Has anyone tried or heard of Audio Technica AT-PHA55BT (ldac reciever) , or ampio m1 vx-1880, Bluetooth 5.0, aptx HD and ldac, any good?
Jan 1, 2018 at 9:55 AM Thread Starter Post #1 of 22
imparanoic

imparanoic

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Has anyone tried or heard of Audio Technica AT-PHA55BT (ldac reciever) , or ampio m1 vx-1880, Bluetooth 5.0, aptx HD and ldac receiver with 3.5mm jack, any good?

 
Jan 8, 2018 at 4:41 PM Post #2 of 22
I have ordered something similar - Audio Technica AT-PHA55BT. Specs. Review.
It is BT4.2 ldac/AAC/Aptx receiver based on ES9118 SABRE HiFi SoC with an impedance switch. I plan to use it with iFi iEMatch and xPeria XZ1 smartphone to listen to music through Echobox Finder X1 earphones and maybe later through something more green and andromedish.

at_0003_IMG_4159.jpg
 
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Jan 9, 2018 at 5:17 PM Post #3 of 22
I have found an article about ES9118 chip - according to it it sounds better then both LG G5 Hi-Fi module (ES9028 SABRE DAC and SABRE 9602 AMP) and LG V10 phone (ES9018 + SABRE9602), which is specs wise quite similar.

In one review, the sound of LG V10 was compared with number of DAPs and high end earphones and it was described as very clean, very detailed, but dry and with poor sense of space. It remained near dead silent even with very sensitive earphones. Mids were described as a bit aggresive and bass as a bit rough, a little poorly controlled and not hitting hard enough. Overall sound was described as lacking life and dynamics, and therefore it was adviced to pair V10 with more colour sounding earphones such as IE80 is. The verdict said, that the phone is perfectly suitable for use with mid tier (~300USD) earphones.

I would expect the same performance level (at best) with ldac units like these. Until an audiophile grade ldac portable receiver is released, it may function sufficiently.
 
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Jan 10, 2018 at 2:53 PM Post #6 of 22
If you have 2 Ldac players, then there is no need for AptxHD in my opinion. Ldac connected in Quality priority mode (990kbps) is somehow superior to AptxHD (576kbps) in transfer rate. For a while I wondered under what conditions is 990kbps throughput available on BT4.2 devices. They say the limit of BT4.2 is 650kbps, which is even less then Ldac Normal priority transfer rate of 660kbps. I think the explanation is hidden in this article, and I will quote it:

"There are two major parts to Sony’s LDAC. First is achieving a high enough Bluetooth transfer speed to reach 990 kbps, and the second is squeezing high resolution audio data into this bandwidth with a minimal loss in quality.

The first stage is accomplished by using Bluetooth’s in-house Enhanced Data Rate (EDR) option, which was introduced all the way back with Bluetooth 2.0 to increase maximum speeds. EDR speeds are not usually used by A2DP audio profiles, but the spec is rated up to 3 Mbps. Although in reality, 1.4 Mbps is mostly achievable, with 1 Mbps being considered the minimum stable connection. Hence why Sony’s LDAC sits just under this threshold at 990 kbps.

I should point out that EDR is an optional part of even newer Bluetooth 4.x devices, as the focus has been on decreasing power consumption for the most part. So not every chip, and therefore not every phone, will necessarily support Sony’s LDAC at the highest quality setting. Bluetooth 5 supports 2 Mbps low energy speeds out of the box, and is also backward compatible with EDR versions of Bluetooth, but again this higher speed is optional."​

As you see, all BT5 devices are backwards compatible with all BT4.2 devices, but you would need receiver that supports BT4.2 BR/EDR for smooth 990kbps operation, because BT4.2 LE (BLE) is capable only of max. theoretical 650kbps transfer rate, practically even less. Does AT-PHA55BT support BR/EDR? I do not know, maybe.

Ldac, which is lossy, should be able to transfer CD audio (16bit 44.kHz flac) without information loss because such flacs usualy fit in its 990kbps range. AptxHD will probably sound a hair more compressed with its 576kbps transfer rate. Ldac is also Sony made: there may be some benefits - maybe DSEE HX applied on receiving end? BT5 will provide you with even higher maximal throughput and distance and probably with less power consumption. See these 2 articles for detailed information: 1, 2. BT5 may, if I understand it correctly, lessen the amount of disruptions, that you would hear in areas highly polluted with WiFi network signals during use of Ldac in (highly demanding) Quality priority mode.

This is the hardware inside of Ampio products:
G1: Qualcomm CSR BT chip + dedicated TI PCM5102A DAC + TI TPA6133A2 amp . No mic.
P1+M1: Qualcomm CSR8675 BT chip (with Dac on chip) + TI TPA6133 amp.

Ampio G1 has no clip and it is bulky, which you may find impractical. The other two units do not have dedicated dac chip, but on the other hand, neither has AT-PHA55BT. Sound characteristics of DAC and AMP will be very important, so will be output impedance (AT has impedance switch - 16ohms/32ohm), amount if hiss, and quality of craftmanship. You can lower Output impedance and remove hiss with two iFi products: iEMatch and EarBuddy.

//
review of M1 and G1
review of P1
 
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Jan 11, 2018 at 5:20 AM Post #8 of 22
Similar products
Ldac earphones
  • i.Tech ProStereo H2 (BT4.2, Ldac, AptxHD, AKM+ DAC/Amplifier, see 1, 2 )
  • Sony WI-1000X (BT4.1, Ldac, AptxHD), Sony WI-H700 (BT4.1, Ldac, AptxHD, inferior to WI-1000X), Sony MDR-XB80BS (BT?.?, Ldac, Aptx)

Sony list.
Interview.
 
