True audiophiles are always looking for devices to improve the sound quality as much as possible. With class A amplifiers, you will achieve even more than that — a new outstanding experience of how your music can really fly in the air. Want to know more? Keep reading this article!
Table of Contents
- Editor’s Choice: Quick Comparison
- Reviews Section
- Theory Boost: What Is Class A Amplifier?
- Buyer’s Guide
- Wrap It Up
Editor’s Choice: Quick Comparison
1. AudioSource Analog Stereo Power A Amplifier
The best class A power amplifier is really a nifty device to show off: the frontrunner of our top 3 is the model by AudioSource. This is a sample of two-channel machines. It is capable of producing fifty watts RMS power at eight ohms. If the ohms rate is four, then each channel performs at sixty watts. If you bridge the item, then the power literally flies up to one hundred and sixty watts into a mono load.
Overall, the toolbar of the equipment is incredibly easy to navigate. That’s why the operation turns out to be a real breath for any user, regardless of the fact how well-experienced he is. On the front panel, a power switch turns green when there is a signal present. Speakers’ selectors for A and B are also located there. Besides, you can control the balance and volume levels with the help of convenient knobs.
On the back of the device, consumers can find unswitched convenience plug, five-way binding posts for speaker sets. In addition, a special auto-on mode which ensures the amp the best class A portable amplifier will turn on when there is a signal present automatically. A mono stereo switch bridges the device.
With the help of RCA jacks on the back panel, any consumer can connect the machine to several acoustic systems. By the way, this device is compatible with a multi-channel home theater.
All in all, the AudioSource equipment is a fantastic stereo amplifier for integrating into a home theater, distributed audio system, and for standalone enjoyment. For installers, it is a dream solution because it is intuitive in setup process so that any client can use it without a single problem. Just check it out!
2. Nobsound 6P1 Vacuum Tube Power Stereo Class A Single-Ended Audio Amplifier
Without an exaggeration, our runner-up on the list is extraordinary in many ways. Firstly, the price is really reasonable. If you compare the class A amp with other class alternatives, you will surely find some cheaper solutions. However, when considering the Hi-FI audio equipment sector, it will turn out that this model is extremely competitive.
If you are looking for a classic tube listening experience, then there is a good chance you will adore the equipment’s performance. If you are striving to get something that has dimension to the sound, layering within the soundstage and warm sounding within the mid-range, then this device is your soulmate. The matter is not the power, crunching, dynamics, or accuracy: this best class A amplifier will give you a colorful sound presentation.
When you listen to the machine’s performance, you will notice a slight V-curve: the treble can be boosted a little bit, as well as the bass will be more powerful in some moments. That means the sound produced will achieve several extra shades and notes to impress you with its brightness.
The manufacturer has equipped the machine with several top-notch features to avoid any possible issues. For instance, the model differentiates with low static noise. This effect is achieved due to the anti magnetic transformer covers. Moreover, the adopted transformer parallel output is a key to internal resistance reducing. That means you will achieve a great boost of the product’s power capabilities.
Of course, the item’s design is something unbelievable. It may not be as portable and compact as some class D amplifiers, but this model is definitely one-hundred percent more eye-catching. Its vacuum tubes and VU meters are not only functional elements but will suit as a décor for any place.
3. Reisong A10 EL34 Hi-FI Audio Stereo Tube Amplifier
In our top list of the best class A solutions, the bronze medal goes to the Reisong product. If you doubt which item to give your preference to, you are welcome to go for this product since it is manufactured by a leading brand in the industry. Reisong is famous for its professional approach to creating equipment. Moreover, they are known for their exclusive customer support. Feel free to contact them if you need a circuit diagram or want to determine some aspects of the device’s operation. They are easily reachable by email.
This purist two-channel audiophile solution features point-to-point which is usually available in equipment for over a thousand dollars. With this device, consumers are not going to get something so common as built-in DAC, a phono stage, a remote control. You will achieve two EL34 power tubes that will output twelve watts per channel. If you ever need to swat the element, you can easily do so and prolong the life cycle significantly.
The intuitive navigation is a great thing when it comes to something as unique as the best class A tube amplifier. For instance, a special black button is added for customer convenience. Its main function is promoting switching between AUX and CD output. Besides, it is a simple precaution measurement: consumers are to press it if there is no sound even after waiting for a while. Speaker terminals include ground, four-ohm, and eight-ohm taps. There you can also find IEC inlet.
However, there are two significant drawbacks of the item if you have limited space opportunities at your place. The product differentiates with pretty big dimensions and weight. Besides, the price tag makes it an expensive item which may be not affordable for some customer categories. On the top of that, a special construction requires some time of work to be able to produce maximum power. The manufacturer recommends consumers to operate the machine within first 30-100 hours to achieve the harmonious performance. Even though the sound may not be the best during the period, then you will see this purchase is worth waiting for. There is just something unique about the sound that you don’t really get from the majority of transistor amplifiers, especially super affordable ones.
Theory Boost: What Is Class A Amplifier?
By this notion, we mean a device that produces signals during the full cycle or has a conducting angle of three hundred and sixty degrees. Apart from this type, you can find class AB, D, C, and H amplifiers. The one under consideration is the simplest and most common among all of them. Class A is known for low signal distortion levels.
