AVR as a streamer + external amp. Why sounds worse than amp itself?

[Romish]

Hello all.

I am not very advanced in HiFi matter. I'm rather enthusiast who is interested in tech staff that could help me to build good stereo system without heavy investments. I've been using Pioneer VSX-LX505 for about 1.5 year by now as Home theater system for movies and PS5 sometimes. The acoustics set was JBL Loft (JBL Loft 50 flowstanders as front pair). It was quite enough for movies and gaming. I listed to music from time to time in stereo with Pure Direct preset. It was not horrible, but I was quite sure that there was some other devices out there (amplifiers, streamers, DACs) that could do way more in the field of HiFi stereo sound. So I started from the cheapest point (that I could figure out at the moment), I decided to buy external amp. It would not introduce a lot of additional Hardware but could considerably improve sound quality. Based on the ASR review of Pioneer VSX-LX505 I established that amplification part of Pioneer AVR is not that good while DAC section is OK. Luckily I found Audiolab 9000A on sale (not only amplifier, but Integrated one with quite nice DAC inside) for less than 1000$ and bought it. I connected it with Pioneer through AVRs Pre-amp RCA outputs. The cable I used - Telecom TAV7158M (not specialised HiFi, but shielded and made of copper). Did it make change in sound? Yes it did. Did it impress me? Not that much.

*I think this is the right time to say about music source. I use Airpay 2 from iPhone streming service application from "Music provider" popular in my country. I have good subscription so "Outstanding sound quality" switcher is available and switched on.*

This is when I thought that the limit of my low-end accoustic is reached. There were no regrets as I was quite decisive on building good sounding system and the next step was to visit HiFi store and listen to 5-10 Stereo setups with "the most reviewed and renowned" loudspeakers today (in budget). But before that I decided to try another sources for my new amp. The easiest way was to hook up my Windows Notebook through USB A - USB B cable directly to the Amp's DAC. I bought Ugreen US135 cable. It looks good, costs less that 5$ and honestly says "USB-A to USB-B Printer cable" on the box.

*The source was Streaming app from the same "Music provider" for Windows.* Yes, I know that qulity can be different from track to track, but I use the same Favorites list.

Guys... this was a considerable step forwad in sound quality which me and my wife could unmistakably hear. Even with old acoustics. This is where I want to ask you, dear experts:
1) Why does the variant "iPhone Streaming App - Airplay2 - Pioneer AVR (DAC, Pre-Amp) - 2RCA-2RCA - Audiolab 9000A Amp only - Acoustics" sounds worse than "Windows Streaming App - Notebook USB-A - Audiolab 9000A USB-B - Audiolab internal DAC, Pre-Amp, Amp - Acoustics"?
This is not very convenient to move my laptop to another room and connect to amplifier to listen to the music. It seems like the Streamer (or maybe just 'Transport') would be the easiest solution to complete setup for streming as only source. But, as I don't have any experience in testing Optical, Digital RCA connection I got another question (or two).
2) Is there any difference between feeding Integrated Amplifier DAC via USB, Optical or Digital RCA input? Music through USB specs (at least for Audiolab 9000A) looks more advanced but does it really matter?
3) What does it mean in 9000A's user manual: "Inputs: 1 x PC USB (USB B - Windows / mac OS only)". Can Audiolab 9000A amplifier receive data via usb from Windows and Mac PC only? Streamers are not supported?
4) (Kinda depends on question 2 and 3) do I have to concentrate on searching Streamer (Transport) with 'USB output' support in spec?
5) Is it possible that with Streamer (Transport) sound quality will be rather similar to Pioneer AVR setup version considering I want to use Airplay 2 from my IPhone to Streamer (as one, but most important use case)? (My intention is bypass streamer internal DAC (if any), but if I finally buy the one with even better DAC than inside 9000A, I won't be able to help myself and I will defenitely try using Streamer's DAC+Preamp).

Just for info. I went through listening session in HiFi store. Luckily they could connect all the contenders to the same Audiolab 9000A. I finally bought Sonus Faber Lumina 3 florstanders.

And sorry for my English, I am not a native speaker.

 

[Miniyouuuu]

Low-medium tier AVRs cannot compete to an Audiolab 9000.

Too many functions to be developed by one only equipment: streamer, DAC , amplification, multiple inputs, multiple channels at less than 1500$. Don’t expect to receive the same as a 2200$ integrated with a good DAC.

Preamps are more important than what we think. If you use AVR as preamp sound will be different from Audiolab preamplification.

If you don’t need more than 2 channels buy a nice preamp and DAC with HDMI and continue with the Audiolab. Eversolo DMP-A6 master edition is a nice match.

 

[Romish]

Low-medium tier AVRs cannot compete to an Audiolab 9000.

Too many functions to be developed by one only equipment: streamer, DAC , amplification, multiple inputs, multiple channels at less than 1500$. Don’t expect to receive the same as a 2200$ integrated with a good DAC.

Preamps are more important than what we think. If you use AVR as preamp sound will be different from Audiolab preamplification.

If you don’t need more than 2 channels buy a nice preamp and DAC with HDMI and continue with the Audiolab. Eversolo DMP-A6 master edition is a nice match.

Thanks for the anwer. I didn't quite get your thought concerning HDMI though... It is not used now. And it will not be used in the future. Audiolab 9000A does not have HDMI at all.
It just dawned on me that maybe the problem is in the Airplay 2. Before now I didn't realize that it can degrade initial sound quality. And quick research proves it actually does.
My initial intention was to proceed with using iPhone streaming app of music provider to quickly search and change tracks, explore my Favorites, etc.
You are right about Eversolo or similar streamer. Seems like the only way for me to exclude Airplay 2 and continue using mobile app is to buy a streamer running Android. In this case I will be able to install Provider app directly on the Streamer. But ... this way (just checked) I will not get fully functional Provider app. I will be able to switch track and that's all.(
Eversolo is not that cheap if we are talking about streaming only. And it is not that compact too... But probably there are no so many alternatives. I have to do another research on that).

 

[Miniyouuuu]

There are multiple choices:
-add a streamer only. Wiim pro/wiim ultra or even cheaper alternatives. I have the AppleTV connected to a TV and an audio extractor. Here you’d have high res audio without airplay issues. And nice album covers in your tv.
-add a streamer with DAC. In this case you should try to improve the internal DAC from the Audiolab. There you have to spend more.