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Feb 27, 2018 at 10:08 AM Post #10 of 22
Just got M1 VS-1880 today.
The local price is ~140USD, with promotions.
I'm pairing it with Sony XZ premium (aptX HD / LDAC) and ASUS Z500KL tablet (aptX).

The fun of VS-1880 is that it supports all major BT audio codec to date.
The XZp can change the codec on the fly in developer options, so one can experiment with different codecs with one pair of devices.

Connections:
It did not solve the problem of skipping - when I enable the tethering on XZp and connects BT at the same time, the audio skips a lot, both on VS-1880 and former MUC-M2BT1.
However, there is no skipping problem when the BT is connected to the tablet, while the tablet is tethered to the XZp:
tablet <-- tethering --> XZp <-- LDAC (best-effort mode) --> VS1880 (skipping)
XZp <-- tethering --> tablet <-- aptX --> VS1880 (no skipping)
And yeah the interference can be avoided if tethering on 5GHz band, but why Sony did not provide that option is beyond me.

Sound:
I'm pairing VS-1880 with Beyerdynamic Xelento Remote, factory cable without mic.
LDAC did not lose much detail, compared to wired connection.
(without audio enhancements, but XZp headphone out is just meh...)
LDAC offers more detail and better treble extension than aptX HD.
aptX HD offers slightly more upper to middle-bass, quite "elastic" but not punchier, and can sometimes be funnier to listen to.
The noise floor is noticeable on VS-1880+Xelento, if you're curious.
I'll post more if there are more findings.
(sorry for bad English, not native to me :p)
 
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Jun 30, 2018 at 4:24 PM Post #11 of 22
myusernameislove said:
Similar products
Click to expand...

Hi, can anyone shed some light for me on this: some of the listed devices have a dedicated DAC, others don't - what difference does it make? Does it mean that if a BT receiver has a dedicated DAC, it is able to receive a non-decoded mp3 or flac stream and convert it to analog after transmission over BT? Or does the source device still have to decode an mp3 file into analog, then re-encode it to send it over via BT and then the BT receiver/amp decodes it again to send it to the earphones? I'm really lost here, I guess my real question is: if my Bluetooth receiver has its own dedicated DAC, does it still matter what DAC my phone has? Thank you.
 
Jun 30, 2018 at 5:15 PM Post #12 of 22
anton79ru said:
Hi, can anyone shed some light for me on this: some of the listed devices have a dedicated DAC, others don't - what difference does it make? Does it mean that if a BT receiver has a dedicated DAC, it is able to receive a non-decoded mp3 or flac stream and convert it to analog after transmission over BT? Or does the source device still have to decode an mp3 file into analog, then re-encode it to send it over via BT and then the BT receiver/amp decodes it again to send it to the earphones? I'm really lost here, I guess my real question is: if my Bluetooth receiver has its own dedicated DAC, does it still matter what DAC my phone has? Thank you.
Click to expand...
You use your phone’s dac to decode music when you listen through analog out = headphones jack.
Your phone encodes original music file into ldac or any other codec and sends these zeros and ones through bluetooth wave to bluetooth receiver which decodes it and plays it through analog out = headphones jack.
Dacs differ in this: different chip architecture, different strength (speed), different decoding software including intelligent guessing (reconstruction of lost information) how the wave is supposed to sound so that it does not sound unnatural. Codecs are losless or lossy, but original digital file is always lossy, because it captures soundwave only in certain number of points. etc.
 
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Jun 30, 2018 at 5:23 PM Post #13 of 22
dedicated dac = dedicated chip with architecture and software used only to decode digital to analogue.
All in one single onboard chip sollution (soc) = package of features performed by one chip, whose only one small part is meant to do decoding, other parts do bluetooth etc.
Real life scenario of how dedicated chip is implemented = get around the internal decoding mechanism and instead send the signal to second , dedicated chip to do the decoding. Challenge = do not alter filestream during the way (some single onboard chip sollutions apply some things that alter it, therefore dedicated chip use must be implemented properly) easy peasy? Nope.

Company named Chord uses custom chips for use with their own decoding software (trade secret), but most companies use common (cheaper) sollutions f.e. from ess as their dedicated chips. The more power computers gain these days, and the more clever decoding algorithms get, the better the sound you hear.
 
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Jun 30, 2018 at 5:43 PM Post #14 of 22
So basically some cheap portable dacs today probably sound better then most expensive dacs from 20 years ago. Not sure where it will go. Everything goes to multithreads, and chips get smaller and cheaper. Theoretically in 50 years some cheap dac may sound as well as Chord Dave, that is one of the best sounding dacs today.
 
Jun 30, 2018 at 5:52 PM Post #15 of 22
Thanks, it's getting clearer.

myusernameislove said:
Your phone encodes original music file into ldac or any other codec and sends these zeros and ones through bluetooth
Click to expand...

If we're talking about an original mp3 file, it's already a data file so the phone could theoretically send it over BT as is, but doesn't - instead, it uses its aptX (for example) codec to re-encode it into the format more optimized for BT transfer, and because the "pipeline width" of aptX expressed in conventional kbps exceeds the highest mp3 bitrate, such transfer should not result is a worse audio quality than if the original mp3 were decoded into analog.

Also, because the phone's DAC is not involved in the encoding of the mp3 by aptX, and it's the BT receiver's DAC that's responsible for the analog signal that goes to the earphones, if the BT device has a better DAC than the phone, I may end up with a better audio quality than if I just plugged my earphones into the phone audio out. Is my understanding correct?
 
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