTITUTE SOLID-STATE
AMPLIFIER
For my notional
requirement of a comfortable 200W rms
per stereo channel into 64 Ohms load (to match the tube amp under
reconstruction) the amplifier must deliver an output voltage of at least
113Vrms and 160Vp.
That spec takes us
into the realm of a powerful solid state amplifier at the usual loads – i.e.
3192 W rms into 4 Ohms per channel !!!!. (unless an impedance matching
transformer is used).
To test alternative
configurations in a conventional two-channel stereo mode, I reconfigured the
speakers from their existing series connected 64 Ohms load into parallel
connected mode to present a 4 Ohms load to various single rack cased
two-channel solid-state Class AB
amplifiers. The system sounded awful and had a very harsh tone.
This is due to the
different combination of resistance, capacitance and inductance in the speaker
circuit interacting with the amplifier power stage and negative feedback
system.
Next I installed a 1
kW toroidal impedance matching transformer between the amplifier and 64 Ohms speakers
to present a low value load to the amplifier. The sound lost clarity.
Next I installed an
EI hi-fi matching transformer in the same configuration with similar result.
The only option left
was to consider bridge mode in the amplifier – but that requires one two
channel amplifier to be connected in mono mode for each channel – i.e. two
amplifiers are required for stereo.
So that was done and
the results were significantly better and worth pursuing further.
At this point the two
channels had different make and model amplifiers installed and they were not
evenly matched.
WHICH BRIDGE MODE AMPLIFIER?
Peavey describe Bridge-Mode as follows:
Having determined
that bridge mode was the way to go, the next step was to determine which brand
and model amplifier sounded best in bridge mode.
It turned out that
all of my many Class AB solid state amplifiers sounded much of a muchness
because they all have similar power stage configurations – typically
2SC5200/2SA1943 transistors configured in one to six pairs per channel.
For comparison, the
similar specs Crest CA12 has six pairs of power transistors and the more
powerful CA18 model seven pairs plus Mosfets.
Also, the Peavey CS3000 has 8 pairs 2SC5200/2SA1943 transistors per
channel plus an NPN transistor network for the Class H high rail control. Rated
power is 3,050 watts @ 1 kHz at <0.1%
T.H.D. @ 4 ohms
However I found that
each of my Class H amplifiers sounded significantly better than any Class AB
amplifier I have used.
Returning to the
power discussion above it can be seen that a 100 watt nominal system requires
up to 1,000 watts at 40 Hz, depending upon speaker system SPL across the
frequency range.
1,000 watts rms per
channel amplifier is a mighty beast.
The solution lies in
the fact that Class H amplifiers are only produced commercially in high power
models – nominally 500 watts (e.g. Phonic XP1000) and more per channel –
because of their complexity, additional circuitry and components
But when we divided
1,000 by 10 = 10X, being the typical proportionate power reduction caused by
the increase in speaker impedance at 40 hz from its nominal at 400Hz, we still
get 100 watts per channel at 40Hz – more than adequate for any home stereo
installation.
CLASS H AMPLIFIERS
For a comprehensive
description of Class H operation see https://sound-au.com/articles/class-g.htm
and https://peavey.com/c/Power-Amplifiers-in-Bridge-Mode
Despite pro-amplifier
industry power output ratings with 2 Ohms loads (voice or program) for Class H
amplifiers, to ensure long term reliability I would not run any make or model at
less than 4 Ohms load in stereo/parallel mode or 8 Ohms bridged mono mode.
Consider also losses in the mains supply and speaker connecting cables when
operating with a 2 Ohms load. The difference in loudness between rated power
with a 2 Ohms load or 4 Ohms load is at best 3 db – typically less than 3 db.
In an AC (or DC)
electrical circuit, maximum usable power (energy flow) is achieved when the
load impedance is equal to the source impedance, because the voltage across
each half of the circuit is equal.
Consider the solid
state amplifier is a generator having an extremely low internal impedance. Thus
to attain maximum power transfer the load must present an extremely low
impedance – i.e. less than One Ohm.
Damping Factors of up
to 500:1 at 4 Ohms load are now common, suggesting the amplifier output
impedance is about 0.002 Ohms – well below normal standard speaker impedances.
Loads of this order
represent a short-circuit to the amplifier terminals and should be used only
with great care – or not at all. Even 2 Ohm loads represent a challenge to many
amplifiers. However as explained below, a 4 Ohms load in bridge mode results in
twice the voltage output hence the current is proportionately less for the same
power output as a single channel, so temperature rise in the power transistors
will be proportionately less – unless the amplifier is driven beyond that
equivalent power output or to its limit.
