I want to replace the router/modem Comcast with a high quality for streaming

I bought the motorola 8702 which has docsis 3.1 it’s faster has a bigger buffer, 

what’s very important is that junk $5 wall wart ,you need a linear power supply 

I bought on Audiogon the Linear Tube Audio LPS and its excellent much cleaner sounding and much more musical with all the noise removed.

most modern rough terms are around 4 amp , this LPS can go as high as 8 amp 

and comes with a excellent DC cable going to the router most charge $150,and 

buy a decent power cord like the Pangea  sig mk2 awg14

  for $700 it beats anything under $1200

and also gives a better picture too to the tv Roku  which I like better with voice commands , Qobuz sounds much better .

and buy a quality Ethernet hub and cables 

@fastfreight

WOW! I didn’t realize that you’re using Switch X in series with Gold and Muon Pro. When my Apple routers started to cause dropouts, I went with 50FT LinkUp CAT8 22AWG LAN between my Comcast/Infinity modem and Gold switch. No issues since this transition, even when I’m streaming DSD files that requires very stable network. The direct hard wired connection also ensures zero compromises and less clutter in my space. I also upgraded my network speed to 1Gb/s. 

Someone else mentioned the Netgear NightHawk modem and I second that.  I have used one for a number of years with no issue. It is Comcast compatible. Model CM2000.  The router and all network components are Synology. 
 

I also use the iFi LAN I Silencer product in various spots on the network and do think it made a positive impact on music streaming/playback. You might even give this a try before you upgrade equipment. 
https://ifi-audio.com/products/lan-isilencer/

@nyonalake 

I feel your pain, as a Comcast customer for the last 7-8 years I tried to go the route of buying my own cable modem to save some money on rental fees.  When I decided to buy a modem instead of renting I tried the cheap way first and got a Comcast compatible modem for around 80 bucks, that was a total fiasco with all kinds of connection problems.  Then I got the bright idea to go with a top of the line Motorola that was the fastest thing I could find, the cost was somewhere between 5 to 6 hundred bucks at the time, so certainly not just any old modem.  The problem was, from the start I had connection issues with the new modem, when I had a good connection it was blazing fast, so I just dealt with those issues for around 3 to 4 years.  I had to constantly reboot all the devices connected in my home to make everything work which was a pain but I was still saving some money so I kept rebooting everything.

I finally got fed up with all the connection problems and the constant rebooting, so I went to our local Comcast/Xfinity store and picked up their latest modem.  Since hooking the new Xfinity modem up to run my internet my connections issues are gone, and the new Xfinity modem is faster than the Motorola was.

  So, here is my opinion on running a modem while on Comcast/Xfinity service that you are not paying them to rent.....they intentionally cause the connection issues with modems that you don't rent from them just so you will finally get tired of it and do exactly what I did-rent from them.  I can't prove any of that so of course this is only my opinion, but since I am renting from them again all my connection issues have pretty much disappeared.  Hope this help, good luck if you do decide to buy your own modem.

OK.  I just pulled the trigger on a Netgear Nighthawk.  Docsis 3.1 and 2 gigabyte internet ports.  I see some modems that can handle higher speeds up to 2.5GB but in my neighborhood service seems to max at 350MB/sec.  The tech mentioned that they would have to pull fiber before they can go faster than that.  It is difficult to upgrade in my neighborhood as everything is underground. Looks much better but not easy to modify.

One thing that I did make sure my new modem has is 2 ports.  The Spectrum (Comcast) modem only has one port so my cable to my audio system has to plug into my router.  Now the audio system will plug directly into the modem.

It will be here this afternoon.  Wish me luck.

Jerry