Articles, Reviews and Measurements of Audio Products

Meyer Sound Amie Monitor Review

  • 14,512
  • 158
This is a review, listening test and detailed measurements of the Meyer Sound Amie Studio (active) monitor speaker. It is on kind loan from a member and costs US $4,080 each (sold in pairs?).
Meyer Sound Amie Studio Active Monitor Speaker Review.jpg

The deep, horn like waveguide sets the speaker apart from its competitors. The large throat of the port and larger than normal enclosure (relative to its woofer) imparts similar feeling. Speaker is not that heavy despite having a large heatsink on the back:
Meyer Sound Amie Studio Active Monitor Speaker back panel Review.jpg

As you see, or rather don't, there is only a balanced input and speakon type connector for power. There are no controls for gain, bass, treble, etc. I am fine and actually happy with the latter two but did wish to have a gain setting. Driving the speaker at 0 dbu on the first test, I nearly jumped out of my chair in how loud the...

Buckeye NC252MP Stereo Amplifier Review

  • 33,143
  • 361
This is a review and detailed measurements of the Buckeye NC252MP balanced stereo class D amplifier. It was kindly drop shipped to me by a member and costs US $575.
Buckeye NC252MP Hypex Class D stereo amplifier review.jpg

The amp is almost the size of a loaf of bread and literally weighs nearly as much! Amazing how far amplification technology has come. The package is made to be economical and intended to be heard than seen. Back panel is what you expect to see with notable inclusion of trigger input to automatically power the amp from the source:

Buckeye NC252MP Hypex Class D stereo amplifier balanced back panel review.jpg

If you are not familiar with the tests that are about to follow, please watch my video on understanding amplifier measurements.

Buckeye NC252MP Amplifier Measurements
We start with our 5 watt dashboard...

RSL C34E MKII In-Ceiling Speaker Review

  • 9,680
  • 46
This is a review and detailed measurements of the RSL C34E MKII architectural, home theater speaker. I purchased it for testing and costs US $149.
RSL C34E MKII in-ceiling in-wall home theater surround speaker architectural review.jpg

Please excuse the stock picture. Speaker is still on an ugly baffle on Klippel NFS. As this type of speaker goes, the C34E MKII is lighter than others I have tested. Instead of one large and heavy woofer, two smaller mid-woofers are deployed at an angle. I was not a fan of the rotating tabs in the back as they did not extend past the edge of the rim. This means if you cut your hole a bit too big, they won't bite. There is a diagram that I think shows you can rotate them but I did not mess with that.

Measurements are performed without the grill using the "baffle" mode of Klippel NFS where the system computationally eliminates the back wave and diffraction from edge of my mounting board. The result is...

Revel C783 In-Ceiling Speaker Review

  • 9,151
  • 47
This is a review and detailed measurements of the Revel C783 in-ceiling speaker. Was kindly sent to me new by a member and costs US $ 660 each.
Revel C783 In-wall in-ceiling speaker review.jpg

You are seeing the speaker as mounted in my temporary MDF baffle for measurements. There are two switches to control level of bass and treble (I measured the former). It said tweeter is adjustable but I did not try and tested it head on.

Usually the mounting screws are threaded to the tab behind so relatively easy to tighten. Not here. They were thread forming (into plastic) so took fair bit of power to screw them in. That by itself is not a big deal but there is always the danger of the screwdriver slipping and tearing up the woofer. And it is not fun doing this on while working on the ceiling., I had to find the right phillips screwdriver so that it would not slip. Otherwise, speaker seems well made and comes with magnetic grills.


Schiit KARA Preamp and Headphone Amp Review

  • 37,429
  • 236
This is a review, listening tests and detailed measurements of the Schiit KARA balanced preamplifier and headphone amp with stepped relay control. It was sent to me by the company and costs US $699.

Oh wait... that is the picture of our dog, Kara! :D Here is the Schiit version:
Schiit Kara Balanced Preamplifier Headphone Amplifier review.jpg

As I have mentioned before, I am a fan of the elongated Schiit products. It gives them a slick look. Controls are logic controlled and there is a pause as you change gain. As noted, volume knob controls a set of relays for attenuation, producing matching channel response. The relays act very quickly which is good as far as keeping the muting low as you crank the knob. The mechanical sound though is of "bizzing" nature so not very pleasant if you are close to the unit. Labels use mnemonics that are hard to decipher at first but you learn them...

