He can try a Wiim Pro Plus streamer and DAC for $200 or upgrade a bit and try an Eversolo DMP-A6 streamer and DAC.
Please be gentle with me! 🙏
I am a vinyl diehard and know very little of the streaming world.
My son has just bought his 1st amp and speakers a Leak 230 integrated and some JBL 4312G speakers and is currently streaming his music using an Android phone via the USB C on his phone into the USB B input on the amp, using the built in DAC on the amp. So the question is would something like a Bluesound Node N130 as a straight streamer be an audible improvement to his phone?