I am probably buying a used A90 on Sunday but now reading some owners getting noise/hiss when connecting DACs or active speakers through RCA? If I understand it correctly this is the main concern with the A90, the fuse issue seem to be really rare?
What I have today is a iFi Zen Dac connected to my computer through usb but getting power from a power supply (iFi iPower X 5V). Headphones HD 6XX and connecting them through quality balanced cables with the 4.4 mm pentaconn.
Not sure for how long I will use the Zen Dac but I plan (was hoping) on using it for a while with the A90. Do you think there is a big risk running into grounding issues connecting the Zen Dac through RCA inputs on the A90 or it's less risk because of the fact I am connecting the Zen Dac through a power supply?
Since I am not sure for how long I will keep the Zen Dac I will be very hesitant in investing in buying an expensive custom made 4.4 mm - dual 3 pin XLR cable (for a fully balanced connection).
I have no RCA issues whatsoever, never had. Even going via additional tube pre between adi2dac and a90 it is dead silent in my case. I did get rid of ground in my adi2dac USB however, which was indeed causing noise.
The only issue I had with A90 was with low impedance and hi sensitivity headphones - eg Klipsch HP-3 - these are very good for gaming (the best for sound placement, especially vertically) surprisingly and some music types but even at LOW gain and low output from adi2dac with A90 HP-3 are sibilant (going above LOW gain on A90 is just terrible). This maybe due to HP-3 being 25ohm. Anything else in my collection and up to Beyerdynamic T1 2nd gen 600ohm sounds very good. Actually T1s sound the best with the A90, which may say something about the power of this device and the attention one needs to pay to pairing devices ))
Tubes help with the sibilants as well as games imho.
Other headphones I have tested with A90 are Sony MDR-Z1R (these help me with any flu
), Audio Technica W1000 Sovereign (got those back in 2008 and they're still like new
) with Brainwaivz XL earpads and HiFiMan Sundara (just help me stay connected to the world via their transparency). All of them sound great with appropriate output/gain settings, no EQ mind you - don't like that (otherwise you drown in all the options). Only Klipsch's have a bit of a trouble with sibilants at some point but that again may be a recording/mastering issue + low impedance.
Also waiting for Fostex T60RP Argons to complete my collection ))
From what I understand most of the noise tends to come from the DAC. You need to be inside something like an atomic power station to have issues with interference through the air and into your amp (although I read otherwise in other threads). But what do I know..... besides my experience - kill me if I am wrong ))
Also there is no Sennheiser in my collection because actually there was a pair and I tried a few afterwards and they all sounded too boring to me (maybe cause I'm used to them) so I went on with trying everything else out there. Also not a big fan of planar cause I do hear plastic "aftertaste" - so no Audeze, etc., sorry about that. I tried a few times but I indeed felt like chewing on plastic.
Hope that helps.
That's not my complete review by any means but just something I felt I had to say so far in response to makatech ))