Unlike tube
amplifiers, where power output is essentially linear over the practical range
of frequency dependent variable speaker impedance loads, solid state Class AB
amplifiers suffer from power reduction inversely proportional to load increase
– i.e. double the load impedance = half the power output. Four times the load
impedance = one quarter the power output etc.
They also suffer from
the characteristic that through current and therefore temperature rise in the power
stage devices increases disproportionately to reduction in load impedance –
i.e. Watts = I˛R.
This characteristic
means the primary limiting factor for power output at low impedance loads is
the current flowing through the power transistors, whereas with high impedance
loads (e.g. 70V line or 100V line loads) the limiting factor becomes the output
voltage.
The limiting factor
for maximum power output is whichever occurs first – voltage or current.
However, to produce
the highest power output the load must be minimal, thereby maximising through
current and heat dissipation in the transistors.
Reputable
manufacturers usually publish specs for comparative methods used to calculate
and measure power output but this approach has numerous difficulties because of
the many variables. The smart user will regard ratings established under
controlled test conditions as a guide only.
Unfortunately many
commercial solid state power amplifiers will not handle high through current
for prolonged periods, so are rated for "music programme" or
"programme" or "peak" or EIA "short burst" watts
instead of the traditional tube rating system of continuous watts rms. The
consequence of this rating method is that the real world continuous rms power
output is somewhat less than the rated value.
It can be seen from
manufacturers’ specifications that in many cases rated amplifier power at 4
Ohms load is not twice that for an 8 Ohms load, and 2 Ohms load is not twice
that for a four Ohms load. This is an indicator of excessive temperature rise
and/or power supply limitations.
The Phonic XP3000
suffers a little from this non-linearity but I cannot detect it aurally at my
normal listening power levels – and that’s what matters. One must sometimes
compromise. It could be however that with the 64 Ohms load the load
characteristic is different to 2 to 8 Ohm loads.
Returning to through
current in the output stage, it follows that the more parallel transistors used
the less the current through each device, thereby increasing reliability because
the load is shared so the power stage will run cooler.
It also follows that
the higher the maximum rated output voltage the more linear the output power
will be in response to load variation – i.e. power output is less effected by
load impedance because the power stage and power supply are less stressed.
It should be noted
that the load presented by a speaker will never be less than its DC resistance
and typically within the range one to 10 times its nominal impedance rating.
Therefore we can expect the load on typical music program material to vary by a
factor of 10 times across the full audio frequency range.
Therefore our ideal
amplifier will be capable of a high output voltage and a high output current
with minimal power change across the range of loads – i e. “linear”.
The design conclusion
must be that for any given amplifier design there will be an ideal operating
range of load where the inversely proportional output voltage (high voltage-low
current) and current (high current-low voltage) characteristics intersect.
That approach means
that if we want high fidelity and high reliability we will automatically
require an amplifier having a power output considerably greater than the
nominal load power requirement.
A second important
issue is that it is common to see commercial amplifiers become unstable at
minimal loads – typically 4 Ohms minimum load.
Another factor is
that with a 2 Ohms load, power losses in long speaker leads/cables are
significantly higher. Just 1 Ohm of total (both legs) resistance in the speaker
cable will result in a 50% loss of power in the cable.
The result is that
conventional industry practice is to rate amplifiers for a 4 Ohm minimum load.
Operating below this can void the manufacturer’s warranty.
All the above becomes
important with sustained signals, such as bass guitar and organ.
One modern method of
rating amplifiers for "programme" power is to use an algorithm to
mathematically determine an “average” rms power equivalent by analysing a
pre-determined programme signal waveform then converting it to rms.
Consequently rated "programme watts" will be rms watts x a multiplier
factor – always resulting in a higher number than rms.
Practical experience
tells us that for satisfactory performance bass guitar amplifiers and supporting
speaker systems need to have a power output of up to ten times the rated power
output of a tube lead guitar amplifier. This ratio may need to be increased in
certain venues.
e.g. for balanced
sound levels and depending upon speaker efficiency, a 40 watt guitar amp may
need to be supported by a 400 watt solid state bass amp supported by
appropriate speakers. Hard to accept but that is reality.
The reason is partly
because of the human ear characteristic, partly because bass speaker impedances
may increase to 8 to 10 times nominal in the frequency range 120 to 40 Hz as
the impedance rises inversely proportional to the frequency, partly due to the
bass waveform being closer to a sine wave than other instruments and partly due
to the difference between tube amp rms rating and peak solid state amp rating.
