er equipment review
Gryphon Diablo
Integrated Amplifier
The new Diablo is a big black devil of an
amplifier. No doubt about it. So it’s appropriately named, because Diablo is the Spanish
word for ‘Devil’. As to how an amplifier
that’s entirely designed and manufactured
in Denmark, in the small town of Ry, came
to have a Spanish model name is something
you’d have to ask Gryphon’s founder and
president, Flemming E. Rasmussen. While
you’re at it, you might care to ask him why
it’s so powerful. Rated as able to deliver more
than 800-watts per channel continuously
into 2Ω loads, it’s easily the most powerful
integrated amplifier he’s ever built. Could it
have anything to do with his Poseidon speakers, or the even newer Tridents? I couldn’t
wait to find out…
The Equipment
Power Output: Single Channel Driven
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Australian Hi-Fi
As you can tell even from a quick glance
at the photograph of the front panel, all
functions on Gryphon’s Diablo are controlled electronically, whether it’s direct from
the front panel or from the (fabulously
engineered) infra-red remote. The many
advantages of this approach to design are
well documented, but chief amongst them
in my book is that there’s nothing to become
noisy after several years. True there’s nothing mechanical to wear out, but when you
look at the quality of the mechanical parts
Rasmussen uses inside his other products,
it’s unlikely you’d wear any of them out in
several lifetimes.
Providing solid-state control over volume
is always a little tricky, but Gryphon’s
excelled itself with the Diablo because
the circuit combines a programmable
(in fact, it’s re-programmable, via flash
memory upgrades!) microprocessor that in
turn controls a network of Welwyn ultraprecision resistors that delivers 50 discrete
volume level possibilities in such a way that
at any given setting of the volume control,
only two or fewer resistors are in the signal
path, unlike ‘ladder’ resistor controls, which
can have significant numbers of resistors in
the signal path.
I was instantly drawn to the ‘Mute’
function provided on the Diablo because
I have previously taken issue with the
way this function was provided on earlier
Gryphon
The inside of the Diablo is as much a work of art as the
outside, with state-of-the-art audiophile components
mounted on military specification double-sided PCBs
and almost no point-to-point wiring.
Gryphon amplifiers. I was pleased to find
that in the Diablo, the muting function is
inextricably linked to the volume control so
that it’s impossible to increase the volume
while the muting circuit is active. Not that I
should have been overly surprised, because
over the years I have found Gryphon, more
than any other hi-fi company in the world,
to be extremely responsive to feedback
from consumers and reviewers. Absolutely
every suggestion or criticism is responded
to and evaluated and if Gryphon feels it
can improve the product, it will do so
immediately.
Why should volume and muting
functions be linked? Primarily to prevent
accidental speaker damage that could be
caused if a child, or someone inexperienced
with operating a powerful amplifier, turns
the volume up to maximum while the
muting circuit is on, and then un-mutes the
amplifier. This can cause speaker damage
with even relatively low-powered amplifiers
but in the case of the Diablo, with a
potential 800-watts on tap, it’s an even
more-distinct possibility. However, as I said,
the design of the Diablo’s muting circuit
will mean this scenario can never eventuate.
Input switching is also completely
electronic (via relays you can hear clicking
as you switch between them) and there are
five to choose from, one of which (Input
1) is balanced, via XLR sockets. The other
four are unbalanced, via gold-plated RCA
connectors. Input 4 is designated as the
‘Tape In’ connector, and there’s a separate
‘Tape Out’ so you can loop if you want. As
you’ve probably gathered, no phono stage
is provided on the standard Diablo, but
if you want to use a turntable and don’t
already have an outboard phono stage (and
don’t wish to buy one), you can order one
to be installed in the Diablo as an option. It
has both MM and MC facilities.
The Diablo also has an ‘AV Throughput’
function that allows you to integrate it
with a multi-channel home theatre system
so that the Diablo can drive the two front
channels of a home theatre system without
the need to re-wire or recalibrate your
system when switching between stereo
and multi-channel home theatre operation.
More importantly, you don’t have the
(deleterious) overhead of all the surround
processing in the signal path when you’re
listening to stereo! (Incidentally, I put that
‘AV Throughput’ in quotes because there
just has to be a better description for this
function. I’m open to all suggestions at
[email protected].)
