Help! Receiver or preamp? Im overwhelmed...

I need some help. Been gone for years and much has changed and Im just overwhelmed with the years of info on the forums. I dont want to make a foolish decision and would so appreciate the communities gracious knowledge and assistance.

Im 75% music and 25% HT. 

Paradigm Studio 100 v4 mains Paradigm CC690 center 
Paradigm V2monitor surrounds
SVS PB13 Ultra Sub
Emotiva XPA 5 amp (200x5)
Keeping all the above

The old 5 channel Rotel HT1055 receiver (no HDMI) needs to upgrade even though I love the sound! Im fine with 5.1 and not interested in Atmos. Im also fine with a used item. What do you reccomend for some killer sound and updated HDMI?

What's your budget?   This will probably dictate what we recommend.  Such as under $1000.  $1000-3000.  $4,000 or more. lol.
Post removed 
The OP asked for help on the receiver/preamp side of things, so I don’t think we should be overloading the response ledger with disc player recommendations.  So any, a few observations.

1) Budget is important, as others have noted
2) Latest HDMI?  First of all, that is a moving target, as all of us have to deal with.  It changes frequently.  Otoh, since you are willing to buy used, that can be an advantage.  Many a consumer has moved on from a perfectly good component because the HDMI standard has changed.  If your monitor, disc player, and other sources are happy with an older standard, then you will have quite the market to choose from.
3) Consider Room Correction.  IMO, this is the biggest sonic advance in HT over the past 20 years, particularly if music is the main priority.  For me this narrows the choice down to three companies: Anthem, Yamaha, and NAD.  Anthem and Yamaha use their own proprietary RC, and NAD uses a third party, Dirac.  I haven’t heard a NAD, but I use Dirac from another vendor in my 2 channel system and love it.  I have 2 Anthem 5.1 AVRs (MX 520) both were huge upgrades over the Onkyo and Pioneer ES that preceded them.  I heard the Yamaha demoed at my dealer and it wasn’t as immersive as Anthem but it is very good with dialogue.  Again, your priority is music, so I’d go with Anthem
mahler123:" The OP asked for help on the receiver/preamp side of things, so I don’t think we should be overloading the response ledger with disc player recommendations."

Hello mahler,

     Did you not read my entire post or did you just not understand my proposed solution that goes above and beyond his original question and is likely much easier on his budget, no matter what the OP states it actually is, as well.
     An Oppo, combined with his existing 5 ch amp, would outperform any a/v receiver or preamp/processor that I’m aware of. He also gains an excellent universal audio and video disc player with a built in video processor, if he doesn’t have one already.
     I’ve never had the issue of an outdated HDMI input or output with either the Oppo 105 or 205 and doubt the OP would either.
    The only downsides of using an Oppo 105 or 205 as a preamp/surround sound processor are the following:
1. Atmos is not supported.
2. There is no auto room correction.
3. If vinyl playback is required on the system, a separate 2-ch preamp is needed.
     The OP said he only uses 5.1 surround audio for HT. room correction is seriously overrated and, if proper care is taken in selecting and positioning all speakers and subs in the room, it’s not necessary in my opinion and I’m waiting for the OP to state whether he uses vinyl as a source.

Get an Anthem AVR.

I say this because it's cheaper than their HT processors with 99% of the same parts.  The big difference is the AVR only has RCA outputs.

So, even if you decide to keep using your Emotiva amp, you save around $1k.
Thank you SO very much gentleman! I should also mention I will be keeping the Rotel (Not that it matters). As for the budget, I'm guessing up to $1000 would snag me an excellent unit in the used market? I do not play vinyl so that will not be a concern.

As far as video I'm guessing I want to be able to upgrade to a minimum of 4k handling ability, correct? And honestly, to play music we use either a Playstation 3 and 4 for discs and use it to access the internet for music sites and use the optic connection to the receiver. We even use an old Toshiba HD-XA2 for upconverting old movie content and some audio through it as well as it has a Burr Brown Dac. Use Playstation 3 and 4 for online music, movies, games etc. 

So yes, this boat has oars and we are probably missing out on a lot! For heaven's sake, I'm still using my speakers with one set of cables instead of Bi-wiring. So I need to learn about that too...Shew, work, and family have made me quite illiterate in the HT game, but I'm keeping faith there is potential!    
Would a Marantz SR5014 or SR7012 be a good choice? Or would the audio not be as satisfying as Rotel? What older Anthem unit would be a good choice? I like music to be very dynamic and hard-hitting...

Marantz NR1510 UHD AV Receiver...What about this? Since I have an XPA 5 Amp?

"... What do you recommend for some killer sound..."

I’ll just spit it out and let the chips fly. A two channel system with a good pre-amp and power amp.

