AKV Acoustics Concepts
Appreciation of audio and musical reproduction is a subjective experience. We should therefore not let numbers or specifications on paper define what audio is/should be. Music, like art, is about emotional connection - measurements can provide a level of insight, but cannot be used as an alternative to human judgement.
Our products are all designed to the following fundamental concepts:
High bias, low power, single ended, pure class A
Fully balanced circuit designs
Point to point wiring
Use of fully regulated switching power supplies
1. High bias, low power, single ended, pure class A
Simplicity and a minimum number of components is a key element in designing what we consider a "pure" amplifier. The less components there are in the signal path, the purer the sound will be. This can be easily understood by the virtue of the fact that every component introduces some level of distortion, colouration, manipulation etc. - therefore for the sake of purity, musicality and transparency, less is more. This is true even if one more gain stage is added to improve the specification on paper. The simplest and purest form of amplification is known as class A.
For any amplifier, maximum linearity is desired. High bias (or idle current) ensures that maximum linearity is achieved. High bias is also crucial for creation of the sense of depth and ambience. This can be demonstrated easily: if the bias is reduced the perception of stage depth and ambiance will decrease. This perception of depth is directly impacted by the quantity of bias current. For this reason, all our amplifiers are highly biased in pure class A. They will run warm - the heatsinks on our power amplifiers will get to around 55-60 degrees centigrade - you can safely put your hands on it for 5 seconds or so.
In addition to being pure class A, all our amplifiers have a single ended topology - this is the simplest form of class A amplification with the least number of output devices, ensuring musicality and transparency. Our amplifiers are, in essence, the solid state equivalents of a SET (Single Ended Triode) valve amplifier, and sound like such due to the raw purity and musicality they deliver - but with none of the drawbacks and maintenance overheads that come with valve amplifiers.
Consequently (due to having single output devices), our amplifiers are "low power" output (for example, our Model P1 power amplifier provides 4.5 watts per channel). One should not, however, take this "low power" figure to mean a lack of power. This, paired with suitable loudspeakers, will allow for ear piercing volume levels. For instance, if speakers with sensitivity of 96dB/1m are used, 96dB of sound will be produced at 1 metre with only 1 watt of power (therefore 4.5w will be more than ample to rock out to!). To put these figures into context, the chart below provides some common decibel levels. As can be seen, anything above 100dB is reaching concert levels of sounds output - something which will never be needed or desired in the home.
We have had superb success driving many loudspeakers, including the Focal Aria 906, JBL L100 Classics, Klipsch R15M, Klipsch RP600M, Klipsch Forte iii, Monitor Audio Bronze 2 and the KEF LS50 - the KEFs are only 85dB/1m sensitivity, and our amplifiers drive these with finesse and authority! We encourage you to take a listen to our amplifiers - in most cases the power will be more than you will ever use.
The low output power means that AKV Acoustics amplifiers have their output devices working "fully" in their linear operating region. This, coupled with the high bias conditions ensures the output devices are always performing to the best of their ability - resulting in wonderful musicality and transparency. This is often where high powered amplifiers struggle - you simply cannot run the output devices in their ideal state as the volume will be too loud to cope with, both for your ears and your speakers.
Another common concern is the inability for a low powered amplifier to provide enough bass - this certainly is not the case with any AKV Acoustics amplifier; the nature of a high bias conditions ensures there is enough current delivery on tap to deliver deep and controlled low end frequencies. Take a listen to our amplifiers, and we are sure any misconceptions about bass delivery will vanish!
An additional benefit of being low powered means we can use fully regulated power supplies (as opposed to unregulated power supplies which are used in most power amplifiers). The details of this are described below under the Use of fully regulated switching power supplies section.
2. Fully balanced circuit designs
All AKV Acoustics amplifiers are designed to be fully balanced/differential (as opposed single ended/non-differential) from input to output. There are a number of benefits that a fully balanced design offers:
More power than the equivalent single ended outputs (typically balanced designs will offer twice the power output over their single ended counterparts).
They naturally cancel out noise and interference (known as Common Mode Rejection) due to their differential amplification design. In addition, this means that long interconnect leads can be used from your preamp/DAC to the amplifier without introducing noise and interference.
Stereo separation is generally perceived to be better in a fully balanced design, thus increasing the sense of space and musicality of the music.
Balanced connections are made via XLR connectors - these are stronger and sturdier than the RCA connections that are used for single ended designs, and therefore have a better longevity.
You may use any AKV Acoustics amplifier in single ended mode by using a XLR to RCA convertor - however we highly recommend you use balanced connections. A wonderful DAC with a preamp and remote control we recommend and sell is the RME ADI-2 DAC.
3. Point to point wiring
In most modern electronics, PCBs (Printed Circuit Boards) are used which contain thin copper tracks to carry the signal. This is counter intuitive to "high end" design, especially when you use decent quality interconnects and then have the signal go right from the inputs and outputs into circuit boards with thin copper traces. The only justification is a business one - PCBs allow for quicker production line manufacturing by machines, and thus significantly lowering costs.
Secondly, PCBs tracks deteriorate over time due to heat and wear and tear. This results in the thin copper tacks cracking. Point to point wiring ensures longevity of the product as it eliminates the issue of any potential copper tracks cracking.
All AKV Acoustics use point to point wiring and form any "tracks" with thick pure copper clad wire, with connections directly to the components using high quality solder. This is labour intensive, but it ensures the purest signal transfer and longevity.
4. Use of fully regulated switching power supplies
There is a common misconception that switching power supplies are "noisy". This is in fact untrue - a well designed switching supply supply can be much quieter than a linear supply. Linear power supplies cause hum and is due to the fact that they have large transformers and other components that operate at 50 Hz to 60 Hz (the standard frequency of mains AC). This is fully within our hearing range, and is extremely difficult to eliminate. The noise from switching supplies occur at frequencies well above the range of human hearing. If interference occurs, it will not have any impact on the audio signal and its amplification.
Note that AKV Acoustics amplifiers are not switching amplifiers - they are fully class class A. Only their power supplies are switching. The power supplies provide constant regulated DC voltages for the amplifier.
Most power amplifiers have unregulated linear power supplies - regulation is omitted in order to save power and reduce heat. This causes the power rails sag with every musical peak (even if large banks of "smoothing" capacitors are used). AKV Acoustics amplifiers, in contrast, have tightly regulated supplies and this means that the power rails do not sag when the amplifier is delivering peaks of power.
In addition to the above, all our power supplies are external to the amplifier, thus further reducing any noise interference that may occur with components. These are all industrial grade power supplies designed for constant use with large current capabilities - thus providing the rock solid stability, and therefore ensuring musicality.