Such operation allows a full swing of output for the full swing of input so that voltage is going all the “line” through, never actually reaching saturation and cut off. That concerns BJT class A equipment.
Directly in the process of amplifying an audio signal, three structural elements are involved in the amp’s radio tube: anode, cathode, and grid. When power is supplied between the anode and cathode, an electron flow occurs. At the same time, the grid located between them acts as a control valve.
At first glance, the scheme is pretty nice. Firstly, it is simple, concise, and is an excellent example of a short sound channel. Secondly, a lamp or transistor in class A is constantly in working condition. That is why it instantly responds to changes in the incoming signal. Thirdly, the middle of the electronic component working range is the area in which the device operates as efficiently as possible and without distortion. This means that if you do not increase the amplitude to the limit values (you simply don’t turn the volume knob especially hard and don’t connect a heavy load device to the amplifier), the amp will work exclusively in a comfortable mode. Besides, the output signal received will have almost the perfect appearance.
Of course, it has its fair share of advantages and disadvantages and is not so wide spread currently, but it is pretty effective. You can hardly meet this circuitry in high power applications though.
Unfortunately, all these advantages without side effects can be realized only in low-current circuits of the pre-amplifier. When it comes to working at the capacities needed to interact with speakers or other large acoustic systems, class A shows its equally obvious disadvantages.
Apart from the already mentioned low signal distortion levels, the main characteristics of the class A device include the following:
- Simple design;
- Quite stable;
- Low efficiency due to being switched on all the time, around the vicinity of 25-50%. Let’s consider an example of 20%-efficiency. It means that for every five watts your amplifier consumes, only one watt basically comes out at the output, so four watts are simply wasted on the track;
- No standby mode, which in turn causes great energy consumption;
- Highest linearity;
- High heat output during operation. An increase in operating temperature can adversely affect the working mode of the reinforcing element. Therefore, a class A transistor amplifier that produce at least some significant power have huge radiators;
- The tool is always working due to amplifying element bias.
During operation, following the increased energy costs, an audiophile will sooner or later face another problem — the increased wear of the circuit’s active elements. There may be issues with lamps. Being applied in the device under consideration, they are constantly under pretty heavy load which reduces their work resource.
If we are talking about the amplifier’s modes of operation, the class A devices are truly pioneers in the field. They were the origin which helped develop other circuitry types. However, despite the fact that this kind of amps has already managed to celebrate its centenary, it is still in demand and competes on a pretty equal footing with the most advanced modern classes of the twenty-first century.
Despite all the shortcomings and technical features, class A amplifiers form a noticeable niche in the Hi-Fi technology market (in its High End segment), where the size, power consumption, operation complexity and even price are often neglected since the sound quality the type produces is really amazing. Besides, since 1916, when the class A was invented, a lot of improvements and modifications have been done to increase the efficiency and minimize the drawbacks. For instance, a lot of models possess a special eco mode regime which reduces the energy consumption up to 35%. In this perspective, even if you leave a device without guidance, it won’t waste too much resources and warm up the place where it is situated.
However, focusing only on the class of an amplifier would be a mistake since each machine has its own specifications to pay attention to. For connoisseurs of truly high-quality sound, it is recommended to consider the following parameters as well:
- The device’s power is one of the main things to bear in mind. It is necessary to check how much load the amplifier has to “resist” when working with your speakers or other sound equipment.
- Signal to noise ratio is to be taken into consideration if the device is going to be used for subwoofers or other-frequencies equipment. Overall, the higher this indicator is, the better the sound quality will be.
- Sizes. Taking into consideration the fact that class A amplifiers are considerably bigger than class D mini devices, you should think how much place you are able to afford for the machine’s location.
All in all, the class A amplifier shows its only positive aspects if there is no need to connect it to high-power acoustic systems.
- Does the class A amplifier produce a better sound that other types?
To tell the truth, its circuitry promotes clean and natural sound. However, it depends a lot on the model, its specifications, and additional features. Even if you compare two machines of the same class, one of them can represent the up-market industry sector, while another will be just a mid-fi. Without a doubt, class A amplifiers are great when it comes to music representing, but they are not necessarily the best.
- What are the main amplifier classes?
Overall, there are over ten different types of circuitries. Apart from the commonly known A, D, and AB, you can also find E and T amplifiers, etc. One of the main differences between them lies in the kind of topologies applied. For instance, pulse width modulation technique used in modern equipment is to drive and generally control the output load.
- How can I use class A amplifier?
In general, they are used for several acoustic systems like speakers. However, their efficiency for subwoofers depends on the available range of frequencies in a particular model.
- Which equipment of the kind has the highest distortion?
It depends on the manufacturer’s technologies and techniques applied. Experts consider the class A the frontrunner in this competition though. This type differentiates with its low distortion due to the special circuitry design.
- Are there any differences between class AB and class A amplifiers?
Class AB is a combination of two other types, including class A. In simple words, their main difference lies in the fact that the transistors are not biased at the same point. While distortion is inescapable in class AB, the opposite case shows that output information is reproduced in the same way as input signals.
Wrap It Up
To purchase or not to purchase — for quality sound true lovers, there is no question like that. In this perspective, class A amplifiers have numerous chances to prove that devices with long-term history are precious and really worth consideration. Enjoy the colorfulness in every note with class A amplifiers!