I pick up Monoprice THX 887 amp and check it out
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Has anyone listened to the D90 against the Bifrost 2? I am going to pick up a new DAC for my rec room in the coming weeks. Both the Bifrost 2 and D90 look interesting to me for different reasons.
I have had the Gumby which I was not crazy about, the Holo Spring which I loved, and a bunch of āhifiā ds dacs which didnāt last long here. I am now running an RME ADI-2 DAC FS in my work suite. It took a bit of getting used to, but love it now.
The rec room system has a Heed Obelisk SI 3 and a pair of BW606s. I will be using it for movie watching, giving the kids something to listen to, and for my own listening. The BWs are fun. They image and stage quite well but can be a bit sharp with the wrong DAC/amp.
I am quite fond of using HQplayer to upres materials to DSD as I find it possible to tailor the sense of staging and imaging to suit the material by using different filters and modulators. The RME responds very well to this, as did the Holo Spring.
I know that the Bifrost 2 is PCM only and youāre locked in to their filter which makes me a bit nervous. I also think it might be liberating to not be tweaking all the time.
I have read a number of positive reviews that describe the sound of each and think I have some data there. I have also read through the Bifrost2 vs RME thread. I am hoping, based on my reading, that there is a āfamily resemblanceā between the RME ADI-2 and the D90.
I have, however, read that the Topping DACs are not great. @Torq and others have been vocal about the limitations of the Topping DACs. Does the D90 also have the issues described with the D70, D50, D7x etc (flat sounding, mechanical timbre, fatiguing highs etc)
If anyone has listened to both the BF2 and the D90, how would your describe the difference between the two?
I know I will ultimately need to gauge things here in the system, but I would be interested in peopleās experiences. I will start with either the BF2 or the D90 and go from there.
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The D90 is effectively indistinguishable from the RME ADI-2 DAC FS. You pay less since it is just a DAC. If you only need a DAC, itās a viable option.
If you didnāt enjoy the original Gungnir MB then, unless you were using it via its single ended outputs, you probably wonāt enjoy the Bifrost 2 either.
Toppingās DAC/amp offerings have (to date) pointlessly high output impedance so theyāre only suitable to use in that form with higher impedance headphones. But you an just buy a DAC-only version with a proper amplifier.
Iāve no issue with the D90. The D70 was fine, but a bit pointless given the existence of the D90. The D50S is okay if you run it with lossless content - but Iād pass on it entirely for use with Spotify (specifically) unless youāre okay with running it at - 3 dBFS. Itās not my thing, but it is technically competent.
The D90 is the only Topping DAC I would personally consider, but Iād rather have the RME.
The ONLY DACs I would bother with for use with HQPlayer would be TRUE NOS DACS. And of those you mention, that is ONLY the Holo Audio stuff. Otherwise they are ALL applying their own oversampling, noise shaping and filtering (NOS mode on the RME is NOT true NOS).
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This is very helpful to me, @Torq. As a test, I will bring the RME home and see how it sits in that system.
Not to contradict your experience with HQPlayer, but I have had very good results with HQ Player and DSD on the RME when (and only when) using the DSD Direct Mode. Apparently this is a feature of the AKM chip they use. I spoke with Matthias at RME and he said that DSD direct mode does not convert the DSD stream to PCM and thus bypasses all of the RMEās internal processing and filters. The RME, as a result, is āwarmlyā recommended by Jussi Laako from Signalyst (HQPlayer).
I wonder if the topping D90 has the same āDSD directā mode that does not convert DSD to PCM. I will do some digging and report back.
In any event. Thanks for your input. I appreciate your time and thoughts about the D90.
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The DSD Direct mode doesnāt bypass the RME unitās DSD noise shapers or modulators. It simply bypasses conversion to PCM prior to actual analog conversion, which renders the RME unit a PURE DAC and defeats every other feature (EQ, DSP, Loudness, volume control). If youāre always feeding it via HQPlayer, I would buy something else.
if you like HQPlayer with the RME in that mode, thatās all that matters. But that mode doesnāt avoid the RMEās DSD noise shaping or modulation, so those are being applied after the HQPlayer ones either way.
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Ah. Thanks for the clarity here. With the RME, I do like the DSD direct sound for pleasure listening. For work itās all PCM over AES. Itās the best all-rounder Iāve met.
Iām still digging around about the topping D90 and DSD direct. I would be using it as a DAC only.
FWIW, I reviewed the configuration of the system I used with the Gumby (April/May 2018 new from Schiit I believe this was Gen 5/A2?), and I was running it SE into a Heed and Harbeths. I was not in love with the sound of it at the time. I now understand that the SE outputs were not up to par with the bal outs.
Are you sure SE outputs are bad? I use D90 with T4 amp ( connected via RCA). Nothing seems to be wrong with the sound.
Theyāre not ābadā, theyāre just not as good as the single-ended outputs (since the native topology for the Gungnir MB is balanced, and the single-ended outputs are derived by summing the balanced outputs).
