The Hellion
HAM4.8pinDSP Compact Processor Amplifier is under review. It offers 8 channels
of processor and 6 channels of D-class amplification.
At first
glance it seems to overlap with the HAM6.80DSP (both earlier and later
versions). But no, the number of channels is the only thing they have in
common, this unit is built differently and aimed at a different application.
This will become clear as we go on.
FIRST ACQUAINTANCE, MAIN FEATURE OF THE
CONNECTION
One of the
features of this amplifier is the connection. The principle itself is generally
not new - the amplifier plugs into the head unit connector, receives a high
level signal from the head unit, and outputs an amplified signal to the
standard speakers. Plus, there are two more channels of amplification that can
be used at your discretion (for example, to connect tweeters so that the front
is channel-by-channel). Well, plus two more channels as line outputs (these are
logical for the sub-link).
And in the
simplest case, Hellion gets power from the standard wiring (at least until we
decide to "overclock" it in full force by connecting power
separately, which I will talk about later).
Only usually
manufacturers provide connection in the break of ISO connector or simply put
"tails" of wires in the kit. And here - exactly the same chip as in
most Android head units (they are, as a rule, unified). And no unnecessary
adapters.
I.e. we
take the connector out of the head unit and put it into Hellion. And in turn,
we connect it to the head unit with the harness from the kit. The amplifier
itself receives power from the standard wiring and transmits it "in
transit" to the head unit. The same chip sends the audio signal from the
processor to the speakers. And often it also receives signals from standard
steering wheel buttons - there is also a "transit" through Hellion
for them.
And if you
have a head unit with a different connection chip? No problem, you can cut the
wire from the kit and there you are - and input and output "tails"
that can be connected wherever and however you want.
For cars without ACC wire, as usual, there is an automatic switch on when a signal appears on the high level inputs (or rather, when a constant component appears on them).
A FEATURE OF AMPLIFIER OPERATION. LIMITED OR
FULL POWER?
Now for the
"dual" power supply. The first mode is when we plug the amp into the
head unit jack and it gets power from the standard wiring. It is dangerous to
overload it, so the amplifier works "bypassing" the boosting power
supply, directly from the vehicle's electrical system. Obviously, the output
power remains approximately the same as that of the main sound system itself
(only the amplification channels are 6 instead of 4).
Nevertheless,
there is no need to draw an analogy with models that use "magnet"
chips. In any case, we get better amplification due to the more advanced
D-class. In addition, Hellion uses very good TPA3116 power chips.
In general,
these chips can work with higher voltages, which allowed us to realize the
second mode of operation - when the power supply is connected through a
separate connector. The device "realizes" that it is no longer
necessary to limit itself in the power supply, and the amplifying part starts
to work through a boosting power supply. The output power increases
accordingly. The additional power is supplied by a separate block, combined
with the outputs of channels 5/6.
WHAT ABOUT CONNECTIONS?
If at some
point you feel that your own amp is not enough and you want to use separate,
more powerful ones, the channels of the built-in processor (let me remind you
that it is 8-channel) are output as line outputs (except for channels 1/2 -
this pair goes only to your own amp). So there is a possibility to make another
step in the system development. It is up to you to decide on which of them to
stop (simple integration into the gap of the radio's socket, with an additional
power supply, or further development of the system by adding separate
amplifiers bypassing the built-in ones).
According
to the sources, the picture is as follows. The 4-channel high-level input
mentioned above - that's one. Separate line input (AUX) - that's two. An
optical digital input is three. Built-in Bluetooth module - that's four (works
to receive audio streams, and also allows you to customize the processor via a
smartphone app).
And the
fifth is USB audio, i.e. Hellion can work as an external sound card (probably
for the same "android" control panel, it all depends on the model) -
for this you need a cable with USB-A connectors on both ends.
For
smartphones you can buy an additional set of two cables, I just mentioned it in
the previous review of one of the Hellion devices - it's an extension cable
plus an OTG cable with an additional power connector.
There's a sixth source, though, and that's a USB player. If you plug a flash drive with audio files into the same USB audio port, it will start playing. For now, this can be considered a future plan, as you can only control playback from a smartphone application, and it was still in the works at the time of testing (although the first variants were already in my hands).
The
amplifier is built on three bridged 2-channel TPA3116. In the linear part we
can see 4580 operational devices with JRC manufacturer marking. Signal
processing is based on the CS4953 DSP chip from Cirrus Logic (by the way,
another device from Hellion - DHL-6 high-level signal processor converter,
which I disassembled at the end of last year).
HOW TO
CUSTOMIZE
At the time
of this review, only the PC program (connected via USB as usual) is available
on the official website. But there are plans to release two Android apps soon:
one for smartphones and Bluetooth connection, the other for GU and USB
connection (or also via Bluetooth). In principle, this is logical, since the
device is literally aimed at working with "Android" devices.
By the time
you read this, the applications will probably be available, and if not, I'll
refer you to the review of the aforementioned Hellion DHL-6, built on the same
platform - there I just gave screenshots of working versions of the applications.
As far as
customization is concerned, the processor part here is full-fledged, with
absolutely equal channels that can be configured individually (not just in
pairs, as in most DHDs). Frequency filters, delays, equalization - there are no
special restrictions. Up to 10 custom configurations (presets) can be stored in
the processor's memory.
And yes,
note the 4/2 ohm toggle button at the top of the screen. At first glance it
might look like it has something to do with the power supply, but no, it works
a little differently.
