Have I just been living under a rock or why the hell haven't I heard about this before now!?

https://www.njr.com/MUSES/index.html

The shift of the center of gravity of the high end from component, rack systems to portable continues. Exhibit A

I've also noticed that over the last couple of years the basic blueprint for a portable headphone amplifier as defined by the Sony PHA-1 has now been taken up by all of the major Japanese audio companies.

Sony PHA-1, PHA-2, PHA-3
Denon DA-10
Onkyo DAC-HA200 and TEAC HA-P50 (variants of the same basic unit)
JVC SU-AX7 (report) (seems to be mostly Kenwood DNA)
Audio Technica AT-PHA100
and Fostex hp-p1

For all the above you are looking at a battery powered, slim-cased DAC + headphone amp typically with some sort of guard around the controls. They all feature a good variety of analog and digital inputs, offer switchable gains, and are priced over a range from $200 to nearly $1000.

You are looking at the convenience of having the DAC built in, the small size, and the rechargeable lithium...

Eye candy.

My fourth. Each one comes packaged the same, with a serial number and individual calibration sheet.

This little guy is no. 2096, .39/.40 mV. Signed off by Mr. Nemoto (根本さん、ご苦労様！)

What we are looking at here is the Fast Fourrier Transform (FFT) of the line output from my b-board buffer recorded at 24 bit, 96 kHz by an Onkyo SE-200PCI sound card. Upstream from the b-board is the Phonoclone 3 MC phono stage, connected to a Denon DL-103. The tonearm is Denon DA-307, and the deck is a Denon DP-2000.

Four recordings, taken 1) with music playing, 2) with the tonearm raised 3) with the phonoclone powered off and 4) with the b-board and all upstream components powered off.

True 24/96 data was obtained, measurements out to 48 kHz are possible, with -130 dB noise floor. (I was using Digionsound 6 to do the recording as Audacity truncates 24 bit recordings to 16 bit in Windows due to licensing issues. The FFT was generated in Audacity however.)

The soundcard's line input may have an impressive-looking low noise floor, but it's still useless for measuring line level audio devices like the b-board because the noise of the preamp/ADC...

I suppose everyone has at one point or another adjusted the volume sliders in Windows. The ones that go from 0-100, and you are never quite sure what whether its a boost, or an attenuation, or what.

Some years ago I measured the outputs and inputs using a fixed amplitude .wav file created in audacity and played back through the Onkyo SE-200PCI. I've taken another look at the worksheet I made and I've noticed that the volume settings correspond to very logical, even steps, namely:

100 0 dB
90 -1 dB
80 -2 dB
70 -3 dB
60 -4.5 dB
50 -6 dB
40 -8 dB
30 -10 dB
20 -14 dB
10 -20 dB

or for the mathematically inclined: 20*log(volume/100)

This scale is the same for both the output master volume and the line input, so its probably maintained throughout the operating system.

So now you know.

** note added much later,

My new soundcard,...

Part I is here.

Setup notes are in part I. Listening system downstream is the Sapphire headphone amplifier and Sennheiser HD-600 headphones. As the SE-300's line output routes though the Windows sound mixer, while the SE-200's bypasses it, it was not possible to keep the headphone amplifier volume at a constant setting between cards. Since I found the built-in headphone amplifier of the SE-300 to be good but not at the level of the Sapphire, only the stereo RCA output is being reviewed here.

Let me begin by saying that Windows is fundamentally an anti-audiophile proverbial dog's breakfast of setting and driver layers (quick, what's the difference between the DirectX and WaveOut sound modules?), and most soundcards are also anti-audiophile in that they cater to gamers and casual listening with a full barrel of virtualization, equalization, and reverb features enabled by default.* No surprise then that both cards require careful setup to sound their best, or,...

When I upgraded my computer recently I accidentally bought a motherboard with no PCI slots which meant I could no longer use my SE-200PCI card, my main reference source now for some years. Rather than switch motherboards again I figured I'd try Onkyo's latest version which has been out for a while now, the SE-300PCIe. I picked up a used "R2" model for $200.

I mention the price up front because the cost of this thing outside of Japan is astronomical. I've seen asking prices of $450 US! In Japan the retail price is about $300 in most stores. That's still very expensive. Despite the good things I have to say about it, the cost/performance must be taken into account based on the particular price you are looking at paying.

This is a Japan-only product, so the web site is Japanese:

main page (gallery)

The basic specs for the stereo line output is 120 dB S/N A weighted, 24/192 capable, 0.3-88kHz -3dB for the 2 channel stereo...

Original article, by Ben Popper

~ my spin ~

There was the iPod. It was cool, and the distinctive while earbuds that came with it showed people you had an iPod, so they were cool, too. A few audiophiles invested in better IEMs, but they tended to be expensive and discreet and anyway were only ever a niche thing.

Meanwhile the Japanese headphone makers - JVC-Kenwood, Sony, Audio Technica - tried competing with the iPod, and they came up with a spectrum of earbuds and headphones of every shape, price, and color. They sold as commodities, but none developed any real kind of identity or reputation. Certainly there was little effort at building a brand.

On the other side, Grado, AKG, and Sennheiser continued doing pretty much what they always did, making nice, expensive headphones for home/studio/DJ use.

Neither group addressed the obvious hole in the market: non-audiophiles wanting "good" sounding over-ear...

The Technics SU-9070 is a 2U rack mount stereo preamplifier from 1977, matched to the SE-9060 amplifier. The preamp was sold as the SU-9070II in Japan.

The circuit is shown below, for educational purposes.

The power supply regulation is quite elegant, I hope to get to that in a future post. Here, just note that there are separate regulated lines for the MC stage, the input/VAS sections of the MM and line amps, and the output sections of the MM and line amps.

There was a series of relatively slim (2U chassis rather than 4U), upmarket audio separates put out by Technics in 1977: the ST-9030T tuner, SU-9070 preamplifier, and SE-9060 amplifier. They are two degrees of separation from the top of the line models at the time, the range went 9600>9200>90x0.

I recently acquired the tuner (more on that some other time) and have the others in my sights.

For educational purposes, the amplifier schematic for the SE-9060 is shown below. The input stage and voltage amplifier was driven from regulated 55 V supplies (Va+ Va-), while the driver stage was powered directly by the rectified DC at about 50 V (Vb+ Vb-) filtered with 18,000 uF per rail per channel.

Note that there were 9060 and 9060II as well as 9070 and 9070II models in Japan, but the export model of the preamp which sold as the 9070 was actually the 9070II rather than the 9070 domestic version. Likewise the SE-9060 shown below (from a European...