Definitely some cool stuff! I know very little about audio equipment, but my Cousin is a bit of an audiophile and I get to use a lot of his hand-me-downs that he doesn't have room for! I have quite a few pairs of higher power QSC PA type amps that work pretty good at filling my 30,000 sq foot shop/echo chamber, and several Emotiva pieces to feed them to 4 Carvin PM153s. (moves a lot of air, makes a lot of noise...he hates it, LOL!) He did give me a couple of modified ADCOM 5500 mono-blocks and some like new Klipsch bookshelf speakers for one of my TV setups, Emotiva PT100 at the controls there. And don't ask me what was modified in those ADCOMs - he told me, but it went right over my head, LOL!It's a Qinpu A3 (8.5Wx2) hybrid that I use with a pair of Dayton B652 bookshelf here in the vape shop. The stock Chinese 6N3 tubes were quickly replaced with a pair of JAN GE 5670W (I removed the standoff between the plastic tube guards as the 5670 are much shorter than the 6N3), but it will take 2C51 and Western Electric 396A if you can find a reasonably priced pair.
Source is the Line Out from an Amazon Echo (3rd Gen) streaming Spotify.
I've never tried the line out with any of my headphones as I have a Little Dot MK IV OTL headphone amp for my high impedance cans. I do have a pair of 50 ohm Fostex T50RP MK2 Planar that would probably work very nicely from the speaker taps. I'll have to try it one of these days, that might save me from ordering in an Emotiv BasX A-100 amp for those. A pair of jumpers inside the A-100 can bring the speaker output power directly to the headphone jack for seriously hard to drive headphones like the HiFiMan HE6 etc.
I do love the euphonic sound from tube gear.![]()
He's talked about tube stuff before and I know he's done a lot of research, but I don't think he's ventured in that direction yet.