Role Audio Skiff Speaker Review

  • 15,251
  • 152
This is a review, listening tests, EQ, and detailed measurements of the Role Audio Skiff compact speaker. It is on kind loan from a member and costs US $495 to $545 a pair depending on finish.
Role Skiff Near-field point source single driver speaker review.jpg

Can't say there is much to look at especially since the grill is glued/screwed on and can't be removed. It is stated (I think) that it is a single 3" driver with no crossover. Enclosure is 4x6 inches and 5 inches deep -- so quite compact. Back panel shows nothing exciting:
Role Skiff Near-field point source single driver speaker back panel review.jpg

Speaker came out circa 2000s but it is still being manufactured and sold.

Role Skiff Speaker Measurement
As usual, we start with our anechoic frequency responses:
[ATTACH type="full" alt="Role Skiff Near-field point source single driver speaker frequency response...

TempoTec Sonata BHD Pro Portable DAC & Amp Review

  • 35,744
  • 196
This is a review and detailed measurements of the TempoTec Sonata BHD Pro portable DAC and headphone amplifier. It was sent to me by the company and costs US $70.
TempoTec Sonata BHD balanced dac and headphone amplifier review.jpg

I really like the fresh look of the BHD. There is a red LED that lights up the tiny ICs in there, giving it some elegance. There are volume control buttons on the side with good tactile feedback. And from what I could see in measurements, they have fine resolution.

Importantly there is support for 4.4 mm balanced headphone out in addition to 3.5mm.

EDIT: I originally left out "Pro" out of the name. Corrected some but the rest of the graphs are still missing that word in the model name.

TempoTec Sonata BHD Pro Measurements​

Let's start with our dashboard using balanced output:
TempoTec Sonata BHD balanced dac and headphone amplifier.png

SINAD of...

EAR Yoshino 834L Deluxe Preamp Review

  • 42,657
  • 582
This is a review and detailed measurements of the Ear Yoshino 834L Deluxe Tube (Valve) stereo preamp designed by Tim De Paravicini. It is on kind loan from a member and costs US $3095 (£2,699.00).
Ear 834L tube preamp stereo valve review.jpg

I am not a fan of chrome front panel but realize this is a personal thing. The case is stamped sheet metal which feels cheap compared to that. Controls are large and easy to manipulate.

Back panel sports gold plated RCAs but they seem kind of tarnished/dull:
Ear 834L tube preamp stereo valve back panel review.jpg

Note much else to say than let's measure it.

Ear Yoshino 834L Deluxe Tube (Valve) Preamp Measurements
As usual, we set the input to 2 volts and adjust the volume for "unity gain" (same output voltage):
Ear 834L tube preamp measurement.png

We are heavily distortion limited. 2nd harmonic is dominant by far. Noise level is actually good:
Ear 834L tube preamp SNR stereo measurement.png

I was impressed by the wide bandwidth but found the very low frequency rise...

Sony MDR-Z1R Headphone Review

  • 14,399
  • 92

Measurement Conditions Explanation And Chart Interpretation Of Cuckoo Studio Review​

We have received the Sony MDR-Z1R headphones sent by WSGM. appreciate his support for the channel.


The Z1R comes in two versions: the in-ear version called IER-Z1R and the over-ear version called MDR-Z1R. Both of them are quite expensive, with the over-ear version consistently priced around $1500. The design direction of the MDR-Z1R is minimalist. It features an all-black body with no flashy elements. However, the large, non-centrally symmetrical raised fine mesh grille on the back gives it a strong sense of identity while remaining understated.

[ATTACH type="full"...

Toslink switch and TosLink/Coaxial SPDIF converter - Review and measurements

  • 13,178
  • 74
I measure-checked 2 digital Toslink devices :
Toslink switch + Bi-directional TosLink/Coaxial SPDIF converter


I needed to extend my digital inputs capacity for home living room and another location.
So I purchased
- a 3 inputs - 1 output small TosLink switch - with remote. (30€ - Audiophonics)
- a bi-directional Coaxial/TosLink SPDIF converter (26€ -

Both are pure digital SPDIF devices.
No DAC or ADC here.

As you may see on the picture, those are VERY small devices.
Even the remote is tiny, compared to the XLR connector that holds it straight.


The TosLink switch has 3 inputs and 1 output.
Input may be selected through the remote or the front switch.

The Coaxial/TosLink SPDIF converter has a coaxial SPDIF (RCA connector) and a Toslink on both sides...
Top Bottom