INFO / SONXPLUS - How much should you invest in a stereo amplifier?

To mark the return of the Montreal Audio Show in March, this article will follow up on our series on stereo systems where we studied the path of musical notes from the instrument to the listener's ear.

Now that we know what forms a sound wave, but also how to capture and codify it in order to read it, we will focus on the last step which consists in amplifying the signal to make it audible.

 There are different types of amplifiers available in a wide range of prices. It is very important to understand our needs and expectations in order not to be disappointed. As a preamble to a future article, we will make a link with the other pillar of sound reproduction: the speaker. Both elements have to be bought in consideration of each other.

Follow the guide!

 4 types of stereo amplifiers.

  The power amplifier.

This type of device is sought after by the serious audiophile who wants power and precision. This type of amplifier only feeds the speakers and requires a preamplifier to select the sources and adjust the volume. Generally speaking, this is not what beginners are looking for, it is worth it, but it is more expensive. Preamplifier

People who buy this type of device want to tailor their set to their taste, adapting their budgets to the sophistication of the device. For example, if you never listen to FM radio, you won't have to invest in a radio tuner, leaving you with more budget for the other components you care about.

 The integrated amplifier.

An integrated amplifier is a device that allows selection of the input source, adjustment of volume and tone. This is in contrast to a power amplifier, which will not allow selection or control and will require the mandatory addition of a preamplifier for this purpose.

 The receiver (Radio or Network)

Here, we are referring to an "all in one", because, in addition to amplifying sound to desired listening levels, it will allow listening to sources such as good old FM for radio receivers, or now, web radio in its Network version. In addition, the network receivers will incorporate a DAC or digital analogue decoder to listen to the famous FLAC and DSD files available for download on the market. In addition, there will usually be a digital coaxial or fibre optic input socket to allow connection of a CD or DVD player or a recent television set.

 The ultra compact network receiver.

The compact network player amplifier is a relative newcomer. This type of device involves a built-in amplifier to allow for the attachment of various peripherals, but also incorporates a full suite of functionality for the digital world of webcasting. Using new design possibilities, it will be very compact and user-friendly, incorporating a large display and an application similar to that found in network players (see our previous article). This type of product is set to grow in popularity. It is the ultimate in fidelity and performance.

 What you need to know before investing...

Without going into too much detail, one should look for a low distortion rate below 0.05% in order to ensure good realism when listening. The second point will be the power, which should be at least 50 watts per left and right channel for ambient listening, i.e. 100 watts in total. 200 watts and more will be required for a more dynamic listening.

Note that the more power you have, the more distortion you can avoid in your listening, as the amplifier will not "force". It is well known that the sound quality degrades rapidly when you exceed the capacity. Furthermore, an "Amplifier" that is not powerful enough for your needs can damage your speakers...

Many people believe that speakers need to be more powerful to be able to withstand abuse, but this is a mistake, as the opposite is true. An amp that is too powerful will provide a cleaner current that will cause the speakers to snap when pushed a little too hard, so you will hear it and turn down the volume. Conversely, an amplifier that is not powerful enough by exceeding its capacity will provide a continuous current that will melt the speaker coils. You won't hear the extent of the damage, because DC current doesn't generate any sound... except when it's too late...

Lastly, the signal-to-noise ratio should be less than (- ) 100 decibels or more, so that the reproduction is not affected by noise that steals power and dynamism!

 Q: HOW MUCH TO INVEST > AMPLIFIER? 

A: It will depend on your requirements at the time and on your personal path among the following 4 categories:

Beginner : For those who want to experience the richer listening experience of specialized sound equipment. An experience far beyond car or portable radios of any kind.

Serious: For anyone who wants a more truthful listening experience with a better ability to handle the more power-demanding passages that cause distortion, but without investing too much.

Purists: similar to the serious investor, but one who does not compromise in the ability to reproduce soft passages (without background noise) to the most thunderous passages such as Pachelbel's canons or sustained passages as found in heavy rock or techno beats.

Audiophiles: Those who make it a real passion, for them it is the search for perfection...

