Hi,
some good suggestions above.
I have had the MFM6X DAC since September. It replaced a broken TEAC ud701n, which sounded wonderful until it didn't! Fed initially from 2021 Node, Qobuz, Radio Paradise FLac and MQA streams. Although very acceptable sq, the arrival of an Innuos Pulse has elevated sq to another level. Connected with an AQ carbon usb, I use the filter 8 which upsamples to 352.8/384 and the difference between red book and high res is now negligible in many cases. I have a few MQA CDs which unfold to 352.8 and are excellent- close to SACD. No HF noise or sign of lossy to my ears. Regular CDs benefit from the upsampling. The Pulse will output MQA via usb, should that be of interest. There are some MQA tracks on Qobuz to test it and works seamlessly. At just over £2k, the M6x is good value to my ears, but haven't heard the competition - after my TEAC experience, will not buy Chinese again. The pulse would stretch the budget, but the pulse mini might suit. The Innuos Sense app is just as good as BluOS, perhaps better and plays RP natively with simply superb sq to my ears. MF do a streamer for similar money.
the M6X and Pulse are my end game front end and don't doubt there are many fine sounding alternatives, but not many are built in Europe with a good reputation for support and reliability. Well worth an audition, imho.
edit to add: just re read your post and agree female vocals sort the wheat from the chaff. Joni Mitchell hi res, Agnes Obel, Sophie Zelmani, Patti Griffin and Natalie Marchant all sounding lovely to my ears. Rainy Night House, live by JM with its delicate HF percussion wonderful.
Sense app screenshot.