Rather unusually, the Diablo has a
subwoofer output on the rear panel, but
as this simply presents a summed (mono)
line-level signal of whatever input you have
selected—there’s no filtering whatsoever—
calling it a ‘subwoofer’ output is something
of a misnomer. Also unusual (at least for
an integrated amplifier) is the provision of
12v d.c. link inputs and outputs to allow
integration with an automated set-up.
The inside of the Diablo is as much a
work of art as the outside, with state-ofthe-art audiophile components mounted
on military specification double-sided PCBs
and almost no point-to-point wiring. Most
obvious is the absolutely massive Holmgren
toroidal transformer, (Gryphon say’s it’s
‘dual mono’) but nearly as obvious are the
24 4700µF capacitors nestled either side
of it, for a total of 58,000µF per channel.
Obvious by its absence is a cooling fan:
the passive heatsinking of the Diablo is so
efficient a fan isn’t required. In the unlikely
event you are able to drive the Diablo hard
enough to stress it (though I can’t imagine
what you’d have to do to cause this!) there
Brand: Gryphon
Model: Diablo
Category: Integrated Amplifier
RRP: $15,995
Warranty: Three Years
Distributor: Kedcorp Pty Ltd
Address: Unit 8, 529 Parramatta Road
Leichhardt
NSW 2040
T: (02) 9560 4855
F: (02) 9569 1085
E: [email protected]
W: www.kedcorp.com.au
Little-Known Fact
Flemming E. Rasmussen, head
honcho at Denmark’s Gryphon Audio
Designs, may be a great amplifier
designer, but he’s no hockey player.
If he were, he would have known that
one of the most popular hockey sticks
in the world is called the Gryphon
Diablo and (hopefully) named his
newest creation something else.
The two products are hardly likely
to ever be confused with each other
of course, except by web search
engines, where the identical names
make web searches an exercise
in frustration. There is, however, a
plus to it. If you want to see your
audiophile friends turn green with
envy, just tell them you own a
Gryphon Diablo. If you’re a hockey
player, you’ll be able to tell the truth
for just $231!
Power Output: Both Channels Driven
Australian Hi-Fi
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Gryphon Diablo Integrated Amplifier
are several protection circuits that will
actuate to prevent a meltdown. As I noted
earlier, Gryphon rates the Diablo at 800watts per channel into 2Ω, but there are
few speakers whose impedance drops low
enough to allow the Diablo to develop this
power. Claimed power output into 4Ω loads
is 500-watts per channel and into standard
8Ω loads, it’s 250-watts per channel.
One question that many died-in-thewool high-end audiphiles may be asking
at this point is why Gryphon would build a
high-end, high-power integrated amplifier
rather than separate pre and power
amplifiers. Rasmussen’s answer? ‘Integration
of control functions and power amplification
on a single chassis offers crucial advantages
in comparison with separate components.
In separates, the distance between cabinets
introduces exposed interconnects to the signal
path and careful attention must be paid to
electrical and sonic compatibility issues. In a
single-box solution, the audio signal path is
significantly shorter. Any compatibility issues
between preamp and power amp are elegantly
sidestepped, eliminating the need for circuitry
to address these problems. Separate cabinets,
costly interconnects and separate power cords
are no longer necessary, allowing the designer
to allocate a greater portion of the budget
where it counts: in the audio circuit.’
Listening Sessions
Get ready to be tricked by the volume
control ‘buttons’ on the front panel (they’re
actually just triangular up/down icons). I kept
pressing the triangles, when I was actually
supposed to be pressing the small circular
‘dots’ above the triangles. Then, when I
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Australian Hi-Fi
finally trained myself to press the dots, I
discovered that Gryphon appears to have
built variable speeds into the circuit. The idea
behind using variable speeds is great: it’s that
if you need to make a dramatic change in
volume, the rate of change is fast, whereas if
you just want a small adjustment, the rate of
change is slow. I found that if I just held my
finger down I couldn’t quite get the knack
of pushing ‘just so’ and would as a result
often overrun the volume setting I wanted,
so in the end I usually ended up tapping the
control gently with my fingertip whenever
I wanted to make fine adjustments. This
could of course be simply a problem with
my own fine motor skills, so you may have
greater success. Certainly it’s easy to check
out volume control operation in a showroom, and since the volume control’s speed
can be updated via software in any case, it’s
also easily fixed if more people that just me
have issues with it. Remember, too, that in
‘non-review’ situations, it’s likely that you’ll
use the same volume control setting for
every listening session and in this event, the
Diablo will ‘remember’ this level for you and
set it automatically whenever the amplifier is
switched on.
