Streaming, Getting the Signal, Then What?

Apologies @veemike  but some people seem to know how to quote and I can't figure it out... extract of your opening post follows:

"My PS Audio AirLens into a PS Audio DirectStream DAC MK1 gets its signal from a Netgear Nighthawk CAX80 modem/router purchased in Jan. '22.  I know I get a signal. I hear music play. Is this Netgear product better than the freebie that the ISP provider installs?  I think so. But following discussion FORUM I tend to think I may be able to do better, maybe?

So chime please as to what perhaps I should considered considering my AirLense & MK1 DAC. PLEASE, do not tell me why what I have could be so much better if.... This post presumes I have the equipment I have. From modem/router to sources is a high end AudioQuest ethernet cable product. That also is out of the equation for whomever wants to opine as to my cable choice.

Recommendations please."

If I read this correctly, not only are you not interested in any suggestions that you might improve your system at or after the AirLens streamer, you are also not interested in any suggestions that you consider replacing your "high end Audioquest ethernet cable product". You are therefore seeking only recommendations for a modem/router which might outperform the Nighthawk: is this correct?

If so, then you are pretty good as you are, as the only option you have is to replace the Nighthawk with a lower noise modem/router or to use a lower noise power supply on it or to do something just before your AirLens (see below).

The internet just works, digitally, and the only thing we need to worry about in the pre-streamer domain is noise. Ethernet is based on asynchronous packets of data with error checking so concerns like jitter are nonsense from a sound quality perspective.

However, even if we limit ourselves to commenting on your pre-streamer setup, there are things which you can explore and they focus on RFI noise which ultimately, via your streamer, can reach the analog(ue) parts of your DAC.

You don't say what your "high end" Audioquest ethernet cable is but I bet it's shielded and I bet the shield is grounded at both ends (if you have a multimeter or an ethernet cable tester you can easily test this). A shield grounded at both plugs will act as a conductor (the best conductors make the best shields after all, hence the prevalence of copper shields) and any noise picked up by or generated at the upstream component will reach the downstream component. The audible impact of this obviously varies from system to system as some domestic settings are noisier than others.

A switch installed just before your AirLens would substantially break the noise chain. I'd start with a cheap one as an experiment. A switch here is absolutely NOT here as a port replicator; as audiophiles, we seek to exploit a side effect of how switches work which is that they forward the digital data packets from one port to another but, to a greater or lesser extent, they don't onward transmit the RFI noise.

If you do decide to experiment, buy something like a Zyxel GS108B and position it just before your streamer. Plug the high end Audioquest into this but, crucially, from the switch to the streamer either use a short (ideally 0.5m) unshielded Cat 6 cable or a shielded cable known not to have the shield grounded at both ends (like the Melco C100). Do not use a Cat 8 or most audio-specific network cables here as the shield will be grounded at both ends and the RFI noise stopped by the switch will simply travel down the shield from one plug to the other.

Buying and installing a cheap switch like the Zyxel and a 0.5m Cat 6 (or even 1m Melco C100) is a cheap experiment.

As a matter of interest, please tell me/us how long your Audioquest ethernet cable is and what model it is. This may or may not make a difference. Thank you

Veemeke, You haven't stated what you don't like about the sound of your system. What do you feel you're missing? I'm struggling to understand what are you trying to achieve. Personally I don't believe that investing money in network/router will make much if any audible difference. Netgear is reliable router. Are you streaming music from local library or some streaming service or both? If both do you hear difference in sound and is it coming from local library or streaming service?

@veemike 

Have you tried a filter? One thinks they have no grain in their streaming, until they try something that removes more noise and grain and then they realize they actually did. 

I use an etheregen and it works. Money back guarantee- Alex (Uptone) has sold over 3,000 of these and had about 5 returns which says something. 

The newer one on the block is the smoothlan, also a money back guarantee. I haven't tried it yet, but for under $300 it is a no-brainer. 

check out this thread: some including the OP use both the etheregen and the smoothlan and claim improvements. 

If you have a larger budget for a switch/ filtering this may be the best option: Tempus I have read good things about it- feel free to browse user's reviews of it. 

*you know what? I just re-read my comments above regarding the smoothlan being a no-brainer, and I am going to put my money where my mouth is - just ordered one- I'll post in the above thread my impressions of it. 

Mclinnguy is right Etheregen is great. Audio became a little quieter.  It immediately improved detail in LED TV picture too. 

The newer one on the block is the smoothlan, also a money back guarantee. I haven't tried it yet, but for under $300 it is a no-brainer. 

Thanks tshark, mclinnguy and nigeltheflash. This is exactly what my OP requested; working with what I already have massaging my source/stream into my AirLense.