Engineering aside, will I hear a difference? That's always my question.
With the Tanchjim Space, I expected the answer would be yes, so I bought it. I thought I would share my experience here FWIW.
I bought this little DAC/amp/pencil sharpener for use with an iPhone 14 Pro Max (along with the necessary OTG cable). I use two different headphones, kind of. I have the Etymotic ER4, of which there are several variations. Mine are the ER4p, which was designed to be flat response and relatively easy to drive (approx. 27 ohms). But it came with an alternative connector that increases impedance and turns it into a model ER4s, which is harder to drive (approx. 100 ohms) but has less noise and a still flatter response curve, apparently.
Formerly, when listening on my phone, I used the standard Apple dongle and the ER4p setup. This sounded pretty good to me, and once I was able to add EQ through my Roon subscription, it was very good.
Now, with the Tanchjim Space in the mix, I’m adding the extra impedance for the ER4s configuration. The sound is noticeably better. I’m very pleased.
People are notoriously bad at perceiving and articulating the pros and cons of audio equipment. But I’m comfortable stating that the lows and mids sound fuller and richer -- most likely due to the added power rather than the improved DAC performance. That makes a noticeable difference in every kind of music, including classical, but especially anything with more low-end emphasis.
It’s worth mentioning that I also hear a noticeable improvement using the Tanchjim Space with the ER4p. The difference between the s and the p is I find the p a little thinner/more tinny in the treble, I think.
In short, the Tanchjim Space was a good investment in improving the sound quality from my iPhone. I would recommend it.