Oddly enough I had no problems at
all with the Input selector, even though
its mode of operation is exactly the same
as the volume control. You can switch
between the five line level inputs, each one
of which can be programmed by you with
a name that reflects whatever component
you have connected to it, so you can leave
the default label (such as ‘CD’) if you’re
happy with that, or change it to read ‘Tabu’
or even ‘Mikado’ (if you have one of these
Gryphon CD players). However, the display
is limited to just eight digits so in some
situations it may be necessary to abbreviate.
Gryphon provides a full character set, so
you’ll be able to be quite creative with your
abbreviations if necessary.
Switch-on is clean, with absolutely no
power-up noises or speaker thumps, even
if the switch-on process is quite slow, at
30 seconds, during which the blue dotmatrix-style display on the front panel
flashes the word ‘Initialising’ at you while
you wait. ‘But wait!’ I hear sharp-eyed
readers cry, ‘That’s more than 8 digits!’ Well
spotted. The display is capable of showing
factory-programmed messages of up to 50
characters over two lines, but the user-input
limit is just eight.
Once operating and thoroughly
warmed-up (which doesn’t take long),
the Gryphon Diablo proved itself to be a
Power Output into 2Ω , 4Ω & 8Ω; with one
and both channels driven.
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Gryphon Diablo Integrated Amplifier
surprised. You can get free tastings at www.
rubbersoulmusic.com.au/mcqueen or www.
mcqueenmusic.com but MP3 doesn’t really
do the sound justice and the pickings are
thin: this is one band that needs to ramp up
its recorded output!
I also listened entranced to the magic of
Walter Gieseking—who was very accurately
described by Bryce Morrison as ‘in every
sense a magician of the keyboard’—playing
Debussy’s Images I & II (EMI Classics). I
simply couldn’t imagine it being improved
upon.
Conclusion
superior amplifier in every respect. There is
absolutely no question of its ability to drive
the most difficult loudspeaker loads, nor of
its ability to drive any pair of loudspeakers,
no matter how inefficient, to ear-shattering
volume levels. I concocted some extreme
loads by wiring several pairs of speakers
in a nightmare mess of series and parallel
combinations and the Diablo didn’t miss
a beat except when I accidentally shorted
the output, upon which it switched itself
off quickly, then with the short-circuit
corrected, powered up again without any
fuss.
Equally there’s no questioning its
musical nature. Everything I played through
the Diablo came out sounding sweet and
truly musical: providing performances that
were as enchanting as they were satisfying,
yet without papering over any deficiencies
in technique on the part of the performers
or the recording engineers. But when both
techniques come together, as they do on
The Idea of North’s CD Evidence (ABC Jazz
981 867-4)…wow! The perfect close (and
wide) vocal harmonising on this CD is
captured to perfection by the Diablo and
given a huge hurry-along by the gorgeously
black background silences that mean there’s
no unwanted texture added to the sound.
The Diablo is also able to keep musical
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Australian Hi-Fi
strands separate yet together—just listen to
the way James Morrison’s Flugelhorn seems
to float ethereally above the meshed vocals,
yet simultaneously entwine with them.
I loved the fact the Gryphon was also
able to capture the joy of making music,
which I found clearly obvious on Lior’s
‘Doorways Of My Mind.’ This CD was
recorded live, and the quality of the sound
leaves a lot to be desired—particularly
the unreal and variable bass—but in the
best tradition of live takes, the vitality of
the night is presented as engagingly if
you’d been in the audience. Lior is one of
those rare artists who makes you want to
experience him live—warts and all—rather
than listen to the perfection of a studio
take. (You can hear samples at www.lior.
com.au.)
