Super Best Audio Friends

Just got the recently-announced Lumin U2 in for review. The U2 is solely a "streamer"; its function is to connect an upstream music server to a downstream DAC.

One of the nice things about the U2 is that it has two very useful new features that the U2 Mini and U1 don't have: an SFP-type optical transceiver port to allow connection via LC/LC optical fiber directly into the U2 from an upstream server (no need for potentially grungy and dirty copper Ethernet connections-gack! ), and a new "dedicated" USB port that is exceptionally quiet and...direct-coupled. This port's function is soley to connect to a USB DAC, rather than USB devices e.g. hard drives, flash media, etc.

Some pics:


I'm connecting to the U2 via LC/LC fiber from EtherREGEN in the remote server room, and the P1 with a USB cable.

It's only got about 70 hours or so on it, and it needs 500 hours to fully burn-in, but so far, I am very impressed. It's sounding very good, indeed.

More to come as I get more hours on it, stay tuned.

Let me get this out of the way first: the Grado HP100 is the most technically capable Grado to date.


I've directly compared the HP100 to the latest and greatest from RS1X, GS3000X, etc., and this takes the cake with respect to technicalities, that is clarity, resolution, smoothness, and bass extension. I am curious if and how the distortion measurements will indicate.

The HP100 SE comes with two different kinds of pads. The big salad bowl G pads and the flat F pads. For those not familiar, refer to this post on what the F pads do for various headphones in the Grado lineup.

Here is a simple guide to get started exercising at home with calisthenics (resistance training using only your bodyweight).

The sheer amount of fitness information online often leads to analysis paralysis, self-doubt, and a failure to build the consistency needed to make progress.



Fitness influencers thrive on content overload—because if they stop posting, they stop being relevant. That’s why there are 2,000 videos on how you're doing bicep curls 'wrong' and the one 'secret' to maximize your gains.

I got to hear one of the two new high-end releases from Raal recently and thought it might be worth creating a thread for them even though I doubt many here will be in the market for them.

I have been meaning to do a write up on the JBL 4367, but have been a bit lazy. It was @Xecuter who first turned our group on to these speakers, followed by @Jonah . I heard these at a dealer (courtesy of Koth and Ramesh) and came anway extremely impressed. It didn’t quite pull off the disappearing act and the wrap around staging and imaging like that of the summit-fi, narrow baffle speakers. I suspect it could have done a better job in a larger room with better treatments/acoustics.

Preamble
I have been out of the portable game for a while. The last DAP I owned (and loved) was the iBasso DX50. Later on I tried a number of dongles along with cheap and midrange IEMs and headphones. Most recently I have come to enjoy the iBasso DC-Elite, the iFi Audio Hip Dac 3 and Chord Mojo 2. I will attempt to compare the DX340 to these sources as they are the ones I am most familiar with.

For reference, out of the three dongles, the Chord Mojo 2 and iBasso DC-Elite were my favorite (quite a large performance delta when coming from the Hip Dac 3). The Mojo 2 has a wonderful sense of space, head stage, analog warmth and drive. The DC-Elite has noticeably less driving power, and so loves easy-to-drive headphones and IEMS. It has exceptional resolve, detail and clarity, along with PRAT.

Build and Usability
In regard to the DX340’s build and usability… I refuse to write up a review of the device itself, and want to keep this about the audio quality. That being said, I find the unit to be very heavy, well built and easy to use. I see this as more transportable than portable. I certainly can't fit it in my pocket and just use it at my desk or in bed. I have not had any noticeable issues with it, and I find the battery life reasonable, and the ability to change the gain for the DAC and Amp sections (along with the ability to drive the amp section with a 12v external power supply) to be a game changer.

I know some folks have asked about the Kara and I also know that a few members have already had it in their systems for a period of time. I've finally gotten to it. Honestly, not gonna bother with measurements because they are amazeballs per the Schiit APx555 report.



In a nutshell: Super transparent (way more so than the Freya S it replaces) and provides some oomph (while not as overly rich and colored as prior Nexus amps and preamps). I didn't want to believe it, but high-voltage rails are the real deal.

Three very similar 6AS7 based OTL design headphone amplifiers technical measurements will be compared. Measurement methods and notes can be found in this example post

The three amplifiers:

Woo WA3+ on the left
BH Crack in the middle
Xduoo TA-66 on the right

I began my journey into tube headphone amplifiers with the WA3+ and Sennheiser HD600 headphones. After years of enduring the headphone output of a Benchmark DAC1 which I used for dialog editing I found I could actually enjoy recreational listening when changing to a Violectric V800 and the WA3+. This was a revelation as I would not engage in recreational listening after work for many years. Too much listening fatigue from the DAC1.

I know some of you have been waiting a long time for a review of these and loaner. Yup, Chacha and I bad for holding on to them for so long. Yes, these are going on loaner ASAP.



Notes:

1. Not what I would say great channel matching. Considering the pads appear to be very uniform.
2. Even smoothed 1/9, response is a big jaggy and uneven. Can people hear this? Probably. It's hard to describe.

More measurements in a bit. D2 and D3 distortion surfaces around 8:42 in the video.

What sorcery is this? A couple of guys mentioned this little $250 Chi-Fi gem. OMG. This is not only is high-value Golden Schlong, but gets awfully close to an Excellence award if not outright deserving one.



The only thing I dislike is the clunky volume stepper - honestly I wished xDuoo just used a cheap pot - however I found the volume granularly acceptable with the HD800. Sure, many of us haven't heard of xDuoo because it's some of those oddball Chinese brands, but they've made decent stuff before: https://www.superbestaudiofriends.o...ble-dac-headamp-review-and-measurements.9655/

The CFA Fathom is a 6BA (2 tweeter, 2 midrange, 2 woofer) IEM housed in a black anodized body with rainbow shiny nipple ring things. Like all other CFA IEMS, it features MMCX connectors and comes stock with Time Stream cables in both 3.5mm and 4.4mm terminations. 11.7 Ohms at 1kHz impedance, 94 dB SPL at 1kHz: 6.75 mVrms, claimed.

Per popular request, context here. I have to say that I was curious too, as some readers mentioned, it has been "Wiim, Wiim, Wiim, Wiim" seemingly everywhere on the Internet.



I was a bit shocked that Lindsay, who is hardly an audiophile, came out so quickly against the Wiim in the video. I thought she'd save it for later....