That means to
maintain an equivalent level SPL (loudness) power output in the bass range
compared to mid-range, the amplifier power output must increase by the square
root of the power ( Watts = I˛R ) x the change in R (speaker load impedance) as
the speaker impedance rises.
i.e. if the speaker
impedance increases from 4 ohms in the mid-range to 40 Ohms at 40 Hz, to
maintain a flat response curve the power output must increase by the reduction
in SPL (decibels) for each frequency amplified – i.e 10 times for 10 db gain or
100 times for a 20 db gain.
Most bass playing
occurs in the fundamental frequency range of 40 to 160 Hz (4 octaves) so the
demands on amplifier and speaker are very different to requirements for voice
and most other common musical instruments.
Consequently an
amplifier that is pushed too hard will simply fail due to excessive current in
the output stage – often spectacularly.
Over-temperature
sensing devices installed on the power transistor heatsinks are simply too slow
in live music situations where sustained signals are used. It takes time for
heat to conduct through a transistor case then into a heatsink to a sensor
The same principles
apply to both the musician and home hi-fi system – often worse in the home
because smaller speaker systems are used.
So in my situation of
having need for an amplifier that will produce a clean 100 watts per channel
stereo into a 64 Ohms nominal load – increasing to nominally 480 Ohms at 40 Hz -
it is the case that a conventional Class AB solid state amplifier that produces
maximum rated power at 2 or 4 Ohms load, will not deliver much power at 480
Ohms nominal.
The Phonic XP3000 in
bridge mono mode will deliver more than 250W rms into 64 Ohms and 35W rms into
480 Ohms, so is an ideal match for my needs and system design choices.
With a 6 db boost at
40 Hz from a Graphic Equaliser, the response figures become 250W at 40Hz and
60W at midrange x 2 channels – still very loud in the home environment and more
than my 100W rms speakers can handle.
BRIDGE-MODE MONO SYSTEM CONFIGURATION
Bridge-mode mono changes the output circuit from “unbalanced” to
“balanced” form.
Balanced bridge-mode
mono requires the two separate channels of a two channel amplifier to be
reconfigured to each act as one half of a push-pull pair.
The input circuitry
is reconfigured by a simple switch on the rear panel of the amplifier and the
output cables are connected differently.
In a conventional
Class A or AB amplifier with balanced output, one side of the output is live
and the other grounded.
However in
bridge-mode mono the two speaker cables are each “floating” with the centre
point grounded internally within the output stage. Each terminal is therefore
“floating”.
The disadvantage of
this is that the speaker cables are floating above ground so can act as an
antenna to feed spurious hum and noise signals back into the amplifier – i.e.
signals that can pass through the RF filter in the output stage. Ungrounded
speaker cables can also cause instability when they are positioned in close
proximity to audio cables and other equipment. Speaker metal frames cannot be
easily grounded to improve system stability.
Musical instruments
are particularly vulnerable to this effect.
But when we connect
in bridge-mode MONO we double the number of power transistors and double mono
power output.
CHOICE OF CLASS H
AMPLIFIER
My choice is the
Phonic XP3000 because it has all of the attributes I need to support my
listening requirements in the home hi-fi situation.
As noted above most
amplifiers use cooling fans too noisy for home hi-fi installation. But the
Phonic XP3000 is fine. Not zero fan noise but very low SPL.
At 24.2 kg net weight
it is challenging to handle. Two units require strong cabinet and shelf.
The XP3000 is 150 mm
high nominal. The cabinet housing should provide at least 25 mm vertical
clearance for cooling and an open or ventilated back for air flow.
The Phonic XP3000
uses 16 BJT power transistors per channel in the lower tier Class AB output
stage supplied with + - 100VDC plus 14
more MOSFETS per channel in the upper tier Class H section supplied with an
additional + - 60VDC - i.e. + - 160VDC
total rail voltages.
So when the XP3000 is
configured in bridge-mode mono, it uses
32 power transistors (2SC5200/2SA1943) in the Class AB mono power stage plus 28
Power MOSFET transistors (1RFP260N) in the Class H section.
This XP3000
configuration results in an electronic scheme whereby the current though each
pair of power transistors is only one eighth the total.
But because the two
channels and therefore transistors are connected in series when in bridge-mode mono mode, the audio signal
POWER produced by each series quad set is twice that for single channel output.
The DC rail voltage
across each power transistor remains the same as that for the standard two
channel mode resulting in bridge-mode
mono mode producing twice the audio signal voltage output as for
conventional operation.
This configuration
results in a situation where, for any given level of power output and load
impedance – e.g. 8 Ohms - the through-current and heat dissipated by each power
transistor will be only 70% of that when in normal two channel parallel or mono
mode, resulting in significant improvement in reliability.