Given its prodigious power output, the
Diablo was a walk-up to trial with rock, so
I gave it a try-out with Queen’s Life Support
ICU. Fabulous! That curious screech on the
‘L’ in Leah Duors’ voice every time she sang
the catch-phrase ‘Life Support ICU’ sent
a shiver up my spine every time I heard
it, even when I was prepared for it after
multiple auditions. If you’ve previously
been dismissive of all-girl bands as more
marketing gimmick than music, give
McQueen a listen—and be prepared to be
LAB
REPORT
Ultimately, Gryphon’s Diablo is a contradiction in terms, because the sound it creates is
truly Angelic.
greg borrowman
Readers interested in a
full technical appraisal
of the performance of
the Gryphon Diablo
Integrated Amplifier
should continue on and
read the LABORATORY
REPORT published on
the following pages. All
readers should note that
the results mentioned in
the report, tabulated in
performance charts and/or
displayed using graphs
and/or photographs should
be construed as applying
only to the specific sample
tested.
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Gryphon Diablo Integrated Amplifier
Test Results
Power output was very high, as you can see
on both the bar graphs and in the tabulated
results on the following page. At 1kHz, with
both channels driven into 8Ω, the Gryphon
Diablo delivered 289-watts (24.6dBw) per
channel, 0.7dB higher than specification. At
1kHz into 4Ω loads, both-channels-driven
power output was 503-watts (27.0dBw) per
channel. Into 2Ω loads, output was measured
at 816-watts (29.1dBw) per channel at 1kHz.
You can see on the tabulated results that the
output at 20kHz was measured at 800-watts
per channel, at which point the Gryphon’s
6.3-amp mains fuse blew—hardly surprising
when you consider the current in the output
load at this point was 20-amps and the
amplifier had been running more-or-less continuously at its maximum power output for
several hours. Don’t be tempted to increase
the fuse rating: the fuse won’t fail when
the amplifier is used to play music through
loudspeakers, even those with a nominal impedance of 2Ω. I was very impressed by the
Diablo’s performance in the power output
tests. Note particularly how the amplifier
is able to maintain its high output at the
frequency extremes, with the exceptional
performance down at 20Hz proving that the
Diablo’s power supply is more than up to the
task. The fact that the ‘both-channels-driven’
results are so similar to the ‘single-channel-driven’ indicates that the supply is fully
regulated and that the toroidal transformer’s
performance is exceptional.
The Gryphon Diablo’s frequency
response is also exceptional, extending
from just over d.c. (0.2Hz) to 350kHz
–3dB. With an even-tighter –1dB tolerance,
frequency response was measured as
extending from 0.6Hz to 120kHz. Such
wideband performance is unusual in such
a high-power amplifier. Within the audio
band, the frequency response remained
within 0.1dB of reference, as you can see on
the graph. Response at 20Hz was +0.05dB
then slowly ‘fell’ to be –0.15dB at 20kHz.
The top trace shows the amplifier’s
response into 8Ω, the bottom trace shows
its response into 4Ω, which is identical.
The trace running between the two is
the response into a simulated loudspeaker
load, which in dB terms, turns out to be
the ‘flattest’ response, coming in at 20Hz
to 20kHz ±0.075dB. This is particularly
good performance and means the Gryphon
will ‘sound’ the same no matter what
loudspeakers it’s driving. The amplifier
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Australian Hi-Fi
will also be able to easily control even the
largest-diameter bass drivers, thanks to a
damping factor of 380 at 1kHz. Channel
separation was also very good, as you can
see on the graph, hovering around 75dB at
all frequencies below 3kHz and diminishing
only quite slowly above 3kHz to be 63dB at
20kHz and 60dB at 30kHz.
The distortion graphs show higher
distortion that I’d normally expect in a
solid-state design, but it’s indicative of
the fact that Gryphon is not correcting
for distortion by using global feedback.
(Gryphon claims the Diablo is a ‘zero
feedback’ design.) As such, the spectrum
showing output into 8Ω at the 1-watt level
shows a second harmonic at –80dB (0.01%)
and a third harmonic at –84dB (0.006%).
