dCS Rossini APEX Review at HiFi Clube

dCS is promoting the Rossini APEX review by José Victor Henriques at HiFi Clube:

dCS Rossini APEX Review

What surprises me about this (glowing) review is this statement (emboldening mine):

The wide range of facilities comprises phase, channel swap and balance, and level setting – select 2V if you use it as a dedicated DAC and 6V for preamp functions or driving a pair of active loudspeakers. Levels 0.2 and 0.6 are for use with AirPlay.

This doesn’t sit well with me at all, as I use my Rossini Player through a preamp (Ayre KX-R Twenty) and it sounds much better at 6v output with better bass and improved impact.

I do know many pres can’t handle a 6v source, but if yours can, I’d highly recommend you give the 6v output setting a try.

The comment about the lower output voltages being for use with AirPlay makes zero sense whatsoever as the input source has nothing to do with what output voltage sounds best.

This was also an interesting tidbit I didn’t know, though I don’t care much about MQA:

Note: dCS informs that for the USB1 input, such as when playing from a PC, the Rossini will perform the MQA render on previously decoded MQA, but it will not perform a full decode and render. In this situation with the USB1 input, the Rossini is only performing the MQA render, not the decode as that has been carried out by the TIDAL software. But you still get a fully decoded and rendered MQA file – just that these stages are split between TIDAL’s software and the Rossini.

Finally, I admit I wholeheartedly agree with this statement, always have (but bought a Rossini Player anyway :grin:):

Rossini accepts encrypted SACD data too. But only from dCS Transports via Dual AES inputs (2xDSD). I wish it had an HDMI input that I could also feed with unencrypted SACD data (.dff and .dsd) from my Oppo Player. I’ve tried it with a Bryston DAC with HDMI input, and it works just fine.

Something confirmed by Oppo themselves:

DSD Output via HDMI:

If your A/V receiver or audio processor supports native DSD, your OPPO player can send DSD signal over HDMI to the A/V receiver or audio processor. You should connect the HDMI 2 port of the player to your A/V receiver or audio processor since the HDMI 1 port does not transmit DSD signal.

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I have tried Rossini Apex with 6V output to my McIntosh c2300 as pre. It works great indeed. So it depends on whether the pre can handle 6V. My c2300 can handle opto 9V in balanced connection.

Regards,
Sourav

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Using 6V on a preamp instead of 2V means attenuating an additional 9.5dB to reach the same level at the preamp’s output.

If you’re trying to only output 2V at the output of your preamp, sure.

This has absolutely nothing to do with it at all.

The preamp’s output voltage is determined by the desired listening level and therefore dependent of the input sensitivity of the power amp (and the speakers), which in my case is approx. 110mV for 1 Watt output @ 8 Ω, giving me a stereo SPL of approx. 75dBA at the listening position. Unlike many others, the power amp can deliver the current required by the speakers without restriction (e.g. 1W @ 8 Ω means also / 2W @ 4 Ω / 4W @ 2 Ω / 8W @ 1 Ω).

In addition, it is a preamplifier with a max. voltage gain of 18dB. The preamp’s input sensitivity for the rated output of 2V is 252mV. So the preamp’s max. output level of 7V can easily been reached with an input level of 2V.
(Due to it’s unique volume control method the attenuation setting of the preamp has practically no influence on SQ. BTW it’s s/n at 2V output is 115dB IHF A-weighted and not only 93dB A-weighted as with a McIntosh C2300. That is 10 times less noise!)

P.S. Driving my power amp with 110mV directly from the DAC as a preamp with output setting at 6V would require a digital attenuation of approx. 35dB, which would mean a resolution loss of almost 6 bits (!). This does not make sense at all.
dCS recommends to set the DAC’s output level in order to minimize the additional digital attenuation (in my case, this would be 0.2V or at max. 0.6V).
The HiFi Clube review’s recommendation for level setting only proves, that the reviewer has absolutely no idea about correct level setting.

Regardless, you should try it both ways and choose the option that sounds better.

