xDuoo XD-05 Plus Portable DAC / Headamp Review and Measurements

The dual should fit. The singles x2 I am not too sure about.

 

Just an update to the noise. With the Pixel 2 as the USB source, it quiet with nothing else turned on. However the USB Audio Player app when its playing something, and only when it's playing something, has a barely audible whine. Obviously this isn't an issue most of the time when there is music playing, but I can make it out in parts where there is no audio signal in the track.

Whatt makes things even more interesting iis when using Qobuz app is different - because of the 44.1kHz to 48kHz upsampling on Android, the level of the noise is different, less of whine, so not as noticeable. I gave my ears a rest to restore their sensitivity for this test.

I will try from a computer source next.

 

Got the OPA828. x2 mounted as a dual on a single adapter. Yikes, I do not like this. Everything sounds loud. The bass is farty loud. The highs are very much there, almost in your face. Tonally it isn't difficult and I don't want to call it V-shaped. Just too fake "hi-fi" vivid mode sounding for me. This was disappointing.

To summarize in regards to the Campfire Solaris IEM, I prefer the OPA627x2 and the OPA1656. The former is laid-back and mellow sounding, yet articulate and detailed. The latter is less colored, more normal sounding but the strong heft in the lows. It exposes the balanced armature timbre in the highs, but it's not bad at all because there nothing is added on top exacerbating the situation. Normal sounding is good. The OPA2134 is an honorable mention for something cheap that has some of the mellowness of the OPA627.

 

@purr1n That's interesting! Anywhere I tried the 828 I just found them so dull, flat, and soft. But, hey, circuit matters. 1656 so far just works well in about any situation. I agree with your assessment on them.

Opamps are fun to mess with if you buy cheap ones and don't get weird about it. Can teach valuable soldering skills too.

 

• Either what you or I had could have been fakes
• Dull and flat can either compress down or compress up - in my case, they compressed up. Samsung Vivid mode. The cost of the OPA828 is dumb, dumb x2.
• OPA1622 may be interesting.

 

OK, so it seems like that tiny whine may have come from the OPA1656. It's possible there could be some oscillation because of this part's super high bandwidth. With OPA627, I did not hear any noise than environmental. Note that I live in a high-noise area with small planes flying a thousands of feet overhead, birds in the back yard, trucks rumbling down the highway two miles away. The environment noise is not loud, but one does get bombarded with it and thus lose some senstivity. If you live in Austria, in the hills, near the Von Trapp family, it may be different.

As far as the boost, I confirmed that output impedance does not change. It appears that when the boost is off the unit puts a limit on the current. Think is boost as releasing the power limited. I did not perceive any difference in sound with the Solaris 2020. Zout for the xDuo measures just a little bit more than 4-ohms! I assumed it was near zero, but this is not the case.

Below is the difference with the Solaris 2020. Other CFA IEMs such as Ara and Andromeda 2020 will perform very similarly.

Solaris 2020 FR
ORG = xDuoo-XD-05-plus, approximately 4-ohm source impedance
GRN = Schiit Fulla 2, approximately 0.5-ohm source impedance


I did not get a chance to hear Andromeda 2020 from the xDuo, but I feel it's slightly higher output impedance will be beneficial because the Andromeda 2020 was just slightly too dark or too bassy for my taste. In any event, there are a zillion opamps that can be rolled to alter perceived tonal balance, timbre, and transient behavior.

P.S. I knew I forgot to do something! This official concludes the review and measurements. Unless there are additional requests.

 

I tried it with FDX1. It works and no noise. A bit bassier than I would like. The ideal one would sound lean and tight I the lows while taming the shrillness of the upper mids.

 

I'm thinking the OPA2134 would be better for FDX1, maybe not so dark. The OPA627 dark / mellow tonality can impede the perception of clarity, which I feel the FDX1 really needs in the lows.

From memory, the FDX1 seemed more veiled in the bass than FD-01 modded. @shotgunshane or @Kunlun: Did you guys feel this way? I don't know you if were on the FD-01 loaner. This is one of those things were I don't know if I am imagining things. It could be unit variance too.

 

The modded FD01 was the one with the hazy bass. All the prototype FDX1s, that used the FD01 housings, had the same hazy bass. But all those prototypes were literally FD01s with JVC tweaking filters. The production FDX1 was the only one I heard in the new housing. It’s was noticeable tighter/fast sounding than everything previously. Later I purchased my own FDX1 and it’s what I have to today. I find it’s bass one of the faster, cleaner sounding dynamics. I have no idea what JVC did between the FD01 and FDX1, besides housings and filters, or if it had any impact on future FD01 production.

 

Most definitely. The advantages of the iFi Micro are with the changeable filters including BitPerfect and the built-in iFi IEM matching thing. The XD-05 Plus is more polite sounding relative the IFi Micro BL which more incisive. Overall I feel the iFi has better sound quality and much better fit-and-finish, but its sound can't be tailored with opamp rolling like XD-05.