Edit: Sorry I didn't know I was in the Home Theater group...but I said it so I wont take it back. Just ignore me. 
I’m thinking pre-amp/processor as well Russ. No worries brother. I’m in desperate need of advice as I’m 200 miles from any pro audio places. Much appreciated!
jsbranham7 - I think you may have mentioned some options that might really work for you.  For starters, that Marantz SR7012 just might do it for you.  We happen to have a den w/ Paradigm Studio 100s up front, Paradigm Studio center & surrounds, and an SVS sub.  We've gone both ways w/ an external amp - B&K or Odyssey.  And right now it's neither of them - we're bi-amp'ing the front channels directly from the 7012.  Got that SR7012 on an absolutely super deal (so that may help a little to make things sound darned decent to one of us).  Anthem is good stuff, too - that's prob. my next choice (but it'll never beat the price for our 7012).  If you can get such a deal or try 'em either could be highly recommended.
With your budget, I would recommend a used Marantz AV processor. I've had one for about 6 years, never had a problem. A used Anthem, a better piece, is over your budget.
I’ve had several Marantz ‘s they held up great I only got rid of them because I decided I want to separates. You can always find a good deal on one used

I noticed you said 75% music 25% HT. I am sort of going through the same thing I have separates Integra 80.3 processor and Sunfire Cinema Grand series II 5 channel amp. Thinking of going back to a new receiver also something in the middle to catch the 25% HT but a looking for a used higher end integrated amp to get the 75% music i am getting more interested in. So some choices.
Nad 758
Denon x4700
MarantzIntegrated amp Music 75%
Audiolab 6000ANad C 338
Cambridge Audio CXA 60

I have a Rotel prepro, and if you like the sound you’re getting now I wouldn’t recommend Marantz, which has a very different sound profile with a softer and less detailed treble but a fuller, richer midrange.  If you’d like to keep the basic sonic traits you have but just improve it across the board I’d go with Anthem.  There’s a used MRX720 on US AudioMart for $1600 (I’d offer $1300 as Anthem just introduced their new models) that would provide better 2-channel performance but also much better multichannel processing and room correction.  It’s a bit over your budget but a nice step up if you can swing it, but if not you can probably get a used MRX520 for around $1000 but I think is a step down in their ARC room correction.  Personally, if I’m you I’d buy the MRX720 as it’ll give you great all-around improvements and I think you’ll be thrilled.  Anyway, FWIW and best of luck. 

You say that an Oppo 205 would do the trick - but can it control volume with the analogue outputs? I ask this because my top end Panasonic 9000 can't - I needed to get a volume control with a remote - so I just caved and bought the best sounding processor I could find used. That was a Classe 800 - it sounds amazing, but can't do 4K - which is why it didn't cost $15K. Compromises, compromises ...
Denon X series, if you already have a five channel amp and want to use that in conjunction of the Denon’s preamp out it’ll work great. Just get an X3700 and be done with it. Best performing processor receiver for the money by far. 
Love my Pioneer SC LX81 but depressed looking at what they're worth now; sounds great with 2 ch and 5.1.

My LG is OLED but pre 4K and still does it for me- still a fantastic easy to watch tellie
The Anthem MX 520 cost me about $1100 when purchased from my dealer.  There may have been a slight price increase in the year since, but it should be close to enough to your budget to justify a little stretch and the advantage of owning a new component.  I greatly prefer Anthem sound without Room Correction to Marantz and Denon.  With ARC, it’s not even close, imo
@mahler123 How would you describe Anthem, vs Marantz and Denon, or Rotel for that matter? 
The Oppo suggestion would be good if they hadn't been out of production for at least two years, with used units going for 2x (or more) of the original purchase price.  The new Anthem multi-channel units look good, although if you're keeping your 5-channel amp not sure why you want a unit with internal amplifiers.
@Fatdaddy I guess because AV processors seem to be over the budget and receivers that have internal amps seem to have a lot going on for a reasonable price. You would think units without amplification would be less than those with...go figure.
You can get a used Marantz AV7702 MkII unit for $1000-1300.  I would recommend them because they have excellent power supplies and are the only processor at this price level that have fully discrete analog output stages.  That being said, they do have soft and rolled off high frequencies.  Excellent impact, but if you are using a warm sounding amp it may become too warm/slow.  The Emotiva XPA-5 is a very fast/bright amp and would not have this problem.

The Anthem is going to have much faster attack and better high frequency response, but it could come across a bit bright, especially with your XPA-5 amp.  I don't know that I would go with a AVR receiver because they typically used a single shared power supply for both preamp and amp sections and they aren't that big of a deal.  The processors generally have much better power supplies and are dedicated to preamp only.

If you want something new, the Outlaw 976 is really the only option within your price range.  It's voiced similar to the Marantz 7702, but it doesn't have as good of a power supply and the user interface is rather cumbersome.  It also doesn't have the discrete analog output stages.  The Marantz is a better product here, but you have to buy it used.  The AV7702 is not going to be more than 3 years old (not really old at all).  The 7702 is also pretty current for HDMI (4K and HDMI 2.0 support).  There's actually a mkII on audiogon now for $1,000 even.

