Saturday, 17 April 2021
REVIEW / MEASUREMENTS: Drop + THX AAA 789 Linear Headphone Amplifier. And on Audioholics' THX Onyx DAC/amp "review" with a dash of MQA nonsense...
Saturday, 10 April 2021
REVIEW / MEASUREMENTS: AKG K371 (closed-back, over-ear, dynamic driver) - An affordable, modern, standard studio headphone. (And on using the miniDSP [H]EARS rig.)
First let me show you some pictures of these particular headphones, and later, we'll get into measurements with the inexpensive miniDSP (H)EARS test fixture.
Saturday, 3 April 2021
MEASUREMENTS: Melody Onix SP3 Mk. II (~2006) Class AB Tube Integrated Amplifier. (And it isn't "diminishing returns" on sound quality, often there are simply "no returns".)
Saturday, 27 March 2021
MEASUREMENTS / MUSINGS: Headphone impedance, sensitivity, efficiency, and amplifier output impedance. (And a quick thought on Darko's "All You Need Is...")
Some people have walls of headphones. Well the other day I thought I'd take out my little collection accumulated over the last few decades around the house, some of them used by the kids, and let's dump them on the sound room ottoman to have a look :-).
The majority are based on dynamic drivers with a couple of balanced armatures (Etymotic ER-4, 1MORE Quad Driver). I'm actually missing a few there that were in use that evening by others around the home - the Dekoni Blue (an officially sanctioned "modded" Fostex T50RP Mk 3) planar-magnetic, the AKG K371, and Apple AirPods Pro (wireless) which my wife had brought to work and "forgot" to bring home that evening.
I was curious about the impedances of these devices and thought it would be good to put together a summary article looking at this along with the power needed to drive headphones and correlating these characteristics with amplification.
Although I have spoken of the importance of mobile audio in the past, I really have been remiss in not putting enough emphasis on this trend or the importance of headphones in these blog pages over the years. Despite this, some of the most common E-mails I've received over the years have actually been about headphones. So let's make sure to incorporate some "head-fi" in the days ahead!
Saturday, 20 March 2021
A reader awhile back had the need to do some hardware work on the Audio Precision APx555 B-Series machine and in the process, was able to take a few photos of the innards, sharing it with me. The B-Series audio analyzer is the latest and greatest audio measurement device from AP. It was announced in December 2018 and here's a nice review from 2019 in audioXpress.
Saturday, 13 March 2021
HOW-TO: Partial Frequency Correction with Acourate. Spotify HiFi coming and a look at the evolution of music sales/formats from 1980-2020.
Friday, 5 March 2021
RETRO-MEASURE: Pioneer CT-S605 Cassette Recorder/Player (1989). On cassette quality / fidelity. Cassettes are "coming back"? And sentimental associations...
After the usual recent posts on DACs, DSP, speaker measurements, let's discuss something very different this week!
Within this collection were some made in the mid-'80s until about the mid-'90s when affordable CD burners (~$500 I think around 1996) came on the market and I quickly shifted to making "mix-CDs" rather than mix tapes. In fact, I found some almost brand new tapes that I forgot I still had:
|Left: Fuji DR-I standard Type I Fe2O3 "Normal Bias". Right: Maxell XL II Type II CrO2 "High Bias". Center: Sony Metal-SR basic level Type IV "Metal Bias" for "Digital Excellence" - back in the day :-).|
Saturday, 27 February 2021
MEASUREMENTS: Emotiva Airmotiv B1+ bookshelf speakers. A comment about Andrew Robinson's Fluance Reference XL8S video review and "Do measurements ultimately matter?".
|Emotiva Airmotiv B1+: Comes with small manual, and some stick-on rubber footers in the plastic bag. Fabric covers in background.|
Saturday, 20 February 2021
REVIEW / MEASUREMENTS: HiFiBerry DSP Add-On with the DAC2 HD. A quick Roon 1.8 network/endpoint issue and remote access request.
This post is in many ways a continuation of the HiFiBerry DAC2 HD measurements presented last time with the devices sent to me by Doug Gardner for testing. For some background, this DSP Add-on is related to the BeoCreate project which was documented in this 2018 thesis in collaboration with Bang & Olufsen. The idea was to create an open-source system to allow consumers to build or update their own loudspeakers to be active devices. It looks like this DSP Add-On board leverages that software to do its magic.
As you can see in the thesis, the final BeoCreate product was a board which included 4-channel amplified outputs, digital S/PDIF input and output, DAC, and of course the programmable DSP subsystem. A Raspberry Pi could be added to provide network streaming capabilities.
For completeness, I want to mention that this DSP Add-On is also compatible with HiFiBerry's DAC2 Pro (~US$50-60) board. Notice that the DAC2 Pro is a less expensive DAC than the DAC2 HD and sports headphone out. The converter chip seems to be the TI PCM5122 (same as previous gen DAC+ Pro) based on what's listed in the specs sheet but I have not seen confirmation that is indeed the case.
Saturday, 13 February 2021
Saturday, 6 February 2021
RETRO-MEASURE: Spendor SA1 (1976) monitor bookshelf speakers (The foam tweeter ring tweak!? And on "Listen For Yourself!".)
Saturday, 30 January 2021
REVIEW/MEASUREMENTS: SMSL (S.M.S.L.) M100 Mk II Hi-Res DAC (USB, S/PDIF Toslink and Coaxial In, ESS Sabre 9018Q2C, below US$100)
[Disclosure: Over the years, I have measured and reviewed products I have either bought or borrowed from friends. The product discussed in this post was sent to me by Aoshida Audio for an honest review and impressions which I can keep to use. It would only be fair that I provide the free shipping and "lowest price guarantee" links to Aoshida if readers want to purchase this DAC or others discussed. Considering that a major part of my review process is objective in nature and standardized over many years, I trust that much of what I present will remain free of bias. Note that I will be selective of what I agree to measure/review of this nature - accessible and high fidelity products that might be of interest to readers, or more innovative devices will obviously be most appropriate for what I do.]
As you can see in the image above, today let's have a look at another very inexpensive DAC product from S.M.S.L. with high-resolution ability. Over the years, I have reviewed/measured other devices from this company including the SMSL A6 integrated amp, the SMSL iDEA DAC, and more recently I've been enjoying the SMSL SA300 Class-D desktop amplifier. These are examples of "accessible" audio products, well within the price range of basically any music lover, "audiophile" or not.
So it is with this DAC. The S.M.S.L. M100 Mk II currently costs less than US$95, needs little power, and accepts USB/TosLink/Coax S/PDIF inputs. As you can see, it's shaped as a rectangular prism. The size is smaller than the photo might suggest measuring at about 2 1/8" x 2 1/4" x 3 5/8" long, weighing around 0.5lb (250gm). The enclosure is aluminum with shiny plexiglass front panel; the package feel solid. Inside the box is an assortment of printed manuals in English, Chinese and Japanese along with a basic white USB-A to micro-USB cable.