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Alpha Audio’s testing policy – 2022 update

Alpha measurement system

We thought it was time to give you an update on how we work at Alpha Audio. A lot has changed in the last two and a half years. So it’s useful to give you some insight into exactly how we operate

Over the past few years we have invested heavily in recording and measurement equipment. Just before Corona time – November 2019 – we started building and developing the sampling set-up so that we could offer you more ‘experience’ over the internet. That set-up has remained because it has proven to be a very useful addition to the reviews during the Corona period. Now that we already have a whole database of samples we will continue to create and make available samples and live stream reviews.

Prism dScope

In early 2022, we realized a long-held dream: the purchase of a Prism dScope III. A high-res measuring device, specifically for audio equipment, that allows us to measure virtually any piece of electronics. Both analogue and digital. And that up to 24 bit / 192 kHz. In short: a very useful device for collecting objective data. The Prism has already shown its added value in several reviews. We hope that it can provide us with beautiful insights for years to come. Besides the Prism dScope we also use a dummy load (4 and 8 Ohm), a variable resistor (1 – 33 Ohm, 3A max) and a Rigol scope. This scope can handle a higher bandwidth so we can see other things. Think of risetime / HF noise, etc.

What do we test with the Prism dscope?

  • Noise floor
  • Signal to noise ratio
  • Channel separation
  • Frequency Response
  • Impulse Behavior
    • (together with the Rigol scope and usually the Sonnet dac – NOS and thus no ringing)
  • Linearity
  • Power (4 + 8 Ohm)
  • Jitter
  • Distortion (IMD, THD, THD+N)

We are also working on developing a thorough test for power supplies and power conditioning. We can already measure the noise in the spectrum up to 100 kHz. But we need to develop a better test signal so that we can see the impact of a filter on, for example, impulse behavior.

Sourcetronic LCR

Last weekend we made a new purchase: a Sourcetronic LCR meter. A high-end LCR meter with a precision of 0.05%! And a wonderful software package with it so we can put nice screenshots and graphs in the articles.

An LCR meter measures among other things: resistance, impedance, capacitance, inductance, conductance and for example Q factor. What is the use of this? Simple: we can start measuring cables, for example. Right… cabling… but really good.

This too is a long-cherished dream, because in this sector in particular a lot of nonsense is being peddled. We know that there are manufacturers who do real research and deliver solid products. And we estimate that there are also things that are demonstrably better. But there are also brands that come up with solutions for non-existing problems. In short: from now on we will also subject these products to an objective measurement. This is to help you make a sound choice. After all, you can only spend your hard-earned money once, can’t you?

What we also want to try with this LCR is measuring impedance of speakers. But then ultra-precise. It is possible with the Prism, but that is a bit complex. Perhaps it is easier with this LCR meter.

What do we test with the Sourcetronic LCR?

We haven’t run any tests at the time of writing – it has yet to arrive – but we want to test the following:

  • Capacitance
  • Resistance
  • Inductance
  • Conductance
  • Degree of shielding (if applicable)
  • All within a bandwidth of 20 Hz – 300 kHz (sweeps with 801 points)

These characteristics have a direct impact on the reproduction. In short: deviations should be audible.

What else do we want to add?

Another wish is the addition of a relatively dead room and a CLIO 12. That would complete the list. But anyway: a good measuring room for speakers requires space; lots of space. And that space must then be made suitable for measurements. And unfortunately a CLIO 12 is not cheap.

What does a complete review look like?

To give you an idea of the steps of a complete review, we have simplified the steps and put them together.

  1. Product arrival at the editorial office in Haarlem
  2. Unpacking and setting up
  3. Listening
  4. Pictures / video (video is optional)
  5. Sample video (if useful and possible)
  6. Measurements
  7. Writing

This is the most complete review. However, this is only possible if the product arrives in Haarlem and we get enough time for a review. If the product is delivered to an author’s home, measurements and samples are not always possible. This because of logistical reasons (and time). Then a review looks like this.

  1. Coming in outside of Haarlem office
  2. Unpacking and setting up
  3. Listening
  4. Pictures
  5. Writing

Painting a complete picture

Alpha Audio’s goal is to describe a product as accurately as possible. And to do that, we want to combine our own subjective findings with objective measurements and samples that give an impression of the reproduction. In this way you can read and hear what a product does.

PS: these developments and investments are made possible in part by our Patreon members!

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