Also, weāre talking about the SE vs. XLR outputs on the Gungnir MB, not the D90.
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Well, not only is the Gungnir MB not at its best in single-ended output, the Bifrost 2 has a signature that is closer to the original Gungnir rather than the A2 version.
As for the D90 and a āDSD Directā mode ā¦ reading the AKM 4499 data-sheet, as long as Topping havenāt done anything stupid, when the DAC is in pure-DAC mode (no "pre-amp - i.e. the 4499ās digital attenuator is disabled), and is fed native or DoP DSD content then the 4499 should be in āDSD Directā status.
Which means it is still using the 4499ās on-board modulators/noise-shapers/filters (thereās no way around that, that I can see), but is not doing a conversion to PCM first.
That said, it IS possible to set the 4499 up so that the attenuation is disabled and still have it operate in non-DSD direct mode with DSD content.
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Thank-you, @Torq. This very useful.
I have a note in to Jussi at Signalyst to ask about the practical implications of using HQPlayer with AKMās DSD direct mode vs something like NOS mode on the Holo Spring.
I know that, with the RME in DSD direct, I am able to use the various filters and modulators in HQPlayer to ārefocusā the sense of staging and imaging with headphones and especially when using powered monitors. I am curious about Jussiās take on how HQPlayer interacts with AKMās onboard modulators/shapers.
If I went the D90 route, I would be using is as a DAC only.
I will do some more research about the OG Gungnir MB vs the subsequent revisions.
Thanks again for the insight.
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Being a guy who likes to understand why I like something, I have a bit of lockjaw on the DSD Direct thing right now as it pertains to the AKM chip used in the RME and, hopefully, the Topping D90.
I had an exchange with Jussi (developer of HQPlayer) about this on another board and he confirmed that, in DSD Direct mode with the more recent AKM chips (along with a few others), the DSD stream bypasses the on-chip modulators/shapers and sends the DSD Stream directly to the reconstruction filters.
I should have done this in the first place rather than bothering you all, but I researched the the AKM block diagrams for the 4990, 93 and the new 4499 used in the Topping D90. They do layout DSD Direct behaviour in which the input is diverted directly to the on-chip reconstruction filter stage and then output to the off-chip analogue filtering.
Jussi let me know that I was confusing filtering used in the upresing process with filtering used in the reconstruction process. This is likely the source of my confusion. @Torq, when you are talking about not bypassing filtering, are you referring to the reconstruction process?
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I was actually referring to three things:
- DSD HF Noise Filter (which cannot be bypassed as far as I can tell).
- D/S Modulator (bypassed only if DSD Direct is enabled and Attenuation is Disabled)
- Reconstruction Filter
The question is, how are Topping configuring the 4499 for DSD input. If theyāre using pin-control mode, then the digital attenuation is enabled, but locked at 0 dB, and the D/S modulators are in the path. If they do it using register-control mode, and enable DSDD=1, then the digital attenuation is completely bypassed and the D/S modulators are not in the path.
One would hope (even expect) that theyāre using register control mode, but short of Topping confirming that, or having a unit here to mess about with, I canāt say.
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Understood. Thanks again, @Torq. I will reach out to Topping and see what they report and will report back.
In a parallel, non-dsd universe, I did some reading up on the V1 Gungnir VS V2 as it pertains to the new Bifrost 2. It does sound like it might suit my tastes and use case.
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I was able to side-by-side the D70 and D90 for about a week when I bought the D90. I could not describe any substantial difference between the two sound wise. I am not a golden eared evaluator, and I tend to doubt my senses anyway so grain of salt with what I say. But if i did perceive any difference it could have just as easily been other things.
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Both AKM chips correct? Does the D70 have the older chip that the older RME has?
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The RME ADI2 uses AK4493 and the D70 uses the AK4497 and the D90 uses the most recent AK4499.
Or so Google tells me. 
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That Google guy knows a lot. 
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So I have the potential opportunity to possibly exchange my SU8V2 from the retailer I bought it from as the audio constantly drops out when the Quality of the track changes via Qobuz. I also know aside from the audible click in the headphones after the drop in audio the brittle sterile sound from that unit is not to my liking. If I was able to exchange obviously have to shell out the difference 
what pushed you toward the D90 vs the D70 I just donāt want another Dac that has a audible drop in the music as well as one that is over analytical brittle or bright sounding? Do you listen to yours via Qobuz? @Andrew_Davis
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Great impressions @angstorms are you still enjoying the D90?
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I use Tidal and Amazon to stream and not had problems, but Iāve never tried Qobuz.
I bought a super low distortion,sterile,neutral, latest AKM chip DAC because this audio stuff is complicated enough without adding extra variables! 
. What I mean by that is I wanted DAC that added as little as possible while I experiment with amps and headphones. And the D90 is very much that. Maybe once I get through all the amp headphone combos Iām interested in Iāll start playing with DACs. I mean, how long could that take?
Actually I have been spending time researching R2R dacs lately. So never say never, I suppose.
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