Audiofrog - Because Experience, Quality and Truth Matters
American born Audiofrog is committed to designing and building the best products possible. Highly passionate about its business; great sound is what motivates this astute manufacturer to design and develop great products. However passion alone isn’t enough. The proof is in the products as they say, and the Audiofrog team have spent years making award-winning products. It's a company renown for cutting through the audio fog to provide straightforward products and information, free of all the mysterious and unscientific technobabble. Audiofrog products might not be cheap, but value isn’t determined by price alone. For when you compare the attention to detail, the features included and the performance of Audiofrog products to other; you’ll agree that exceptional is worth a little extra.

Amplifier Series – Passion Measured In Watts.
As someone both proud of their beautiful vehicle and obsessed with aural perfection, when it comes to powering your sound system would you not commit to the same level of passion? Of course you would, and Audiofrog has just the range of amplifiers to handle that very task. With their ultra-technical topology, sleek lines, astoundingly accurate sound and enormous power output; Audiofrog amplifiers have the gumption to keep up with every other aspect of your pride and joy.

Design Ideologies
Sometimes great products are the result of a new invention; a technological advancement that unlocks performance, features or applications never before possible. We have people like Henry Ford and the Wright Brothers to thank for those kinds of advancements. Great products therefore, are often the result of painstaking attention to detail and optimisation of existing technology. Put succinctly; someone got a whole bunch of stuff right and the results are amazing.

Class D Amplification Done Right
Class D amplifiers haven’t always been great. Early versions, which debuted nearly 30 years ago; were fraught with problems. Noise, instability and distortion were three significant shortcomings. The promise of class D smaller chassis and higher efficiency were always at the forefront but audio performance never quite approached that of class A or even class AB. As with most things technical this methodology has evolved out of Nowadays there are class D amplifiers that rival the best performers in any class.

It’s All In The Details
Thanks to a host of features together with Audiofrog’s painstaking attention to detail and optimization; these class D amplifiers provide the high power, low noise and low distortion performance audio enthusiasts expect in small and rugged chassis that are easy to install and can be made to fit nearly anywhere.

Design Features
The rich heritage of this astute and masterful designer, together with its ever-increasing technical acumen; is conducive to these components featuring a vast array of impressive design ideologies incorporating the latest technological advancements. Some of these include:

Advanced Circuitry
Board layout is a key component of a high fidelity amplifier design, especially when miniaturization is a key feature. Audiofrog amplifiers incorporate a four layer PC board that helps to isolate the magnetic circuit in the power supply and class D modulators from the amplifier’ preamp and audio sections. Small I/E transformers oriented to place the preamp circuit in a magnetic null replace the toroidal transformers often used in larger designs. High speed switches responsible for power supply and output voltage are located on the opposite side of the board from the preamp and audio circuits and are isolated by an internal shield layer. Heat is transferred from the switches on the bottom of the board to the heat sink on the top through heat sink pads incorporated into the top and bottom PC board layers.

Ultra-High Frequency Switching
Ultra-high frequency switching in Audiofrog’s designs move the power supply switching frequency to 100 kHz and the class D modulator frequency to 420 kHz. This allows for dramatically smaller magnetics and smaller transformers make a smaller amplifier possible. In addition, the higher modulation frequency makes it possible to move the output low pass filter frequency an octave higher than many other class-D designs. The output filter in Audiofrog’s designs is set to 40 kHz rather than the usual 20 kHz.

Because the output filter in a class D amplifier is a passive low pass filter, it has to be designed for a specific load; usually 4 Ohms. When measured with other loads the frequency response changes at and around the filter frequency. A higher resistance load creates a peak at the filter frequency and a lower resistance load causes attenuation at and around the filter frequency. This has long been a criticism of class D design. For an amplifier designed primarily to drive speakers at low frequencies and which includes a built in low pass filter in the on-board crossover, this output filter doesn’t have any real effect on the usable high frequency response of the amplifier. This allows the amplifier to provide plenty of power in a small chassis perfect for driving high-end subwoofers.

Integrated Feedback
Based on IR’s 2092 integrated class D audio driver, feedback through an operational trans-conductance amplifier provides an analog version of a sigma-delta convertor, which shifts error in the audible frequency range upwards to the inaudible high-frequency spectrum thus dramatically reducing noise in the signal. Dead time is programmable for optimization of zero-crossing with minimum distortion. Audiofrog’s class D amplifiers provide noise and distortion performance that rivals the best class AB amplifiers in significantly smaller and more efficient packages.