The thing
is that Hellion has a rather sensitive protection system - it switches off the
amplifier when the output reaches a critical level of distortion (a kind of
"foolproof"). But as practice has shown, the best is the enemy of the
good, and sometimes it starts to work when connecting 2 ohm speakers, when the
user wants to "pump up the volumetrics".
In fact, in
"2 Ohm" mode, this switch only introduces a slight compression of the
signal (soft amplitude limitation), thus pushing back the threshold of the protection
operation. This switch does not affect the power supply mode of the amplifier.
MEASUREMENT PARAMETERS AND CHARACTERISTICS
First of
all, I simulate the simplest type of connection - into the connector break of
the radio. In this case, the amplifier receives power from the standard wiring
and operates in reduced power mode.
In general, it does this quite cleanly - the background noise is moderate, the harmonic spectrum is not particularly scrappy. Again, the level difference between the second harmonic and the main signal is more than 70 dB, which means the gain is about 0.01-0.02%, not more.
Connect the
power supply to the auxiliary input. The amplifier begins to operate in normal
power mode. Background noise is slightly increased, but remains within
reasonable limits. The character of the harmonic distortion and its level are
preserved. A slight ripple of unnecessary artifacts - this is the power supply
that has already been switched on, but the level of these artifacts is stable
below -90 dBV, so there is no crime.
Now about
the difference in power reserve - does it make sense to connect the power
supply through a separate connector or can we make do with the power supply
from the GU connector?
For
clarity, I conducted an experiment - I fed a signal from the measurement
complex to AUX and simultaneously watched what happens at the amplifier output.
Volume in the program - to the maximum of 40 units.
When the
power is supplied through the main connector (when Hellion is plugged into the
main unit's connector break), the amplifier part is supplied without voltage
increase, so the maximum output swing is expected to be the same as that of any
ordinary main unit.
However, if
the power supply is connected through an additional connector (and a boosting
power supply is used), the amplifier can already produce a signal amplitude
that is 1.5 times higher (about 3.5 dB in voltage). Not fanatical, but
significant.
By the way,
there is a little trick in the description of the amplifier. It states an
output power of 80 W per channel, but this value is obtained by taking into
account the amplitude value (about 18 volts). In other words, it refers more to
the power reserve of the power supply than to the undistorted power, which in
this case will formally be slightly less.
WHAT ABOUT
THE SOUND? TEST IN CASE
General
character of the sound. Once again, I'd like to point out a rather successful
realization of the TPA3116 chips in Hellion amplifiers - the sound is bright
and dynamic, with good attack transmission. There's no warmth in it, but it's
not stiff or prickly, rather it's somehow open. It would be wrong to compare it
to the "magnetic" AV class: this is a completely different level, two
levels higher. Of course, it is also wrong to compare it to audiophile
amplifiers, but when connected to a good source via optical or USB audio, we
can talk about very good detail. Considering the price, the result is very,
very decent.
Even taking
into account that in most cases the Hellion will be used on the high level
inputs, the difference is significant. The amplifier itself will work in a
different mode (on the almost resistive load of the Hellion's 13-ohm high level
input with lower output stage currents), so it will no longer be the bottleneck
of the system. The Hellion will do the work directly at the loudspeaker and has
a higher potential in this sense. As a result, you can expect a more "contrasty"
sound - I usually compare such a difference to a blanket falling off a speaker.
Does it
make sense to use an additional power supply? I can't say that the difference
is immediately noticeable, but after listening to the amp for a while in normal
power mode, when you switch back to low power, something is missing. So don't
be lazy, pull up a few wires (well, you don't need thick ones, you can do it
with 4 square millimeters) and connect them to an additional connector.
Choice of
acoustics. This is also an important moment to reveal the amplifier's
potential. To be honest, I would not choose heavy speakers, it is better to
focus on light moving systems and high sensitivity. Though, perhaps, not as
fanatically as when choosing for simple connection to the loudspeaker - the
choice is still wider. And, in general, if you plan to upgrade your system step
by step, you can leave the standard loudspeakers alone for the time being.
GETTING TO
THE POINT. WHAT SHOULD I CHOOSE FOR?
If you have
an "Android" head unit - this device is for you. In the simplest
case, you plug it into a pin-to-pin connector and you get a full-featured
processor with independent tuning of each channel (not paired like the built-in
processors in the head unit). Plus two additional channels of amplification,
better amplification in all 6 channels, even with the same output power. And
you can connect a sub amplifier or an active sub to the line outputs 7/8.
If this is
not enough, you can connect an additional power supply with a "flick of the
wrist" and get more output power. This does not so much increase the
volume reserve, but improves the dynamics of the sound at normal volume levels.
Still not enough? You can use the Hellion as a processor and connect any
separate amplifier to its line outputs.
And compare
it to the Hellion HAM6.80DSP mentioned at the very beginning (it doesn't matter
if it's an earlier or later version). It connects to standard head units like
any other processor amplifier, but it has one fundamental feature - it is able
to destroy several zones (we are not talking only about marine sound, but also
about dual car systems "everyday + pop"). But HAM4.8pinDSP is a bit
simpler in some aspects, and not very suitable for such systems, but it is
perfectly compatible with "android" HAMs. Furthermore, you want to
use a simple pin-to-pin and even without a separate power supply, and you want
to use it with increased power, or even as the "brain center" of a
more developed system. It also allows a step-by-step upgrade with minimal cost
at each step. So they have fundamentally different target audiences, despite
the same number of DSP and amplification channels.