Good tube amp under $100?

I recently got a pair of HD6XX’s and I use a Fiio Q1 Mk2 to power them. I really like the sound of the fiio but I’ve heard really good things about hd600/650’s with tube amps.

Feb 13, 2019
I'd get into tubes but it confuses the hell out of me. How do you know what tubes to get? what fits?
Feb 11, 2019
The Aune T1 is a sweet sounding DAC/Tube Buffer/SS Amp, and simply needs a good NOS tube to sing. I have upgraded the caps, in the older versions, for more depth & stage, though recently got a used MK3 off the bay, and with a Sylvania NOS tube, it may be on par with the MK2's I have modded. I think Aune may have upgraded more than just the DAC (now DSD1793) in the MK3. When I mod the next MK2 I can compare them side-by-side. In short, this MK3 is a great way to dip into tubes, if you like them,, get your wallet loaded up... Used; try offering $100... or request it here on MD, it will drop again.
Feb 11, 2019
Don't discount something like the Schiit Vali 2. It's actually a pretty phenomenal amp for the price and a good way to get into tubes.
Feb 6, 2019
Most of these are hybrid amps which start with a solid state circuit and just add a tube for looks and possible "tube coloration". The benefit of real all-tube amps is that tubes are way more linear than transistors and require much less corrective circuitry, which will appeal to audio purists. I don't have personal experience with these, but check out APPJ 1502A, Darkvoice 336SE, Little Dot MKii, FX Audio Tube-P1. Or if you're seriously into DIY you can get one of the single ended class A 6N2+6P1 integrated amps, about $140 with shipping from China. If you add a headphone jack you need to make sure to add a parallel 8 ohm 10 watt resistor so that the amp sees the expected load. You'll also need a drill bit suitable for drilling the steel enclosure:

Feb 9, 2019
"...way more linear..." - I like the sound (pun intended) of that. My sole experience of a SET amp was auditioning a w-a-y expensive Cary integrated via its headphone jack. Nice, but there were harmonics surrounding every note like little Christmas bells. I may eventually go with tubes, but with a push-pull design, not single-ended.
Feb 1, 2019 This is a very nice sounding portable tube amp with swappable opamps, also has a balanced headphone output too
Feb 1, 2019
Spend the extra $100 and get a DarkVoice. You won't regret it. I've lao heard good things about Little Dot. You can find the Mkii for around $150. The Mkiii is also around$200. Also, plan on an extra $50-$100 for additional tubes. It's part of the fun. 😈