It is my experience, regardless of the source, a decent output stage and analog volume suits me the best. This prevents any issues with the loading on the amp input stage or with the sometimes poor streamer or DAC output stage drive capability.
I have two that are so transparent as to be non-existent. They do NOT alter the sound by providing warmth, additional "musical harmonics" etc. JDS Atom+ and a Schiit Asgard. Alas, neither has a remote control so I will be buying a Schiit Sega for my main system as none of my DACs have remote volume. I have owned many preamps, from Hafler, to Nakamichi ,to DIY active, passive, and tube. None can beat the ones I mentioned. (The Nak Pa7 was sweet but probably placebo)
Now, IF your streamer has sufficient output drive, IF it implements decent volume control, IF the DAC is decent (internal, no it is probably not) IF it has remote or headphones amp and you want it, then adding another box does nothing for you. Spend the money where it counts: Speakers, DAC, Amp in that order. Yea, I have been amazed how different DACs sound. But some of that may have to do with JRiver or other streamer settings. It would be great if I can change a setting and not put out 2 grand on a Qutest :) For home audio where cables are less than a meter, I consider balanced connections to be worthless and if you understand electronics, you will understand most have WORSE CMCR than just an se connection. Read the papers from Jensen transformers. Many "balanced" connections just add additional input and output devices that are not well matched enough for the "magic" advantages. Studios with 100 foot runs are another story.
A few amps, like the March/Purify are actually true balanced and maybe a slight advantage in a balanced preamp if it is good enough. Having built balanced buffers, FET, OP-Amp and even THAT chips, it is very hard and expensive. An inch of trace matters. Proximity to the bypass caps matters. Hard.
Now, some try to use a preamp distortion to mask source or other induced distortions. Tube buffers specifically. It is adding distortions and masking, but if it sounds better to you, by all means! No one here can tell you what you hear or you what you like. Listen for yourself. The only wrong answer is to rely on you-tube salesmanship. In truth, an NE5558 OP-Amp, well implemented which is sadly too rare, is better than anything else in your chain, so don't be fooled by the slick pages. If you looked under the covers in a studio, you may find your perfect streaming file went through hundreds of them already. If the music is as old as I listen to, probably far worse.
