Running DCS Vivladi DIRECT?
Hey Folks,
Anybody out there who cares to comment on running the Vivaldi DAC direct to the Power amp.
Please compare with running through your favorite preamp and elucidate the differences.
Thanks & keep enjoying our hobby!
charles1dad Give it a rest Charles, same goes for you too, the other way round, can’t see the forest through the trees.? Look at the heading of the thread again! And it’s not by folkfreak. Johndoe is answering to the question by sthekepat the OP of this thread! "Running DCS Vivladi DIRECT?" Cheers George |
Big difference between you and I George. I can easily accept the fact that people can and will choose either approach. If someone prefers DAC direct I don’t 2nd guess their decision (why should I?) . You on the other hand are dogmatic in your opinions and display a tendency to belittle those who do not share your viewpoint or attribute it to "pleasing" coloration. As pointed out previously DACs direct to amps presents their own inherent coloration and shortcomings, You aren’t experiencing straight wire with gain. Don’t fool yourself. These choices we discuss are "all" sonic tradeoffs. Cheers, Charles |
By the way the OP ask for "comparisons and to elucidate the differences. This is what folkfreak did in fact do.Well don’t jump on Johndoe’s case for doing just that, forest and trees. You aren’t experiencing straight wire with gain.No it’s straight wire with NO gain, even better as there's no gain circuit. |
Fair point @seigen but the other consideration is level matching with my phono stage. With the current settings the two need the same rough preamp volume settings and so avoid the danger of playing too loud. Gain matching across the entire amplification cascade is an interesting topic and one I’ve previously commented on (albeit in the context of phono) |
Why do you need to match the output level between your DAC and phono stage? I mean, are you doing on the fly changes between inputs on the preamp while listening simultaneously to your TT and DAC? In that case the Vivaldi would be quieter than your phono stage at the same volume level on the preamp. The 0.2V setting on the Vivaldi might sound better when run direct into the amps since you'd hardly get to use the volume control at all, keeping it mostly at max. |
Why match? To avoid having to remember to add or cut 20-30 steps on the volume control or risk playing way too loud. As it stands the two inputs use the same range which is what I want. Also we want to avoid at all costs using any gain at all in the pre-amp and reducing to 0.2V would mean needing to use almost the full gain stage (12dB) to get 0.7V rated output (not that I of course drive the amps that high but peaks may) while 600mV is much closer to the desired 0.7B output sans gain ... make sense? In other words the volume control setting and cuts I describe represent the average, the peaks may be close to unity |
Plus I should add that the test tone I used for level setting is -20dBFS so if you like the peak you are actually hearing with 14dB cut is +6dB This all gets confusing which is why I always keep my gain cascade spreadsheet handy and check all the levels so that I get as close as possible to 0dBFS at power amp input sensitivity at the level of preamp gain I prefer |
If you attenuate between 9.5dB and 14dB on the Vivaldi with the 0.6V output setting going direct, running 0.2V into the preamp won't need its 12dB gain at all. Using your preamp you first attenuate the signal from the source and then amplify it back to the level required for your listening anyway, since you're forced to apply the preamp gain to the signal no matter what. (the gain stage in your ARC preamp is fixed not variable like in Ayre's preamps btw) If you have a TT you need a preamp anyway and it's irrelevant to the discussion what output setting you prefer on the Vivaldi through the preamp for various reasons; the discussion is about differences between DAC direct vs preamp and I think the Vivaldi direct should be used in its optimal configuration to the amps in question, for the result to be as meaningful as possible. My take is that if you wouldn't prefer the Vivaldi direct on its 0.2V output setting to the preamp route, you don't really like how the DAC sounds and prefer the coloration/enhancement that the preamp gives you. |
I’d try the 0.2V output setting on the Vivaldi if you attenuated between 9.5dB and 14dB; this way you’d be able to run the volume control to max, with no more than 5dB of attenuation. Yes seigen has the right idea, this way you run minimal risk of "bit stripping" Wadia and ML know about it. Here is what Wadia says with their digital domain volume control products, also Mark Levinson has the same instructions with theirs. As they both have gain setting links on their analogue output buffers, so this is level preset to allow the sources digital volume control work at near full volume with no "bit stripping" https://ibb.co/kc4OCo Also a very true and correct statement by seigen with a band-aid fix at the end. My take is that if you wouldn’t prefer the Vivaldi direct on its 0.2V output setting to the preamp route, you don’t really like how the DAC sounds and prefer the coloration/enhancement that the preamp gives you. Cheers George . |
