Have a look here: https://www.audiosciencereview.com/forum/index.php?threads/eq-software-for-windows-linux-macos-ios-ipados-and-android.18450/

As bit perfect means no alteration of the number of channels, the samples and the sample rate, it is most of all a impossible question as you can't do EQ without altering the samples. EQ is bit imperfect by design and when done right, sound quality improves compared with a bit perfect stream.

https://rme-audio.de/adi-2-4-pro-se.html

If we assume identical amps, it will be worse! Using 2 amps instead of one will double the power double the distortion double the impedance However, well designed amps have such a low distortion and impedance, this doubling is trivial. In practice the single ended might be substantial worse spec...

There is an exception to this rule. The Pentaconn is TRRRS so 2x2 for the "balanced" connection and a ground. This can be used for TRS connection by using L+, R+ and the Ground.

Wouldn't be surprised if you can install a UPnP compliant media server on it. If your "homeserver" is a NAS e.g. Synology or Qnap, it even comes with one. PS: https://support.plex.tv/articles/200350536-dlna/ says plex support DLNA so you can combine it with a WiiM

Try https://diyaudioheaven.wordpress.com/digital/pc-software/foobar-2000-for-dummies-part-3-new-experimental-sacd-plugin-v-0-9-x/

Don't know if it is still available but Sound Liaison did offer one in 768: https://www.audiosciencereview.com/forum/index.php?threads/finally-music-we-can-buy-in-768-khz-sampling-rates.29544/#post-1033369 If not, you have to settle for 24/352...

Tagging WAV is a known problem. The WAV tagging standard is a bit limited (no album art). Some developers solve this by writing ID3 tags to WAV but that is not a standard. https://www.thewelltemperedcomputer.com/KB/WAV_KB.htm My suggestion would be to convert some files to FLAC. Check the FLACs...

Best is an amp like the A50s. You can choose between high and low gain (less power). The low setting is ideal for IEMs as they are often high sensitivity.

As the N100 is a transport only and delivers USB audio, you might decide to add a DSP module doing the EQ https://www.audiosciencereview.com/forum/index.php?threads/using-orangepi-zero2-as-an-equalizer-between-usb-source-and-usb-dac.53750/#post-1946851

To the best of my knowledge, Tidal Exclusive uses WASAPI in Exclusive mode so it talks straight to the DAC and can do automatic sample rate switching. In fact the whole Win audio is bypassed. Wonder why you use Voicemeeter.

The Jotunheim 2 can be found here: https://www.audiosciencereview.com/forum/index.php?threads/schiit-jotunheim-2-review-dac-headphone-amp.21232/ Wouldn't go for the multibit DAC, way to noisy. It has analog balanced in and outputs at line level and a "balanced" headphone out. Personally I'm not...

The 800s comes with a TRS and a TRRS (Pentagonn). The Pentaconn allows a 2x2 connection. If the amp offers a 4 pin XLR, you can replace the Pentaconn or use an adapter. I had the 800 that comes with a audiophile style cable. Long, heavy, stiff. When it broke I replaced it by a Hart Cable. They...

To be honest, I didn't read your post completely, too long In 2013 I decided to buy a new headphone. I compared the HD600and the HD800 (the star at that time). The 600 sounds good but not as good as the 800. Maybe if I was more familiar with EQ I might have tuned the 600 to sound like the 800...

No. Sources range from 16/44.1 to 24/192 kHz. Modern DACs can play them all. App's often allow you to play them at their native sample rate as well. The difference between streaming audio services is the format they use. This can be lossy compression, CD quality (16/44.1) or Hires, anything...

See a lot of DACs with 24/192 over S/PDIF and 32/ 768 USB. Might it be that 192 and 768 is a properties of the receivers, not to be mistaken for the internal sample rate used by the DAC chip?

WA7 pleases the eye indeed. If this applies to your ears as well is a different story: https://www.audiosciencereview.com/forum/index.php?threads/woo-audio-wa7-wa7tp-dac-and-headphone-amp-review.7028/

Have a look here: https://diyaudioheaven.wordpress.com/headphones/measurements/audeze/lcd-2-classic/ It is probably pretty good in the fundamentals but suppresses the harmonics. I expect it to sound dark. Wouldn't buy a headphone with such a weird frequency response.

Bit weird as to the best of my knowledge, CD player output is standardized at 2V. One expect the amps to cope with this. Any option to reduce the gain on the amps? You might try a passive inline attenuator.

They don't. They have Optical and USB inputs. Might help to specify brand/model. As they have optical and USB inputs, they are powered speakers, speakers with a build-in amp. Hence your Dm41 is of no use as it is intended to drive passive speakers.

Another vote for dBpoweramp. It is fast and stable. Easy to configure. It supports AccurateRip (they invented it) Meta data from GD3, Discogs, SonataDB, Musicbrainz & freedb Can be used as a format converter as well.

Just a wild guess. The moment you make a phone call, BT uses the HSP (Headset profile) instead of A2DP (High quality stereo). HSP not only needs a DAC but a Mic as well. Maybe because of this the USB DAC is not used as it is a DAC only, not a ADC+DAC?

Just to make sure, are you using Apple Music? If not, as the switcher reads the log of Apple Music, it won't work.

LL= Low Latency not to be mistaken for lossless or high bitrate. I wonder if LHDC got any traction outside Huawei You might have a look at LDAC. Don't focus to much on the codec, the DAC and amp in the receiver are important as well.