Denon doesn't have a processor, so you'd have to get an AVR receiver.
auxinput, Wow. Thank you for that detailed explanation. And darn it, right when I was thinking of sucking it up and getting the new Anthem MRX 540 at $1600...
I'm a big fan of Yamaha AVRs. I've posted this before that Pioneer home electronics was bought by Onkyo and then Amazon and Best Buy discontinued sales of Onkyo products in 2020. Marantz and Denon were bought by Sound United in 2017. Usually, but not always, when this happens companies are looking to use the names of the companies only and they often look for ways to keep prices the same but use lesser components. Again, this doesn't always happen but it frequently does. I'm not saying it happened in either of these cases, but you can proceed at your own risk. Yamaha on the other hand, continues to make their own AVR equipment and typically has the best reliability ratings of any audio equipment manufacturer. 
Post removed 
@Winnardt, This is a valid point, especially understanding the corporate world. I don't doubt the audio world would be immune either. Actually, as subjective as audio is, it's probably ripe for the corporate picking. Just as an example, I called Marantz to ask a question today, and after receiving the callback, the individual from pre-sales team whom should be armed to the teeth with the knowledge to sell the products had less knowledge and understanding than I... whos been out of the hobby for 10 years, If that tells you anything. 
Some great responses. I’m watching with interest because I am going through pretty much the exact same ordeal but with different equipment.
I’m leaning towards Anthem Pre/Pro to go along with my Aragon amps.
There are some used Anthem products online if you hunt around. A lot of audio dealers sell products on eBay. Now that Anthem brought out new models I’ve been looking for a used AVM 60. The AVM 50’s are nice units also and closer to your price range. I probably wouldn’t go any older than that though.
Good luck!
Compare Anthem with Marantz, et. Al...

for me, room correction is very important.  I am not sure where Marantz, Denon, Rotel are with RC.  I would compare Anthem with Yamaha, and I already stated why I had a preference for Anthem
Hello jsbranham7!  I'm in just your situation, HT and surround sound music, hooray! I recommend the Emotiva MC-700 preamp/control center. It offers first class sound, but fewer decoding choices than a surround sound receiver. A used near top or top of the line Integra receiver can be had for less than $300 (likely $200 or less) and offers ten or more decoding choices (lots of fun) plus radio and the sound is B to B+ (quite good). You can always put it in another room if you upgrade to one of the very pricy Pre-Pros.  Use the "preamp outs" on the Integra receiver. I have three such setups running in my home. The Emotiva MC-700 controls the main system. There are five systems in all, one using the receiver as its maker intended.
As sort of mentioned, I would post this question on a HT forum, not here...this is predominantly a 2 channel forum, although some here still introduce a sub to a 2 channel set up, ugh...🙄
If speakers are not doing it for you in the bass dept, time for a better "pair" of speakers.
Hello, I haven’t experience to advise you, but I have read one interesting article about Preamp vs Receiver – Detailed Comparison.
Marantz is the best sound I’ve ever used.I bought them on eBay a year ago and they are still in perfect condition.
Seems like you like the Rotel sound. With music your main priority, Why spend the money on a video upgrade which may introduce a possible audio downgrade? You can get a 4K 4x1 HDMI switcher for about $300. It will have a 5.1 digital output to connect to the Rotel. Use rest of budget for bi wire or something.
You might find it interesting to disconnect your rears for a bit and use those channels to see how good the studio 100 would sound bi amped 
Come to think of it, you could bi amp the 100s and power rears with the Rotel 
This may not suit your purposes, but I don’t use the video portion of my preamp for purposes of convenience. All HDMI sources are routed directly to my display and I use the Toslink output of the display to forward the sound into my 2.0 setup. You could also use the S/PDIF outs from each video source to the Digital inputs of your Rotel.
I actually found that audio over HDMI sounds a little edgy and fatiguing. When I first heard audio via HDMI, I called up the local HiFi shop and asked their resident audiophiles; they told me they preferred S/PDIF to HDMI for the same reasons.
Since you like the sound from your Rotel and if HDMI switching is necessary, I’d suggest staying with Rotel for a replacement, preferably a preamp, depending on what you are willing to pay. As always, I recommend used gear. These things depreciate faster than a new car, especially when newer features & formats are added.
burndonesinkchair , yes same train of thought as mine. Other ways to get HDMI switching. To be clear to the OP, in my experience using optical out of tv would downmix the audio to 2.0 PCM. TV streaming may still be 5.1, but not external sources. Using an outboard HDMI switch would preserve the 5.1

Post removed 
@oringray — Go away Skippy.  Nobody wants you or your game here — this is not the place.  Shoo!!!