# 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?



## imparanoic

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?


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## myusernameislove (Jan 11, 2018)

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.


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## myusernameislove (Jan 9, 2018)

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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## imparanoic

this is perfect for me

i will order one


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## imparanoic

i want one with ldac ( which i have on my walkman nw-zx100 and sony xperia XZs phone) or should i wait for future models with aptx hd and bluetooth 5.0


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## myusernameislove (Jan 11, 2018)

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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## imparanoic

Great info“thx


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## myusernameislove (Jan 17, 2018)

Similar products

Ldac receivers: FiiO BTR3 (announced for 2018), Sony MUC-M2BT1 (BT4.1 earphone cable that supports Ldac, ?dac ?amp - review).
Notable AptxHD receivers: Bluewave GET (BT?.?, *CSR 8675 chip*) , Astell&Kern AK XB10 (BT4.1, ?dac ?amp), Radsone EarStudio ES100 (BT?.?, *CSR 8675 chip* +* 2x AK4375a DACs*) etc.
Notable Aptx receivers: FiiO BTR1 (good value for money, BT4.2, *AK4376 DAC*), CEntrance BlueDAC (BT?.?, VelvetSound™ *AK4490 DAC* coupled with *CEntrance AmpExtreme* Class-A Headphone Amplifier) etc.
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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## myusernameislove

Dedicated thread for AT-PHA55BT


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## mikescchen (Feb 27, 2018)

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 )


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## anton79ru

myusernameislove said:


> Similar products
> 
> Ldac receivers: FiiO BTR3 (announced for 2018), Sony MUC-M2BT1 (BT4.1 earphone cable that supports Ldac, ?dac ?amp - review).
> Notable AptxHD receivers: Bluewave GET (BT?.?, *CSR 8675 chip*) , Astell&Kern AK XB10 (BT4.1, ?dac ?amp), Radsone EarStudio ES100 (BT?.?, *CSR 8675 chip* +* 2x AK4375a DACs*) etc.
> Notable Aptx receivers: FiiO BTR1 (good value for money, BT4.2, *AK4376 DAC*), CEntrance BlueDAC (BT?.?, VelvetSound™ *AK4490 DAC* coupled with *CEntrance AmpExtreme* Class-A Headphone Amplifier) etc.



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.


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## myusernameislove (Jun 30, 2018)

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.


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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## myusernameislove (Jun 30, 2018)

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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## myusernameislove

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.


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## anton79ru

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



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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## myusernameislove (Jun 30, 2018)

You know, it is reencoding, so some information may get lost. All codecs used for BT transfer are lossy. Ldac even adapts on three settings you can choose from- quality priority, connection stability priority, .... It even analyzes the song in advance. It encodes frequencies that are captured (in already lossy manner of original digital file) in a way that it guesses is most optimal for currently choosed priority mode. In my opinion it may cut something from the original mp3, even if it fits its kbps, simply because it is reencoding. But maybe they implemented mechanisms, that checks metadata, and keeps all information if it identifies, that it fits in. Maybe they just rearrange those ones and zeros.


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## myusernameislove (Jun 30, 2018)

Second paragraph - correct. Best sollution soon may be: Android 8 Oreo phone - ldac - Shanling M0 - Shanling L2 OTG cable - Chord Mojo. Now it does not work, but Shanling promised, that they may implement via future firmware concurrent use of ldac receiver and USB OTG (now you can use either LDAC or USB out). But people say M0´s sound is already very good. And some reports say, that Chord Mojo sounds worse via USb OTG of M0 then if it is connected via USB to PC or to other DAPs via optical cable. Not sure why.


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## anton79ru

myusernameislove said:


> In my opinion it may cut something from the original mp3, even if it fits its kbps, simply because it is reencoding.



Alright, thank you so much for your input, because it really put me on the right track. I ended up getting a FiiO BTR1 to start with. When I was talking about sound getting "better" or "worse", of course, I was not talking about any absolute categories, because I'm positive that there's no such thing. I just wanted to make sure that sound quality would not get audibly degraded in my situation, which is 320 kbps in Etymotic ER4-XR connected either to my Vivo Xplay6 with its dedicated DAC or to a Bluetooth device (also with a dedicated DAC) that receives aptX (regular, not HD) stream. Now I can honestly say that I failed to spot any clearly discernable difference in both presence of very minor noises (that are the first to be eliminated if there's more compression) and stage depth on rather peculiar tracks. That's good news, because, although I'm nearing 40s, my analytical hearing skills can hopefully still be considered above average.


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## myusernameislove (Jul 3, 2018)

Just keep in mind, that I am no expert in this topic. I migth be wrong. Only the engineers who implement such things mith be sure, or maybe someone working in the industry may ask.

One more thing to mention - I have read somewhere, that same chip implementzed in two different DAPs or Phones resulted in two different sounds. My guess is, that manufacturers may parametrize or modify the software, that goes with the chip, or they can tune somehow the sound to get the sound they wish to get. Or they just may keep it in factory settings. They may also use different quality components - board, cabling, connectors, shielding etc. Therefore, you never know how it will sound until bunch of reviews confirm the sound character and weaknesses. If you are interested in such things, try to read through or ask for explanation in Radsone thread. That PR guy seem friendly and he knows what they were doing, he shared few information about the challenges they faced when they were implementing their Aptx HD receiver.


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## radekhulan

Can Ampio P1 VS-1480 work as USB DAC for Windows 10 PC, transmitting LDAC-enabled output to headphones?


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## mikescchen (Sep 26, 2018)

radekhulan said:


> Can Ampio P1 VS-1480 work as USB DAC for Windows 10 PC, transmitting LDAC-enabled output to headphones?


No.
Someone asked this on their FB page and Ampio replies as "The DAC/AMP can only works as a receiver, not a transmitter".
Although I can relate to your need of USB LDAC transmitter; it would be good to see such products, but there are none AFAIK.


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## BigZ12

Sorry, wrong forum


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