Taemero

Tidal if using MQA is a scam, its not lossless audio.  That said, HD audio in general is a scam.  The only time it sounds better than CD audio is if it uses a better master or your DAC handles HD audio better.  Its not the fact its HD that makes it sound better.
 
I've never sen any speakers/headphones rated to reproduce that extra range outside of human hearing that is claimed to "make it sound more natural" anyway.

I use a relatively simple set of Philips open back headphones but adding again a simple and cheap sound blaster x6 has turned the sound into something awesome at low cost.
Games I hear footsteps in the correct location etc but music jumped in level to a degree that even my old MP3 of CDs ripped way back in the 90's from bands as Steel Pulse Jimi Hendrix and even my love of Betthovens 7th  sounded like I had been missing out on things for over 20 years.
I am no audiophile but even this cheap little doodad made my listening experience so much better. It is very much an entry level item but I have been using it for around 4 years now and still have felt no reason to upgrade to something better.
 

I am absolutely not an expert on Audio so I am not going to pretend I know enough about different types of DACs etc.  I personally use the Hegel HD12 with a Yamaha s-701 Amplifier and some old Beyerdynamic DT770 headphones and I am happy with how they sound, but this is obviously quite cheap stuff compared to proper equipment. I also have two JBL Studio 190 speakers, I do want to upgrade to PSB imagine x2t soon.  You can get specific DAC's for phones too but you would need to do some youtube research on to what is best there.

You generally need a compatible CPU to update the BIOS. Some motherboards have a dedicated button that allows you to update the BIOS without a CPU installed using a specifically formatted flash drive. Your motherboard, unfotunately, does not. 
 
If you bought it in a store, take it back and ask if they'll flash it for you. Otherwise you have three options. Try your luck with another board, get a board that supports BIOS flashback (off a USB with no CPU installed), or return your CPU to buy a Ryzen 7 3700x instead. 
 
Some motherboards will say 'Ryzen 5000 ready on the box'. That means they already have an updated BIOS from the factory. Get one of those? 

Depending on what is doing the scaling, upscaling can make content look better.
 
As for downsampling. running  a game at 4k on a 1080p display does improve fidelity greatly.
 
As for Youtube, youtube compression at 4k runs at a higher bitrate than at 1080p, so u can still see an improvement in quality. I always watch youtube in 4k if there is the option.
 
As for monitor choice, ull find the best monitors tend to be 1440p and 4k nowadays, so i'd look into getting a high refresh 1440p display. See the pinned thread to find out how best to find and choose a monitor.

1080p is 4 times smaller than 4k, so if upscaled 1 individual pixel of 1080p will reside in 4 4k pixels.
If you can actually see the pixels (like in a large tv) it maybe disturbing, but since a monitor is smaller, you can't see it.
Playing 1080p files in 4k tv, you will definitely notice the difference.
 

It's a render. Similar board would be the Satisfaction 75.

Only Thunderbolt docks support >1080p. Dell Thunderbolt docks have one type C port on the thunderbolt module that supports a monitor
 
https://www.delltechnologies.com/resources/en-us/asset/data-sheets/products/electronics-accessories/dell_thunderbolt_dock_wd19tb_spec_sheet.pdf
 
 
The docks only support 60hz, however that's reading too much into it. What the docks support is a fixed resolution bandwidth. So if you have two 4K monitors at 60hz, you can't run them at 120hz, but you might be able to run one at 120hz. You might not be able to if the dock's firmware doesn't support it though, as the dock itself is it's own MST displayport hub. So even though you have 4 outputs on it, collectively you can only drive 3 FHD monitors, 2 4K monitors or 1 5K monitor. You can't use all the ports.
 
So I wouldn't make a purchase decision based on this assumption. The alternative are Displaylink docks, which are software GPU's and don't even try gaming on them, they suck.

before buying additional hardware to compensate for poor audio quality , try to mess around with in your audio setting page (headphone power, eq, something like that?  or Download an alternate audio driver.

I have the sony WF-1000XM3 and I can agree that they sound better with my Iphone SE 2020 then my PC, not 100% sure why but i would guess that the iphone just has better compatibility with it.

Oh, they're bluetooth? Your iPhone may support a higher bluetooth rev. than your laptop, and use a better codec. Windows is known to have spotty support for bluetooth audio, and when it does uses pretty crap codecs. 

