Articles, Reviews and Measurements of Audio Products

This is a review and detailed measurements of the SMSL SU-10 Balanced DAC with Bluetooth. It was sent to me by the company and costs US $900.

Front panel is smooth and slick and sports the new colorful display from SMSL with large volume level which I very much appreciate. Interestingly volume goes up another 2 dB (or so) so you have a bit of headroom. Back panel shows some new features:

For the first time we have a choice of USB-B and -c inputs which you can select from the menu. Another new feature is ability to turn on the balanced or RCA outputs independently or together. Nice!

The high cost is partially due to use of not one, but two ESS ES9038Pro DAC chips. The 8 channels in each chip is combined to get the best dynamic range for each channel.

Based on company recommendation, I upgraded the unit to latest firmware.

SMSL SU-10 Measurements
Let's start with our usual balanced output after...

Hello you all.

Some of you may have noticed that I have slowed way down in reviews and posts. The major reason for this is that we are getting our older home ready for sale and it is in another city. So I have to keep going there and stay until I get things done. By the time I get back home, a ton of stuff is piled on here as well. The list of things to do seems infinite and so little time to get them done. I will try to squeeze a review here and there but that will be it until we come out of the tunnel on these projects.

Above also means very slow response in messages especially if the answer is not a quick one. As I look now, it says I have 39 unread messages!!!

This is the deepest hole I have found myself in, in a long time. Fortunately good progress is being made to take care of things. So in balance I feel fine but just not able to keep up with the forum.

I expect this to continue for the next 4+ weeks. Appreciate your understanding.

This is a review and detailed measurements of the SMSL M500 MKIII balanced DAC and stereo headphone amplifier. It was sent to me by the company and costs US $530.

While the formfactor remains the same as previous generations, the display is upgraded to have high contrast and attractive color. Great that volume level if emphasized. The processor behind the display is also very performant with great volume control display rate and acceleration support. Navigation is simple using the included remote:


A couple of minor complaints though: the USB connector is too close tot he upside down XLR jack which made it impossible to push its pin in with the USB cable attached to right channel. Also, I like to see red for right channel on RCA connector. Otherwise, included power supply is...

This is a review, listening tests and detailed measurements of the RAAL requisite CA-1a "true ribbon" headphone. It is on kind loan from a member and costs US $2,500.

While the RAAL SR1a required a massive power amplifier, the revised transformer can be driven from a high-power headphone amplifier which is a major improvement. The CA-1a feels more comfortable in hand but looks primitive and more like a prototype than real production. The pad especially gives that feeling as it looks like cheap open cell foam that would fall apart if left in the sun for a few days! Two sets of pads are provided: one provides full seal and the other has slots above and below.

Headband only has two sets of adjustments. While this mostly fit my head, it may not be enough range for everyone...

Hi folks,

Hello everyone. Good suggestion was made to post the various titles we have on the forum. Some are obvious, some are not so. Here they are.

Founder/Admin = Amir’s Account Tag. Owner, Creator of ASR.

CFO (Chief Fun Officer) = Amir’s Tag.

Administrative = I don’t usually login under this but it is what it says it is.

Audio Luminary = Assigned to Members whom are recognized industry wide as Audio Professionals and Specialists. Have Published various Audio Engineering Works and/or hold Patents or were instrumental in the development and design of various Audio technologies. Were or are Foundational Leaders in the Field of Audio Science and Engineering. Requires a very high bar to be granted. These Members are considered Highly Valued and Honored ASR guests.

Dealer = Assigned to Members who Represent a Commercial Audio Product(s) dealer/distributor for retail sales. Have no affiliation with ASR other than a Guest Vendor.

Editor = Assigned...

I will give a short introduction via simulations in COMSOL Multiphysics to the ‘Double Array Bass’ subwoofer setup and how the response will differ between an idealized situation of two walls moving compared to having a finite number of subwoofers.

Imagine first a 3x4x5 meters room. We can calculate the associated room modes as shown below.


These modes are an inherent feature of the room geometry and air being the medium inside it. They exist independent of any sources and are calculated without any regard to sourcing. Whether a mode is a problem or not will be evaluated when a source(s) is activated. Let us now put a subwoofer in the corner and evaluate the sound pressure level in 6 preselected places at a height of 1.1 meters.



The responses in the points vary quite a bit.
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This is a review and detailed measurements of the boXem Audio Arthur 4222/E1 mono power amplifier. It was sent to me by the company and costs €1,490.00.

The design is quintessential European with gray body and colorful front panel which I like. The only power button is on the back:

Fortunately you have trigger input so you can set it to power up when the source turns on. Three gain settings are provided which is very nice. Unlike some amps in its class, it has both XLR balanced and RCA unbalanced inputs.

The amplifier is class D and is based on Purifi 1ET7040SA module.

EDIT: amp is 4222, not 4215.

boXem Arthur 4222/E1 Measurements
I started with the input gain set to low:
...

Kenwood L-08C Pre-Amplifier Measurements (Vintage Audio)

Part 1: Kenwood L-08M Monoblock Amplifier Review

If you haven't read Part 1, please give that a read first. There's a much better description of the history of this product line in part one. If you haven't read Part 1 and just want to continue, then spoiler alert... the L-08M was coming surprisingly close to the type of performance we get from HypeX NC500 amplifieres, made more impressive since this was achieved in 1980 with the benefits of 1V input sensitivity and the higher gain and 2 years before the compact disc.

What about the matching L-08C pre-amp? This L-08C was recapped and restored by Peter at QuirkAudio. Thankfully, while the pre-amp is made with a lot of...

This is a review and detailed measurements of the Sutherland KC Vibe MK2 phono preamplifier. It is on kind loan from a member and costs US $999:

The box is quite substantial and deep despite the fact that power supply is switching and external:

Where do you think the power supply plugs in? You would never guess. It is through a hole underneath! I suspect that optimized the circuit layout together with disjointed inputs and outputs.

The power supply is rated at 48 volts so hopefully that translates into good bit of headroom.

Gain and loading is programmable but sadly through jumpers inside the box:


I went with the recommended 45 dB gain for the measurements.

Sutherland KC Vibe MK2 Measurements
Let's start with our usual dashboard:

Very nice to see no distortion spikes which is my target. Noise is controlled enough to almost...