1. HD58X ($150) + no AMP/DAC
---
2. HD6XX ($200) + Liquid Spark ($100) + SDAC ($80)
My wallet likes the first option. However, I fear that I'm not giving my listening experience a fair introduction without getting familiar with a designated Amp and DAC.
May I have your thoughts on which of the two is a better starting point? I am also open to other recommendations.
You could get the HD58X with the Liquid Spark and SDAC.
But it's better to choose the headphone based on the tonal balance you can live with or prefer, along with any other compromises (I prefer that terms over "sound signature," because that is essentially just "what the engineering team can live with given the research budget and MSRP"), since, barring absolutely crappy equipment, that's going to be 80% of the sound already, with the amp just lowering the noise and distortion levels, and the DAC lowering noise and maybe helping imaging (maybe).
Thank you! Regarding scalability of 6XX vs 58X , does that go hand in hand with impedance? In other words, is it the case that low impedance headphones are both more drivable and less scalable? And is this the main difference between 6XX and 58x?
Scaling has a lot more to do with sensitivity/efficiency and transparency.
Impedance is only somewhat related to sensitivity and efficiency. Used to be using a higher impedance voice coil was one of the common ways to increase the sensitivity, with the added bonus of preserving amplifier damping factor (hence reducing driver distortion) thanks to very high output impedance as per Euro standards, but the penalty there is that as high as the sensitivity is, power delivery from the amp will also drop. Depending on how drastically power drops as you increase the impedance, in some older amps, even an AKG K701 will get louder, but it has higher driver distortion thanks to its low impedance. This isn't a common problem anymore thanks to better amp designs that are more widely available.
Now if the sensitivity is low you need more power; if the sensitivity is high but so is impedance, you need a fair bit of voltage and gain, meaning either a better amp design that doesn't drastically drop output as impedance rises, or one that starts with waaaaaaaaaaaaaaay more power at lower impedance (or an OTL tube amp that has its output biased towards high impedance at the cost of current performance), since as much as high impedance tends to make for lower noise and distortion, some amps don't output that much by that point and you end up cranking it up to make the noise floor audible or even clip the signal. Either way, coupled with reasonably flat response, a better amp will make such headphones sound better than say if you were to put 5mW out of a smartphone or 1000mW out of a Schiit Asgard into a very high efficiency bundled earbuds that have a narrow and/or jagged response that will still sound like crap, only louder, as opposed to either headphone example where an amp not running out of steam on either will now get you cleaner output.
Think of it like how you can have a lightweight FWD car like some econobox from India or SEAsia, and then you put a Lancer Evo turbo I4 engine on it, and it will still suck. The other headphones are kind of like a sports car chassis with a heavier drivetrain even on the same engine as the econobox since it has a longer wheelbase and a driveshaft for its rear wheels. Put the Evo turbo engine in there or a V12 and it's still going to handle a lot better and go faster than that econobox.
