How hot the TT2 runs will be a mixture of the digital processing being done by the DAC and of the current delivered to the output device. This current depends on the TT2 output voltage as indicated by the volume setting and also on the impedance of the speakers, headphones or amplifier it is connected to.
Having a TT2 connected to the input of an amplifier will result in the least current being delivered by the TT2 no matter what the volume setting (even very high) because of the high impedance of the amplifier input.
A TT2 connected to headphones will supply more current for any given volume setting but this will still be a small fraction of the current supplied to speakers at the same volume setting.
Therefore even on low volume settings the TT2 will get hotter when connected to speakers. For instance with your example of you listening with TT2 on volume -25 connected to speakers, it will run hotter than say a TT2 on volume +3 connected to the input of an amplifier.
I am actually messed up about the current (amps) situation. I am thinking of abandoning direct drive and going back to an amplifier, although my thinking could be totally wrong.
What I was thinking about was how quality hifi amplifiers are designed to be able to deliver high currents. (At high impetus too.) Amplifiers have large toroidal transformers, and e.g. Simaudio, use oversized transformers. That's so they never run out of current. The theory being lots of current delivery to speakers.
The TT2 will deliver bursts of current fast if it needs it. However I am not sure it really designed for this kind of load; but that's where I am confused. To listen to the TT2 like this, you would say it is OK. It sounds great, and contrary to N Quarter on RCA single ended, there is real bass. Or to be more accurate I think, there is the right amount of bass at the volume I am using.
It may be that the TT2 is really only OK driving very efficient speakers. Mine are not that efficient though at only 86 dB. What I don't know enough about is the characteristics of my speaker's load. Or the TT2.
Like with IEMs they say they need current because the impedance is low, so current flies around. However contradictory to that, IEMs do not need much gain, so less voltage is used. Meaning less current. … I can't get it straight in my head.
What I know is they say good amplifiers can provide lots of current if needed. I would say my speakers are on the harder to drive end of things, with low sensitivity. What it means overall is that I am nervous about running speakers straight off the TT2. Given a quality amplifier and quality RCA, might equal quality drop over TT2 speaker adapters; it's a toss up. (What I don't want to do, is put my TT2 under any risk.)
There is no denying though, that the TT2 sounds excellent driving speakers. It's enough of a step up, that it's going to take time to fully get used to.
Glad to hear you finally got around to trying this GreenBow. I found that using the XLR output was much more to my liking,I struggled to hear any loss in transparency when I switched from RCA to XLR, but the bass really filled out, much better overall sound, and immediately I just knew this was the right way to go for my current speaker 86 DB’s/4 Ohm. I am hoping to take a trip to my dealer in the next few weeks to try a few different speakers driven this way, I will bring my cables to use, he has a TT2 on site. Are you using an Mscaler in this setup? I still don’t have one, just TT2 direct. I also plan on listening to a couple of amps with the speakers I demo, in case I prefer the sound that way. The amps I intend to try are pretty high end, Nagra and LFD, so that should give me a good idea of where the TT2 direct stands compared to top notch amplification. The speakers I want to demo are Harbeth compact 7 ES3, Proac Tablette 10 signature and Kudos super 10. Good luck, and keep us updated on your findings.
Actually in the lasts edition of one of my hifi mags, they mentioned the Kudos Acoustics Titan 505 again. Someone was asking about speakers. They replied saying given their review of the Titan 505. Customers interested in speakers at this price point, should grab their card and run to the nearest Titan dealer.
I might end up going RCA because they would be easier to wire. Although the RCA plugs I have might not take thicker speaker cabling.