To be clear, you are not running a passive volume control. The OPPO uses an active system. In short we're on the same page.
To answer your last question: sure. FWIW, dynamics comes from the signal not the equipment. If the equipment is messing up, you can lose dynamic impact, but if you gain 'dynamics' its a pretty good bet that distortion is playing a role (this is common with SETs for example).
If I can point something out here- high end audio is not driven by price although many people think it is. Instead its driven by intention. That is why OPPO did so well with their relatively inexpensive products. My guess is they likely priced them according to a formula rather than to what the market will bear and there was someone important in the company who was an audiophile. So answering your first question: maybe.
To answer your 2nd question- since I've run into that a lot, I've not bothered since a passive won't work right unless you put it inside the thing you are driving with it (for example inside an integrated amp).
Sorry for my delayed response. I stand corrected and thanks for clarifying. And my apologies as I was a bit arrogant or at least overly confident about that. Because of the behaviors it’s still hard for me to believe so I reached out to another to confirm your accuracy. And it seems anything I thought I read 8 or 9 years ago is nowhere to be found.
I need to ask this. Might it be possible that the OPPO units just have a lower than standard voltage at the line out? I’ve been using XLR ic’s for the past 20+ years so it’s not like I’ve been bouncing back and forth between single-ended and balanced outputs.
I ask because in my previous post I mentioned the OPPO’s volume attenuator behaving as a passive. As mentioned earlier, in 2014 I’d purchased a pair of 575wpc monoblock Class D amps. However, what I didn’t mention was just 30 days prior to that I’d purchased a 575wpc Class D integrated amp (same mfg’er) that was anything but musical yet dynamic were way over-the-top and including a horrific “jump factor” where my ears were seemingly running up to the soundstage for a note’s initial attack (in my face) and my ears running back to the audience for the ensuring decay. Entirely unmusical and since I had a 30-day satisfaction guarantee, I returned the int. amp for their pair of monoblock amps – same wpc.
I should also mention this is not my first rodeo with Class D amps as I used to sell Nuforce amps and I remembered testing my passive, dedicated, bi-directional filtering line-conditioners with nuforce monoblock amps for their bi-directional digital-like distortions induced by the amps’ high-speed switching modules. Long story short as I contemplated why the 575wpc Class D integrated amp was so overly dynamic and downright nasty sounding I remembered my experiment with the Nuforce amps and shared verses dedicated line conditioners and concluded that the 575wpc Class D int. amp had to be sharing this digital-like noise between both channels and again at the pre-amp causing this high level of unmusicality so I returned the int. amp for a similar pair of Class D 575pwc mono-blocks where each obviously had its own AC inlet. This is why I’d never purchase Class D stereo amps because I can do nothing to prevent this internal sharing of distortions between channels.
Between 2000 and 2014, I’ve owned or auditioned somewhere around 15 – 18 preamps including a couple of passive pre-amps and also owned / auditioned maybe 12 – 15 amps. Upon receiving the 575wpc monoblock amps and switching to the OPPO’s volume attenuator, this was by far my most musical config right outta’ the box.
Anyway, having said that I can now elaborate on my prior statement that the OPPO behaves like a passive pre. Because when I replaced the 575wpc Class D integrated amp with a pair of Class D 575wpc monoblocks (same mfg’er), I was able to install one passive, dedicated, bi-directional filtering line conditioner on each amp. IOW, no more sharing of distortions between L&R channels. And by using the OPPO’s volume attenuator, seemingly no more added distortions at the pre-amp stage and those added distortions being amplified there.
Bottom line is, with the OPPO‘s volume attenuator and monoblock amps, immediately everything recessed entirely back onto the sound stage where it belonged including a note’s initial attacks with my ears firmly planted in the audience where they belong, hence the perceived more natural dynamics. No more in-my-face initial attacks, no more overbearing electronics-induced jump factor, etc, plus the notes were more pristine, delicate, etc. IOW, typical behaviors I’d expect from a passive pre.
I can’t find the specs but for this reason I have believe that since the OPPO volume attenuator is not passive as you say, then I'd have to guess it's producing a lower output voltage at the line outs. Maybe somebody else can confirm that but I can’t seem to locate any such specs for 105d or 205.
Regardless, based on my experience, there seems to be something passive-like about the OPPO that when mated to high-powered amps, makes for a rather musical and dynamic presentation.
Anyway, my apologies for being flat out wrong. But because of these experiences I have to believe something is different at the OPPO… like a lowered voltage at the line outs, less signal amplification, or perhaps something else???