• Beginners: $350 to $699

Yamaha AS-301B

• Serious: $700 to $1499

Cambridge Audio CX-A61

• Purists: $1500 to $2500

Denon PMA1600

• Audiophiles + $2500

Naim Uniti Nova

The speakers

There are two main categories to start with, full size tower or floorstanding and book shelf. For now, small speakers remain a compromise, which once pushed to the extreme (the very small ones) will destroy the fidelity that the quality amplifier will produce.

... In fact, to try to hear the low frequencies, the bass setting will be raised, which will make the speaker work too hard, which in turn will degrade the overall sound. You will then have the choice of either a lifeless setting, but with a crystal clear sound or bass, but with obvious distortion.

Adding a subwoofer will not solve anything, as it will be difficult to calibrate so as not to cover the sound of the small speaker. It will be desirable to choose a medium format speaker or ideally a full format (tower).

As a general rule, a diaphragm larger than 5 inches (12.5 cm) should be sought for the bass. One in the shelf format and two or more in the full format. A two-way speaker (speaker diaphragms) forming a bass and a treble will do the trick, while the larger "columns" will offer 3 ways, which is better for the fidelity of the sound produced.

It is interesting to note that our full-size speakers are no longer as massive as they were in our parents' day.

In the past, there were loudspeakers up to 15 and even 18 inches (37 to 45 cm) in size to produce a deep and powerful sound. Such behemoths were not very elegant. New technologies now allow similar performance using a diaphragm of only 8 inches (20 cm) or less. The result is slimmer, less intrusive speakers. So much for modernism!

 Speakers, make a careful selection.

Here, however, it's more complicated to choose than with amplifiers, as the speaker industry has an unfortunate tendency to hyperbole, exaggerating their achievements. More than ever, buying speakers requires good honest advice and a listening session to validate it. Recommendations from friends can be helpful, but the final decision will be yours to make...

After choosing the format (1) according to its capacity to reproduce the bass without affecting the rest of the range, it is necessary to pay attention to the tweeter (2), the small high frequency speaker. The sound of the tweeter should be silky, because to hear as if you were there, the high notes should be like in real life. For example, a cymbal should not sound like a pie plate! It's all about the nuances and the high notes give the realism.

 Speakers, HOW MUCH TO INVEST?

Depending on whether you opt for a small-format speaker, known in the trade as a bookshelf, or a full-format speaker, the price range will vary greatly.

Based on what is currently recognized, here is a suggested budget for each category.

Once again, I propose 4 categories of buyers:

Beginner : For those who want to try listening to more than headphones, car radios, portable radios and so on.

Serious: For anyone who wants a more nuanced audiophile-type listening experience without investing too much.

Purists: For people who want to miss nothing in all the musical nuances, we are talking about feelings as much as precision listening, capturing the nuances with emotional attributes...

Audiophiles: Those who make it a real passion, for them there will be no compromise, it is the search for perfection...

Compact speakers :

• Beginner :

  350 to $499 per pair.

  Paradigm Atom se

• Serious:

  500 to $1199 per pair.

  Paradigm Premier 200

• Purists:

  1200 to $2699 per pair.

  Focal Aria 906

• Audiophiles:

  + 2700 per pair.

  Focal Kanta

Full size speakers :

• Beginners:

  800 to $1299 per pair. Paradigm Monitor 6000

• Serious:

  1300 to 2699 per pair. Focal Chora 826

• Purists:

  + 2700 per pair.

  Focal Aria 926

• Audiophiles:

  + 4500 per pair. Paradigm Founder 120H

The last word.

I hope you have found this exercise useful. You don't need to have a degree in engineering to acquire a sound system. Relying on professional advice and your ear will do the trick. Checking out forums is also a good source of information to validate your choices.

The more detours a manufacturer or dealer takes and the more pompous terminology they use, the more you should be wary and double-check. Of course, if you are comfortable with the terminology of the field, it will be a plus to be able to read or discuss the subject, but basically, human experience is everything!

Stay tuned!

- Christian