The Hellion
HAM2.800D is a standalone 2-channel amplifier that can be used in any system,
although it was originally designed to complement the Hellion processor
amplifiers.
FIRST
INTRODUCTION, DESIGN FEATURES
Let's talk
about the dimensions. Length - less than 22 cm, width - 8.5 cm, height - only
3.5 cm. Comparison for clarity:
Nevertheless,
the power demand is not bad - 170W per channel into 4 ohms, 340W into 2 ohms,
and 680W is promised in the bridge into 4 ohms. In general, it can hold a 1 ohm
load (or 2 ohms in a bridge), but have the conscience to load the kid so much.
In short, 4 Ga power cables look reasonable.
But the
output terminal block is a bit modest - you can't connect thick cables.
Although the idea of a pluggable connection is very reasonable (especially if
the amplifier is to be placed in a hard-to-reach place):
Nothing
superfluous in the input section: gain, VHF and LPF. The filters are not
switchable. But they are adjustable up to 20 kHz. So there are no limits to the
amplifier's applicability - at least for subwoofers, at least for tweeters
(just in case).
And yes,
even high level inputs. With such a small size, there is a great temptation to
use the amplifier for "hidden" upgrades of standard systems. So they
come in handy. Tails with connectors are included, of course.
Plus a
wired level control. This is already a hint for subwoofer applications.
Opening the
case. As expected, the lion's share of the internal space is taken up by the
power supply.
The fuses
are inside. A total of 60 Amps for 2 channels of D-class is a clear indication
of the power capabilities (remember that the efficiency here is much higher
than that of AB-class, even if it is driven in B-class, as it is accepted
nowadays).
The power
buttons of the power supply and the amplifier section are lined up in a row.
However, the case is small and heats up evenly enough, so it's okay.
The drivers
of the amplifier section are placed on vertical sub-boards.
If you look
closely, you can see the good old IRS2092S. They are original from Infineon, no
analogs. This is a rarity in the budget segment these days.
In the
input section - without fanaticism, but also without cheapening - TL072 control
units are normal "workhorses". Scoring.
MEASURING
PARAMETERS AND CHARACTERISTICS
I'll start
with something simple - filters. Despite the wide range of settings (and even
in one pass), the characteristics do not float - the slope and goodness are the
same at every setting. This is very rare. However, it was not possible to cheat
physics with the linearity - the second half of the control range is very
sensitive anyway:
Now to the
amplification part. The output signal spectra are atypical for the D-class. At
low signal levels, harmonics are almost absent. As the level of the useful
signal increases, harmonics begin to appear, but with increasing order their
level decreases rapidly. It looks more like a good AV class.
I also
noticed the absence of background "dirt" in the signal, which is
often present in D-class. Any "side effects" from the impulse part
work almost always get into the audio range, and although their level is
usually low, you can still see them on the spectra. And here - nothing at all.
Okay. Background noise is somewhere around -100 dBV.
I'm
boosting the signal, the amp is putting out 10 watts. 4 ohms. The distortion is
fairly evenly distributed across the spectrum.
Switching
to 2 ohms (same 10 watts), the distortion character remains the same, the
increase is insignificant.
Since the
D-class output filter is supplemented by a non-disconnectable low-pass filter
in the crossover section, the phase of the output signal at high frequencies
fluctuates more than usual. But since the amplifier is not designed for
tweeters, I don't see anything wrong with that. The phase loss on the woofer is
just a consequence of the FM being on all the time. Everything is natural.
What about
distortion at different power levels? Again, there are no surprises - the
distortion varies within hundredths of a percent over the entire output power
range, except at 2 ohms where it goes up to a tenth.
Keep an eye
on the power levels at which the signal begins to degrade - the power reserve
for such a baby is surprisingly solid. If you don't want to look at the graph,
here are the numbers:
Hellion
HAM2.800D performance parameters (measured at 1 kHz):
4 ohm
operation, nominal output power (THD=1%) - 166 watts
4 ohm
operation, maximum output power (THD=10%) - 212W
4 Ohm
operation, THD (P=0.1Pmax) <0.07%.
2 Ohm
Operation, Rated Output Power (THD=1%) - 292W
2 ohm
operation, maximum output power (THD=10%) - 387W
2 ohm
operation, total harmonic distortion (P=0.1Pmax) <0.1%.
Just to
clarify - the amplifier can be connected to a bridge load, so at 4 ohms it will
produce about 600W without distortion (actually even more if we assume the
increase in THD to a few percent, which is quite tolerable for a sub).
That's
certainly enough for any subwoofer with 2" voice coils. And for most not
too tight subwoofers with 2.5" voice coils.
WHAT ABOUT
THE SOUND?
The amp
works perfectly across the entire bandwidth. And, pleasantly, without the
characteristic "dryness" that one would expect from a D-class
amplifier. Another reason to make sure that today's compact pulse amplifiers do
not allow us to treat them with neglect.
There is no
particular airiness in the top end, but I must admit that the informative part
of the HF range is well reproduced and the sound is not perceived as
"dark". However, this amplifier's main specialty is the bass and
midrange. In these areas, it shows itself as an energetic chipper, almost without
clamping the dynamics of the sound.
In the
bass, I expected a simpler control from such a small amp (by the way, the
control does not always depend directly on the power of the amp). But if we
take the same double bass from the CM Cup 2023 tracks, then, unlike many
amplifiers, the Hellion turned out to be able to keep the acoustics from
humming even at a decent volume. In short: Unexpected scoring.
IN SHORT,
TO THE POINT. FOR WHICH TASKS TO CHOOSE?
Definitely
worth considering if you need a compact (or even ultra-compact) amplifier with
full power reserve. It will work well in a woofer/midrange link or as a bridge
with most "civilian" subwoofers - these applications can be
considered the main ones for the Hellion.
However, it
works well (even excellent for its price) in the full band. For a MF link in an
SQ system its power may be excessive (although why not), but for pop MF arrays
(and when necessary - and for HF arrays too) it will be just right.
I would
like to point out that the amplifier can indeed work with a low impedance load
(1 ohm per channel or 2 ohms in the bridge), but here the psychological factor
comes into play - personally I am afraid to load such a baby with such a
complex load. Nevertheless, the manufacturer declares this possibility
(promising 2x760W and 1350W respectively), so you can keep it in mind.