Best DAC for my situation...Read on!

Dave
You are exactly right and that would be the plan. Fortunately the C48 has 2 pairs of xlr inputs so I can compare say the oppo dac signal to the c48 and the "whatever" dac signal to the c48 both via xlr.
And the same with the vault, compare single ended direct from the vault to the c48 and same with the "whatever" dac.
Then I can remove the c48 and try the " whatever" dac direct into my BAT.
I am blessed in that 2k is not a huge outlay at my stage of life and the mytek and benchmark have a 30 day free trial.
Plenty enough for me to a lot of serious comparisons.
Tbh it will take something special to make me part with the c48

Of course Dave, I have not totally ruled out replacing the OPPO with a modwright OPPO yet.
However that only has an effect on Redbook CD replay.
Moving to a better DAC should improve CD replay, my ripped collection and Tidal replay so in theory I should get a broader music improvement on spending money on a better DAC.
Mind it was a lot easier years ago when I was much poorer....lol.
That made choices easy.....if it wasn't broke then don't fix it!

uber,

Sounds good. Up to recently, I recall that you were set on a one-box solution?

Since you brought an external DAC into the fold of consideration, I will give you my 2 cents. Having a MW SACD player and a pretty good DAC (Exogal Comet Plus)/Aurender N100H music server combo.

I have fallen hopelessly addicted to the Aurender/Comet combo because streaming music from Tidal is so easy and the sound is pretty good. Also listening to hi-rez downloads from HDtracks, etc. ups the ante to excellent sound quality. I mean EXCELLENT sound quality.

My MW5400ES still sounds better for critical listening, once the right tubes and umbilical/power cords are in place. Image palpability and soundstage size, depth, and layering are in another league. The intoxicating wetness and buttery even-order harmonics/richness of the tube sound can only be produced by tubes, simple as that. Friggin’ incredible dynamics and bass power/slam. Bye-bye grain and edginess. Music.

My MW player only plays CD and SACD. Speaking of that, I was confused by your comment above, "However that only has an effect on Redbook CD playback." ??? Anything you play through your Oppo (CD, SACD, other digital input) and output from its analog outputs will benefit equally from the Modwright power supply, analog section, and tube output section.

Bottom line: If you are planning to do a lot of streaming or need multiple digital inputs for using other sources, Keep your Oppo for other duties and invest the money in an Aurender/DAC-of-your choice combo. Way excellent streaming with the Aurender. So easy to build custom playlists.

If you do not plan to predominately listen via Tidal (I think the Oppo can do streaming via its USB input??), the Modwright mod to your Oppo is the way to go for ultimate digital sound quality IMO unless you get into the $$$ DACs.

Dave

The C48 preamp is around 100dB S/N. I think you will find the Mytek is closer to 120 dB. This is probably due to the very quiet switched Mode power supply versus the Mcintosh traditional linear one.

So it is possible that the C48 would dumb down the Mytek performance if it were in the audio chain. It is entirely possible that performance of many of the Class A or Class A+ DACs are being compromised by typical preamp performance...

The traditional purpose of a pre amplifier was to bring the different output levels of analogue sources to the same level (and add the massive RIAA equalization required by the phono input), to allow you to switch between these sources, to use tone and balance controls, and to control volume.
However, these days you do not necessarily need them anymore. Typical input sensitivity of a hifi power amplifier is now 2V, and typical cd red book standard output of a digital source is also 2V.
So what does one still need? Apart from tone and balance controls which you could also and better do with a mini DSP, you only need a volume control and a switch between inputs.
In a very basic system such as the system in my study, with just a computer plus ODAC usb DAC as a source, all I needed with my QUAD 405-2 power amplifier was a volume control like the Emotiva Control Freak.
With more digital sources like a basic streamer, a disc player, a tv, and perhaps a computer, one would need a DAC with multiple inputs and preferably a volume control. Examples of such units would be the Marantz HD DAC1, the Pioneer U-05, or various Benchmark DACs. Such DACs are in effect the modern incarnation of the traditional pre amplifier. Inserting a traditional pre amp after such DACs just adds distortion, noise etc. Pre amplifiers can only degrade the sound. And they are a waste of money.