Will you guys please get of your hobby horses and do some simple maths. My amps rated sensitivity is 750mV. The 600mV output of the (0dBFS) of the DAC preserves as much of the potential dynamic range in the signal without needing either attenuation (acceptable but undesirable) or amplification (always and in every case undesirable) When using a test tone at -20dBFS my preferred volume settings were in the range of -9 to -14dB -- now no one listens to test tones, we listen to music with dynamic range -- in the case of the dynamic range database the peak to median level for the Stacey Kent track I use is 14dB (which by the way I play at the -9dB setting) -- if we assume (which is wrong) that the test tone represents the median (it doesn’t as test tones tend to need to be played lower than music) then the setup I have corresponds to peaks almost exactly hitting unity gain I know you people believe that in all circumstances a preamp is bad but none of you have offered any explanation as to why the direct connection appeared to limit dynamic range and cause the peaks in the tracks (especially vocals) to harden? ps interesting that only now do you talk about bit stripping .. of course by using the dCS at 0dB this problem is avoided, plus I understand that the implementation of the Vivaldi DAC avoids this issue ... |
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Sorry, but you're confused. If you keep the volume on the Vivaldi between -9-14dB for a -20dBFS signal, the volume level on the Vivaldi will still be at -9-14dB for a 0dBFS peak signal. The attenuation level stays constant irrespective of the source's signal amplitude, the same attenuation level is applied to a -20dBFS signal and a 0dBFS signal. -20dBFS signal + 9dB attenuation = -29dBFS signal 0dBFS signal + 9dB attenuation = -9dBFS signal So you always listen at -9-14dBFS peak levels. Keeping the volume between -9-14dB on the Vivaldi for the 0.6V setting means the output level is too high. |
@seigen please read page 14 of the Vivaldi DAC manual, -10dB is dCS’ highest recommended level for direct connection https://www.dcsltd.co.uk/wp-content/uploads/2015/06/Vivaldi-DAC-Manual-v2_0x.pdf |
Here’s another way to look at it, maybe this way you’ll get it: 0.6V @ 0dBFS = -2.21 dBu 0.2V @ 0dBFS = -11.76 dBu Now apply 9dB of digital attenuation to the 0.6V signal, you get: -2.21dBu - 9dB = -11.21dBu = 0.21V So whether you use the 0.6V (with 9dB of digital attenuation applied) or the 0.2V (with no digital attenuation) output setting, the DAC outputs the same voltage basically at 0dBFS. |
Fine -- and when I change my phono stage and drop from 45dB gain to 40dB the 0.2V may also be a better match than the 0.6mV But still no explanation of why the direct connection does such a relatively worse job of handling dynamic range (if we put all the soundstage stuff down to coloration, which btw I wholeheartedly do not) -- and no it’s nothing to do with the -9dB cut as the dCS volume control is digital and non bit stripping |
@georgehifi -- I'm very happy with the verdant, lush, wild and exciting primal woodland panorama my tube based active pre-amp gives me thank you very much and will not be spending a moment more worrying about fussing with going back to a direct connection Having said all that spinning vinyl has turned out to be so much more rewarding these last few days -- loving the Weitblick Peinemann WDR releases for example |
folkfreakFunny you should mention vinyl, I also love to listen to it now and then especially on old stuff like Beatles ect which kills the digital of the same thing, which tends to be cold and very pin-pong from left to right, and no bass or body to the vocals like vinyl does. So I knuckled down to find out why I preferred it with old stuff over digital , besides all the clicks and pops, was the channel separation. So I concentrated on the channel separation of vinyl, and at best it’s 30-40db at 1khz, above and below that, it worse almost mono in the bass, digital is over 100db separation across the audio band 20hz -20khz in most cases So what I did was make a switchable network circuit to bleed the left into right and visa versa on the output of my cd player to blend the channel separation from 100db down to 30db and instantly you could hear those old Beatles, Beach Boys, ect come to life. Almost gone was the exaggerated ping-pong effect, the bass was richer because it was "mono’ized" and the voices had more body because the of the richer bass, the only down side was the image wasn’t as spread across the room, which is also understandable, because of the "mono’isation". But all this and still no clicks pops and surface noise, it’s a winner. This CD/digital "vinyl mimicking" circuit with far more complexity would be even closer to vinyl, if below 1khz the 30db it would follow the vinyl’s worsening channel separation in the bass and treble. Cheers George |
It must be very sad to believe that everything we find attractive in this hobby is an artifact or coloration ... I found this a very interesting piece on how our hearing works https://www.scientificamerican.com/article/theres-an-inverse-piano-in-your-head/ |
It must be very sad to believe that everything we find attractive in this hobby is an artefact or coloration Ah yes, but not sad, just understandable, As I said this was only with old stuff Beatles, Beach Boys ect. that was recorded and voiced with no digital involved, and where the "channel separation null’ing network" worked a treat with digital. With later stuff recorded and voiced on digital equipment, the null’ing circuit is definitely better left out, and to me far better through the digital gear, and not through vinyl. Cheers George |
@georgehifi That's a very good piece of analysis and detective work George. I am particularly impressed that you could actually design and implement a circuit to do what you did. For a rock kicking civil engineer, I am always amazed at how electronics work and how it all fits together. I think I should have studied a different engineering stream. Well done! @folkfreak A very fascinating article. love the science in it. |
Easy to do simply on a scope using test bench cd's, just a flat across the board 30db channel separation with resistance across left and right channels, but to get it follow like a cartridge takes quite a bit more complexity. Bit of a channel separation discussion on the Vinyl Engine https://www.vinylengine.com/turntable_forum/viewtopic.php?f=19&t=44346 Cheers George |