Another option is to setup your dCS to feed a unity gain/surround preamp input so that what comes in is directly fed to the output without any volume processing whatsoever.

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What do you mean with both ways? 6V or 2V via preamp or 6V directly to power amp?
I cannot help but getting the feeling, that you didn’t fully understand my previous post.

Unity gain is electronics, which may influence SQ.
Whithout any volume processing whatsoever? There will always be volume processing somewhere in a system to set it to desired listening level.

Via preamp. Use the setting that sounds better,

True, but unity gain or processor bypass mode takes your preamp’s volume control out of the mix and you can control volume via the control on your dCS just as if it were connected directly to your amp(s).

The bottom line: the output voltage of the preamp finally sets the listening level.

With one of the two absolutely best preamps on the market there is no audible difference if you feed it with 6V and attenuate 9.5dB more or if you feed it with 2V and attenuate less. The output voltage will be the same. And so will be the SQ.
(BTW, I’m talking about a € 32k+ preamp. If you want to know more about it’s unique analog volume control, google for ‘Accuphase AAVA’.)

Why should I use the digital volume control of my DAC, when I can use the truly unique analog volume control of my preamp? Selecting ‘unity gain’ on my preamp does not leave it’s volume control out of the signal path.

Pls help me out here.

R u saying even if my preamp is capable to handle up to 9 v of input voltage I should still use the 2V output of Rossini Apex Dac ?

Regards,
Sourav

My preamp (Accuphase C-3850) is capable to handle up to 7V of input voltage, but there is no sonic difference between 6V and 2V.
I do not know about your McIntosh C2300.

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Understood. Right now I am really experimenting on that by listening to 6V output for last few days.

The challenge is in deciding the right Volume level for both cases to make them comparable so that u can judge whether there is any difference in sound quality.

In both cases I am keeping DAC’s volume at maximum.

Regards,
Sourav

For what it’s worth, I sent an email to my amp’s constructor (SPEC) and they answered that 6V would saturate the preamp input, so the right choice would be 2V.

Maybe not all customer services will answer an email, but I think most will.

Andrea

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McIntosh c2300 has this documented in the manual saying for balanced connection the input voltage can go up to 9V.

Regards,
Sourav

Ayre has also said 6V is not an issue whatsoever.

Guys, I think we have been over this before, extensively:

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As I have noted in the past “if” there is any sonic benefit for setting my Vivaldi to 6V, I will give up that minuscule bit of SQ for greater control of volume via my pre-amp. I can adjust the volume much finer at 2V versus 6V.

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Hi Guys,

The selection of output voltage should be done mainly in accordance with what the connected device is supposed to handle - whether that be a preamp or power amps / active speakers. They will have a maximum input voltage above which their input will be saturated and driven into clipping.

For example. I have a lovely old Krell KSA50 here that I can run with a 6v output but if I go over -10db on the volume control then it starts to clip on peaks, setting that to 2v means that I basically have to go 10db higher on the volume to get the same level but I don’t hit clipping.

If you are going into a preamp then simply set the volume on the (in this case) Rossini to 0db and select the appropriate output voltage so as not to overdrive the inputs to your preamp (some older kit have inputs that saturate at 1v RMS so in that case you might end up using the .6v option)…

Now, you CAN do a bit of tweaking using the output voltage selector too (which is what Jim is doing above) … lets say that you have your lovely setup but that most of the time you have sufficient reserve power in hand that you are listening with the volume well down down at -50db (or whatever) then you can try setting the output voltage to a lower level (.6v or .2v) to enable you to bump your normal listening level further up the volume scale and you MAY feel that you prefer the sound of this.

Ultimately it’s what sounds best TO YOU without overloading the input to your downstream equipment…

(…and yes, I know that in my childlike heart I much prefer seeing my Rossini sat playing at -11db rather than at -1db because it lets me think that I’m not pounding my system as hard as I know that I am doing but knowing that in venturing beyond -10db I’m likely to start clipping the amp on 0db peaks is also worrying.)

Cheers

Phil