Ok so, I did a test. I’m confused. I need your input to figure out what’s happening. I mix and match 3 DAC/AMPs with 2 IEMs. The question I have is that, if DAC/AMPs are supposed to be transparent, aka outputting a flat FR, what else can affect the tonal balance in the chain?
Gear list:
HIFIMAN EF600(Low Gain NOS), Cayin RU6 NOS, FiiO BTR7
Truthear Hexa, Moondrop Aria 2
I tried my best keeping all the volume same, vocals especially. The EF600 has A LOT more bass than the other two, but also having a much clearer instrument separation and clarity, by a great margin. BTR7 has somewhat good bass while RU6 has the least. RU6 has the least clarity as well.
I know this may sound obvious, “Duh, DAC/AMPs are different.” But I’m wondering the root cause of this, like is it because they output different non-flat FR? Or is it the output impedance that’s affecting the sound? I specifically used two IEMs with different setups, single DD and 1DD+3BA, the results are exactly the same so IDK if it is impedance. I’m curious what’s behind this. I know RU6 has very bad THD so a lack of clarity can be explained. BTR7 has better THD on paper than EF600 but the actual perceived clarity is audibly lacking. It could be IMD or something else but the drastic difference of tonal balance is beyond my understandings.
If the EF400 is indicative of hifiman standards, I wouldn’t expect great things from the EF600 measurement wise - https://www.l7audiolab.com/f/hifiman-ef400/
Honestly none of these measure that well compared to other options out there, if you’re looking to power IEMs then I would look towards one that measures cleanly e.g. moondrop dawn/dawn pro, tanchjim space, tempotec sonata bhd pro. When you have messy measurements I’d imagine tonal balance would be affected as well and not just clarity, but I’m not sure in what way
Yea I’m wondering how the EF600 measures but I can’t find anyone doing it. Hifiman has EF500 and EF499 now as well. The EF400 uses a worse r2r chip so I assume other ones should be technically better, especially when correlating to their price. After all, they are r2r so they’ll always measure terrible compared to delta-sigma ones. But measurements aren’t everything. The btr7 was in wired mode and it has much lower THD than ef600 as claimed by manufacturer. But I still think the ef600 sounds more “resolving” and “natural”. It could be placebo tho since it wasn’t a blind test. At that low level of THD I doubt it would be audible anyway so it’s probably something else.
Nos modes usually don’t measure flat, they usually have treble roll-off. The Ru-6 measures like dog doodoo so it sounding different is not hard to believe. I remember the ef400 in nos mode having treble roll of and also having issues with left-right channels being not in phase(don’t play at the same time), and I wonder if the ef600 is the same case.
I wish someone did a measurement on the EF600. I tried the ef400 a while ago and I couldn’t hear the phasing issue. Maybe it was product variance or I wasn’t trained enough to hear it.
I have the RU6 and RU7, and they both lack clarity and resolution when I drive them with through my laptop with the stock cable. Oddly, they both sound best through my iPhone connected with a DDhifi09s lightning cable, the muddiness clears up and everything is crisp and detailed.
I’d pick up a DDhifi usb-c to usb-c or usb-c to lightning cable and try it. If you get it from Amazon you can just return it if it doesn’t work, but it was a big difference for me. I’ve also heard of people using USB purifiers to handle the noise.
Are you sure it’s not placebo? As far as my understanding goes, it’s technically impossible to have “sound quality” variance on a digital cable. It’s just ones and zeros. If it fails to transmit the signal as it is, it will probably click and pop. Analogue cables could sound different because of their impedance.
Definitely not placebo, the difference is as clear as day. Most cables transmit power and data through the same wires, the DDhifi cables split the usb power and usb data into two separate, shielded paths.
I love how redditors want everything to a placebo so they don’t have to spend more money. 😂
Oh please don’t assume that. I’ve spent a lot of money and I don’t mind. I will try the cable. It never hurts to try something new. At least for me, it’s not saying everything is placebo. It’s because placebo plays a huge part in this hobby, so keeping in mind of its contribution is always a good idea when looking for something more objective.
The ef600 has 32 ohm output impedance. That’s going to have an effect on the FR of almost every IEM on the market.
Can you please provide a link to that? I’ve been searching for its impedance but haven’t found any info.
I can’t find a reference to its output impedance. Seems very unlikely since the amp will likely be paired with hifiman’s low impedance planars.
I can’t either. But even if it’s true, those planars have flat impedance across all frequencies so it wouldn’t affect them anyways, unlike most dynamic drivers. So it could be true in this case imo.