An important XP3000
feature is that the power stage is driven by an additional pair of
2SC5200/2SA1943 transistors per channel. This is a big plus because some
brand-name amplifiers use driver transistors that are too lightweight and tend
to fail when driven to higher power levels. I have lost several amps from
failure of the driver stage.
Overall the design and construction may be regarded as “industrial”
quality.
THIS IS AWESOME !!
SOUND QUALITY AND TONE
Of all the solid state
amplifiers I have tested and compared over the past twenty years the Phonic
XP3000 stands out from the pack.
It delivers clean,
crisp sound with excellent dynamic response and realistic reproduction with a
quality superior to any other amp tested.
In my opinion the
tonal characteristic is similar to a beam power tube amplifier.
There is a small
presence of the typical “transistor” sound but it is of a low order and not
intrusive.
The frequency
response is very wide with crystal clear highs and strong deep bass.
The XP3000 sounds
superior to my other Class H amplifiers.
Ultimately hi-fi
audio is a trade-off between competing priorities, wants and preferences.
So for the audiophile
who wants power with clarity, the XP3000 can be purchased in good used condition
for an affordable sum.
My amplifiers are
from the first batch in 2002 and have the grey front panel.
The later model has a
black front panel but is otherwise identical.
The standard model
features selectable high–pass filters at 30 and 50 Hz to roll-off unwanted LF
signals if required to protect speakers – refer to the User Manual for details.
There is a model
variant, the XP3100, which provides additional switchable LF low-pass filtering
at 60, 90 and 120 Hz for sub-woofer applications, but is otherwise identical.
Another variant is
the XP3000B, which appears to be identical to the XP3100.
For full details and
features refer to the User Manuals and Service Manuals linked below.
CONCLUSION:
IMHO the Phonic XP3000 is a mighty amplifier worthy of consideration for
applications within its ratings.
Of course there are other makes and models that could be competitive or
even better but for my needs and sound preferences the XP3000 is my favourite.
Ultimately, as with any product, it is a case of “to each his own”.
IMPORTANT:
To get the best
result for home hi-fi, it should be used in bridge-mode mono with a minimum
load of 8 Ohms.
As shown by my own
installation a load of 64 Ohms does not represent a challenge to this amp in
standard or bridge mode, however I would claim it sounds better in bridge mode.
Note the maximum
rated output voltage is approximately 130Vrms – 200Vp
MANUALS
YOU TUBE
VIDEOS
https://www.youtube.com/results?search_query=phonic+xp3000+amplifier
INTERNAL
VIEWS:
The Phonic
Corporation
https://en.wikipedia.org/wiki/Phonic_Corporation
Since its inception in 1972, Phonic has become a
leading manufacturer of professional audio products—permanently perched on the
cutting edge of both analog and digital technology. By the early ’80s, Phonic
was the number-one producer of DJ mixers, supplying over 85% of the total units
sold worldwide. Phonic didn’t stop there. Since then, Phonic has expanded its
manufacturing expertise into all areas of professional audio. We deliver
products including digital mixers, audio analyzers, precision speakers, and
wireless technologies that give the sound engineer industry-leading usability,
performance, and dependability. Phonic's global reach extends across 50
countries and we proudly manufacture our products in 100% owned, ISO-certified
factories.
About me:
For more than sixty
years, within my means and capabilities, my quest has been to pursue two
separate but inter-dependent streams of audio system research and development
activity to fulfil my personal goals:
·
to create my ultimate
home hi-fi system
·
to create my ultimate
personal bass rig
My audio system experience
includes design, construction and use of tube based home hi-fi, musical
instrument amplifiers, public address amplifiers and professional sound systems
comprising tube and solid state equipment.
In addition to my
tube audio experience, over the past 35 years I have personally owned, used,
serviced, refurbished and upgraded numerous solid-state
amplifiers, including mono PA amplifiers, stereo power amplifiers and
receivers, surround sound home cinema amplifiers, guitar amplifiers and bass
amplifiers in home and live performance applications.
Rated stereo/two
channel power outputs of those solid-state amplifiers range from 10 watts per
channel to 1,400 watts per channel into 2 Ohms and rated bridge mode mono power
outputs ranged up to 2,800 watts into 4 Ohms.
I have also received
independent reports from professional PA system and service engineers who have
offered impartial experience based opinions on the performance and reliability
of different makes and models of amplifiers and classes of operation they have
used.
My tube amplifier
website is at https://www.oestex.com/tubes/
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This page is at https://www.oestex.com/xp3000/
For information on Tube Amplifiers – see https://www.oestex.com/tubes/
Contact:
Dennis Grimwood
Email: contact (copy and paste)
Location: Perth,
Western Australia,
AUSTRALIA