Articles, Reviews and Measurements of Audio Products

AES conference program is finally available. I thought I post it for members to see what the buzz is about and whether there are any talks of interest: https://aesny23.sched.com/



You might see some familiar names there from ASR.

I am especially interested in the talk about B&K 5128 headphone preference curves/listening tests. Author had contacted me in advance about it.

This is a review, listening tests and detailed measurements of the Weiss DAC501 balanced DAC, headphone amp and network renderer. It is on kind loan from a member and costs US $9995.

The case is fine enough but not nearly so for what it costs. Stamped steel should have no place in this price range. The LCD is decent size but not very high resolution. It is touch sensitive but wasn't easy to navigate using that. It uses inverse scrolling in that to move the menus up, you rotate the knob to the left, not right. Fortunately a remote control is provided which allows quick random access to inputs and such. Back panel shows what you would expect as far as connectivity:


What distinguishes this streamer becomes visible once you...

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?).

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:

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...

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.

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:



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...

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.

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...

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.

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.

Making...

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! Here is the Schiit version:

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...

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.

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:

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...

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.

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:


SINAD of...

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).

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:


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):


We are heavily distortion limited. 2nd harmonic is dominant by far. Noise level is actually good:


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