2 things, equalizer settings and/or codec. The headphones support the AAC codec which is used for Apple products and has a higher quality than SBC, which is probably what your PC supports. The more likely reason though is the equalizer settings, whether the headphones one or the Spotify one. If you set a customer equalizer for the headphones in the Sony app, the settings will revert back to the factory settings when the headphones change codecs (such as going from AAC with the iPhone to SBC for the PC). The equalizer for Spotify on your phone might be more preferential for you than the one on the PC. I would suggest playing around with the equalizer to see what you like. 

The included DAC (the adapter dongle) with the iPhone is actually pretty decent. Apple has always made an effort with their sound hardware, as it's kind of their forte. I still use my 15 year old iPod Mini (with a CF card, batt upgrade, and rockbox) because the audio hardware built into it is pretty solid. 
Dell is not known for their audio hardware and likely threw the cheapest audio hardware they could find into the XPS, to focus the budget elsewhere (excellent screen, specs, chassis, etc.). There's also going to be more electrical interference with the audio hardware inside your laptop vs. the external DAC on an iPhone. 
If this is really a concern to you, you could invest in an external USB DAC for your PC audio needs. 

Yeah, rtx 3070 will fit great in this build.

Build looks ok. Will run most of the games just fine. 
But you have chosen overpriced components when you can spend quite less for similar performance.
Also rx6800 is released for $579, so how in the Neptune's moon are you getting it for $499??
 
See, this build looks much more balanced...
PCPartPicker Part List
 
CPU: AMD Ryzen 5 5600X 3.7 GHz 6-Core Processor ($299.00) 
Motherboard: Asus TUF GAMING X570-PLUS (WI-FI) ATX AM4 Motherboard ($189.99 @ B&H) 
Memory: G.Skill Ripjaws V 32 GB (2 x 16 GB) DDR4-3600 CL16 Memory ($139.99 @ Newegg) 
Storage: Silicon Power A80 1 TB M.2-2280 NVME Solid State Drive ($114.99 @ Amazon) 
Video Card: Gigabyte Radeon RX 6800 16 GB Video Card ($579.00) 
Case: Fractal Design Meshify C ATX Mid Tower Case ($95.99 @ B&H) 
Power Supply: be quiet! Pure Power 11 600 W 80+ Gold Certified ATX Power Supply ($79.90 @ B&H) 
Total: $1498.86
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2020-11-18 23:18 EST-0500

IMO the 5600x and 5800x are not that good of a deal.  If you can't afford a 5900x I'd stick with the 3700 they will eventually release a 5700x probably within 4 months.

Look at the performance of the 3600... It can most definitely handle multiple applications at once quite easily, and the render times in productivity aren't that low. Due to the combination of IPC and clock speed advantages in the 5000 series, the 5600x should have similar render performance to a 3700x.

For editing in this resolution, you won't have any problem.
For gaming at this resolution, the cpu won't be a huge burden, the difference will be minimal.

i'd get a 5600x over a 3700x for gaming, but it depends on the price you can get a 3700x for.

I’ll think you’ll be fine. I run a 3800x at 4.4ghz all core with a rtx 3080 on a 1440p 144hz monitor and haven’t seen a bottleneck issue yet. You being at 4k should put less strain on the cpu also.
What games do you play ? 

Check to see if the service manual for that desktop states the HDMI port is HDMI revision 2.0. If it is and you have a high speed HDMI cable, you should be able to run 4K from that machine no problem. The integrated graphics of the Skylake CPU should support 4K @ 60Hz. 
https://www.intel.ca/content/www/ca/en/support/products/88355/graphics/graphics-for-6th-generation-intel-processors/intel-hd-graphics-520.html.
 
For more details, check out this helpful thread one of our mods has put together. 
 
 

G7 is very good indeed, the specs and details the reviews are very positive, However the curve puts me off. It's even more curver then the others. I wish they made the same monitor that wasn't curved 

One thing that LG has over any other display (that i know of) is combination of fast IPS panel with hardware calibration capability.
If this display has good uniformity and well controlled IPS glow it wold be pretty much the best choice for my usecase (games+photo editing).
 
PS. why 4K on 27"?
For my eyes 1440p is the sweet spot.

Some reviews are out, and Hardware Unboxed (a pretty respected channel) has basically said this is probably one of the top gaming monitors on the market.  It's almost TN level fast with all the VA benefits of wide colour gamut and deep blacks.  One thing they really don't like is the curve.  Some like it some don't, so that has to be seen in person.

If you really need the storage space a 1TB SSD and a 2TB HDD will serve you well. In that case i'd go for the ADATA XPG SX6000 Pro and the WD Blue combo.
 
Keep me posted about your final decisions