TEST RESULTS
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28 |
TEST RESULTS
Gryphon Diablo Integrated Amplifier
There’s no mains hum visible, and the
general noise floor sits at –120dB above
1kHz (it’s above 100dB below 1kHz), so the
overall THD+N figure is 0.007%. Distortion
increases into 4Ω loads, with both the
second and third harmonics rising in level
to around –75dB (0.01%) and fourth and
fifth harmonics rising above the noise floor.
The fourth and fifth harmonic distortion
components are still more than 90dB down
(0.003%). Distortion increases considerably
at rated output, with significant
components stretching out to the ninth.
Further components are visible beyond this,
but all are more than 90dB down.
Testing for intermodulation distortion
using a 19/20kHz twin-tone revealed
sidebands at 18kHz and 21kHz that were
85dB (0.005%) down, and a regenerated
(difference) signal at 1kHz that was 80dB
(0.01%) down. Interestingly, this 1kHz
regeneration is something one normally
sees in valve amplifiers, and never in
amplifiers that use monolithic IC output
devices (the Diablo uses eight discrete
transistors in its output stage).
The square wave performance of the
Diablo is nigh-on perfect, particularly at
100Hz, where there’s no phase shift visible,
and the 1kHz signal is perfect, looking
every bit like it went straight from the
signal generator to the ‘scope! The 10kHz
square wave shows incredibly fast rise
time, and just a slight ‘kink’ that reveals
the upper limit of the amplifier’s frequency
response.
Signal-to-noise ratios were excellent
without being exceptional, measuring
88dB (A-weighted) referenced to one-watt
out and 103dB (A-weighted) referenced
to rated output. The 103dB result would
normally be superior, but in this particular
case, because the Diablo is so powerful,
it effectively shifts the goal posts by a fair
margin. If the amplifier were rated at just
100-watts, for example, the S/N would
have been 99.1dB. This is the reason it’s
best to reference signal-to-noise ratios
to 1-watt and use this figure as the basis
for comparison with other amplifiers, if
necessary.
Input sensitivity was quite high, with
just 37.5mV required to drive the output to
100kHz Square Wave (8Ω resistive load)
1kHz Square Wave (8Ω resistive load)
Australian Hi-Fi
one watt and just 605mV required for rated
output.
Steve Holding
Gryphon Diablo Integrated Amplifier - Power Output (Serial # 1112021)
Channel
Load (Ω)
20Hz
20Hz
1kHz
1kHz
20kHz
20kHz
(watts)
(dBW)
(watts)
(dBW)
(watts)
(dBW)
1
8Ω
282
24.5
290
24.6
280
24.4
2
8Ω
280
24.4
289
24.6
276
24.4
1
4Ω
540
27.3
539
27.3
510
27.0
2
4Ω
513
27.1
603
27.0
480
26.8
1
2Ω
882
29.4
900
29.5
880
29.4
2
2Ω
803
29.0
816
29.1
800*
29.0
Note: Figures in the dBW column represent the output level, in decibels, referred to one watt output. *Mains fuse
Gryphon Diablo Integrated Amplifier
Test
Measured Result
Units/Comment
Frequency Response @ 1 watt
0.6Hz–120kHz
–1dB
Frequency Response @ 1 watt
0.2Hz–350kHz
–3dB
Channel Separation
75dB/75dB/63dB
(20Hz/1kHz/20kHz)
Channel Balance
0.056dB
@ 1kHz
Interchannel Phase
0.02/0.08/1.54
deg (20Hz/1k/20k)
THD+N
0.007% / 0.787%
1 watt/rated o/p
S/N Ratio (unweighted/weighted)
82dB/88dB
dB re 1 watt output
S/N Ratio (unweighted/weighted)
97dB/103dB
dB re rated output
Input Sensitivity (CD input)
37.5mV/605mV
(1 watt/rated o/p)
Output Impedance
0.021Ω
@ 1kHz
Damping Factor
380
@ 1kHz
Power Consumption
3.79/43 watts
Standby/On
Power Consumption
207/NT
1-watt/Rated op 2ch
Mains Voltage Variation during tests
239–244 volts
Min–Max
10kHz Square Wave (8Ω resistive load)