The Evolution of Smart Home Technology: What’s Next?
Smart home technology has evolved dramatically over the last decade, transforming how we interact with our living spaces. Initially, home automation was seen as a luxury—an area for early adopters. The first wave included simple systems like programmable thermostats and lighting controls. These basic innovations were designed to increase convenience, save energy, and offer greater control over household environments. But today, the landscape of Top Smart Home Devices has expanded far beyond those humble beginnings. The rise of voice-activated assistants such as Amazon’s Alexa, Google Assistant, and Apple’s Siri helped fuel the revolution. These devices became the central hub for an entire ecosystem of interconnected gadgets, enabling homeowners to control everything from lights and thermostats to security systems and home entertainment with simple voice commands. The ease of integration between devices has made smart homes more accessible and user-friendly, marking a...
Feb 11, 2025
I just bought the O2+SDAC for my HD6xx, HD58x, HD600s (the only 3 headphones I own - the former two are new). I opened it 2 days ago. If you buy this T1 amp/DAC, and it is not the sound you are looking for, maybe you'll opt to trade with me. I am open to it. If I had read more beforehand, (and if this deal were available 2 weeks ago) I would have gone with a tube. I think the warmer sound lends itself more to a "set it and forget it" style of code-all-day listening. That's the purpose I bought the HD6xx for, and furthering that end is the purpose I bought the O2 for. IMO, the O2+SDAC _really_ shines with my HD600s, which have a forward, clear, sound that is detailed and in-your-face, demanding attention. From now on I will only use that for special occasions, like the first listen through a new album from a favorite musician. In short, The AMP/DAC combo is more dedicated to detail than mellifluousness. I have a fiio E17 AMP/DAC which doesn't take things as far as the O2, but it does seem to just make everything "prettier" though not necessarily more clear. That is what I want for my HD 6xx, and I think that this tube amp is the better bet for me, having heard the O2.
- turn off the amp - carefully unplug everything (warning: tubes are hot!) - let it cool down for a few minutes (preferably a minimum of 10 min) - take out tubes, careful to not bend any pins or apply too much pressure on the glass - open bottom plate (unscrew both front & rear two bottom screws, and the plate will come out; I let mine open all the time) - if you feel like replacing the opamp, now is the time: take out the opamp you got installed, careful to not bend any pins, and install the new one, respecting the pin layout (there's always a dot or half dot in any chip, it shows how to align it with the socket, basic stuff). Note: you can use any double op amp on the LD, or even two singles using a double-to-single adapter; there's lots of models sold on ebay for $1-3, let me know if you need some suggestions. - adjust jumpers & switches for the tube family you're gonna use (double check if needed) - close bottom plate (or just lay the whole amp down on the table, with the bottom plate in place) - install new tubes - plug everything back - quick check everything's ok (checklist: switches/jumpers, opamp, tubes, power, RCAs, headphones) - turn on the amp - let it warm up for a minute - enjoy the new sound
From the two tubes (driver in front, the small one; power behind, the big one) the driver tube is supposed to add more coloration to the sound, working as a filter, while the power tube takes care of the amplification itself. Better/different driver tubes will alter the sound more than better/different power tubes, while better power tubes will (usually) reveal more details of the driver tube and "tighten" the sound, reducing undesired distortions.
- with the amp cooled down, unplug everything and wait for a few minutes
- remove power tube
- plug power and nothing else (no RCA input, no headphones, just power)
- turn on the amp
- let the driver tube burn for some hours (some people leave their DV on for days like that, I turned it on every 8h or so and let it cool for the rest of the day because don't wanna risk starting a fire on a empty office).
- turn off the amp
- unplug power and wait for a few minutes
- insert power tube
- plug everything back
- turn on
- wait for a minute or so, and try to listen if there's any hiss (mine went ALMOST silent after a week of 6-8h daily burn in)
However, DV stock hiss it's not terrible, just barely noticeable on the HD6XX/HD650 and only with no background sound at all. And it's just a low frequency tone that doesn't bothers me nearly as much as those white-ish noise hisses that some cheap solid state amps have (or try to avoid with, again, cheap cutoff circuits that sometimes won't trigger and you can easily tell whether it's on or off... super annoying). As you can see, I'm pretty sensitive to background hiss as well, and I can tell you the DV hiss isn't too annoying for me. And it noticeable improved after burning in the driver tube, so no big deal.