Heat Sink Shield
Audiofrog’s amplifiers include a dual purpose heat sink that also acts as an EMI shield. The heat sink and the bottom plate are electrically connected to each other and to one of the internal PCB layers through a trace that runs the perimeter of the board on the top and on the bottom. Combining the sink, the bottom panel and a PCB layer help to minimize electromagnetic interference emitted from the amplifier, which prevents degradation of the radio’s FM reception. Compared to many other class D amplifiers Audiofrog’s amplifiers emit less noise, which preserves FM reception and minimizes radiated noise which may be picked up by other audio components.

Differential Inputs
As the name implies, differential signal inputs are designed to amplify the difference between the positive and negative signal conductors. Differential inputs are suitable for use with both balanced outputs, in which one conductor carries the signal and the other conductor carries the inverse of the signal, or with single-ended outputs, in which one conductor carries the signal and the other conductor is connected to audio ground.

In cars, audio ground is often the same as power supply ground; which is chassis ground. Chassis ground is also ground for every switch and motor in the car and also for the alternator. Many previous amplifier input topologies used single-ended inputs, which were notorious for creating ground loops; for susceptibility to radiated noise and for susceptibility to noise on the power or ground circuits. It doesn’t matter how quiet the amplifier circuit is if the input is noisy. With single-ended inputs, shielded cable should be used. The shield is designed to prevent noise from making its way to the signal conductor in the center.

Differential inputs solve these problems in two ways. First, neither conductor is connected directly to chassis ground, so the potential for ground loops is nearly eliminated. Second, because signals that appear identically on both conductors are cancelled through CMNR (common mode noise rejection), radiated noise, picked up by the cables, can be eliminated in the input preamp. In order for this to work, it’s important to use twisted pair cable rather than shielded coaxial cable. Twisted pair cable is designed to expose both conductors equally to radiated noise so it can be cancelled in the preamp.

Because the connection to ground is eliminated in the input section, differential inputs are suitable for connection to both the single ended line level output of head units and signal processors and for connection to the balanced, speaker level output of head units and factory installed amplifiers. RCA jacks are provided for standard preamp connections and a convenient Molex style connection plug is provided for connection to speaker level outputs.

Audiofrog’s amplifiers include differential inputs suitable for connection to single-ended or balanced line level sources up to 10V or speaker level sources of any kind up to 30 V. Speaker level and line level inputs also include signal sensing turn on for applications in which no remote turn on lead is supplied by the vehicle’s head unit.

Flex Crossover
The A600.1D mono amplifier is designed to drive subwoofers and includes a high pass filter with a frequency range from 5 Hz to 40 Hz suitable for use as a subsonic filter for vented enclosures or for use with small subwoofers. The low pass filter is adjustable between 50 Hz and 500 Hz making it appropriate for subwoofers or for midbass drivers. When used with an outboard processor or DSP the filters can be selected at 5 Hz and 500 Hz to keep the onboard crossovers well outside the subwoofers bandwidth. In addition the A600.1D includes a phase adjustment control to make getting the phase right between the subwoofer and the midbass drivers easier, even in systems without a DSP. These crossovers can be defeated when the amplifiers will be used with a digital signal processor.

Electrical Specifications
– Nominal configuration: one channel class D amplifier
– Continuous power @ 4 Ohms: 1 x 450 Watts
– Continuous power @ 2 Ohms: 1 x 600 Watts
– Frequency response: 10 Hz – 400 Hz
– Total harmonic distortion: 0.02 %
– Damping factor: 600
– Signal-to-noise ratio: 108 dB

Physical Specifications
– Length: 210 mm
– Width: 126 mm
– Height: 32 mm
– Weight: 2.4 kg

Documentation
– User manual

Important Disclaimers
Given the dynamic nature of electronics industries these days; below are listed some very important specifics you need to be aware of.

Brand Authorization And Stock Sourcing
We are a fully authorised Australian dealer of this brand and all stock is sourced through legitimate channels. It therefore enjoys full Australian warranty, backing and support.

Pricing Structure
Whilst we endeavor to offer the best price possible, we ask that if you do find a better price elsewhere from an authorised dealer; please contact us. Also be aware that we regularly conduct group buys and sales, therefore pricing can sometimes be subject to change without notice.

Stock Structure
Being a dynamic store is conducive to our inventory constantly changing. We list only a small portion of our stable online, usually products most popular. Aside from these we also stock numerous other variants and configurations of these products, hence if you don’t see what you’re after please contact us.

Shipping
All our products are shipped with registered and insured postage. Upon ordering you’ll be issued with a receipt, a consignment note via which you can track your order, and we’ll also SMS you photos of the package for identification purposes.

Technical support
This last one we cannot emphasise enough! Please contact us if you require any further information or assistance with the setup and use of this product, especially pertaining to aspects more technical. As we want you to get the very best from this product.