Ted has mentioned that the XLR output voltage of the Mk2 is 4V, which is double of what’s regular (RCA).
Don’t know about the output voltage of the Topping, but that might explain things.
The Topping Velvet has selectable output voltage of 4 (default) or 5 volts…it is said that the 5 volt setting has higher signal to noise ratio.
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Topping balanced output can be selected to be 4V or 5V but I selected it to output 4V and thus should be the same as dac 2.
Ok, thanks. No differences there. I’m out of other clues.
As far as I understand it, it’d be no good to me having a higher signal to noise ratio if the amount of noise is so high that it becomes offensive (I’d need to try a Mk2 to compare the amount of noise coming out of it given that I’m active and have efficient drivers connected to my Mk1 dacs).
I had a piece of 3M AB7050HF 9,5cm by 17cm (3,74" by 6,7") which i used on the left side in same orientation as you have suggested.
I agree it works very nice 
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To use the DS MK2 without a pre-amp, it helps a lot to have audiophile -20dB attenuators in the XLR chain.
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Higher SNR…at a given volume noise would be less
My opinion on this topping vs MKII is that Topping designs to pass this tests. ASR has created a topping cult that counts for much of their sales. Note that a topping is a very high value product but they target those tests.
Ted does not care about those tests. He cares about how it sounds in the end.
I do have a question or guess. Does topping shut off the output when there is not signal? Simple way to pass that test.
I am a big fan of Topping. Just because ASR like them, I won’t hold it against them. I use them for completely different purposes though than I use a PSA DS MK2. For my office PC. Or in active four-way stereo crossover, an 8-Channel Topping DM-7 is cracking good.
The noise is there at all times, i.e. it’s a base noise that’s there regardless of signal volume, which is why I’m concerned.
could it be as simple as 60 cycle hum…or whatever your AC frequency is in UK?
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It’s like a white noise. I use three DSs, i.e. one for bass, one for mid and one for treble, so, I actually get the noise from three DSs. The bass drivers will only output stuff above a few hundred Hz, the mids a little higher and the tweeters a very obvious hiss. As far as I know a preamp, for some reason, filters out the noise. There’s no way I could add an attenuator as I need all the balanced output that a DS MK1 can produce, When playing a CD I typically need the volume set at somewhere between 68 and 100 (most are between about 72 and 86, but a track such as Frankie Goes To Hollywood’s The Power Of Love needs to be well into the 90s although the CD layer on the SACD is down in the 80s).
EDIT - Paul has previously made this statement:
This is worrying me for two reasons:
1 - If the SNR is lower at 4V than 2V it doesn’t mean that the base noise (i.e. the noise that’s there at all times regardless of signal) is lower than a Mk 1.
2 - further I’ve no idea what is meant by “a different gain structure via the front panel”. Ted has said that the Mk 1 would need to be a volume setting of 6 more than a Mk 2. So, if I have to set a level on a Mk 1 at 70, I’d only need 64 on a Mk 2, or if a Mk 1 is 100, a Mk 2 would need to be 94. So I don’t understand what a different gain structure is. I have four DSs, three are required at all times and one is a spare. I’d hope to buy three Mk 2s and keep one Mk 1 as a spare which would need a setting of 6 more than a Mk 2.
Yes. I reminded members also. A dozen post above. That statement doesn’t make sense to me ether.
And mkbtam said this:
I can hear some hiss from the tweeters of my Horning Hybrid Eufrodites when there is no music playing on DS DAC Mk2 but the speakers are dead quiet when connected to the Topping D90SE. Therefore, I think DS DAC MK2 has a much higher noise floor although I couldn’t hear the noise when music is playing. On the other hand, I prefer the sound with DS DAC Mk2 because everything is more focused, sounds more real and three dimensional.
Just to clarify a preamp between the DAC and the Amplifier does not filter the noise. It isolates it from the wide open gain of the power amp. Preamps themself can have noise related to tube rush when they employ tubes in their design. The BHK preamp which I use in my system definitely exhibits significantly more tube rush when 6 volt tubes are used as opposed to when the 12 volt tubes are used. A DAC which truly operates in DSD does have high frequency noise that the process creates. Remember that the final stage is actually a video switch that is providing a quad rate DSD output that is passed through a low pass filter and becomes the analog waveform. Those using extremely efficient speakers being driven by an amp in a situation that no preamp is in the chain are going to be accepting that very noise directly into the 20 db or 30 db gain that the power amp provides. My speakers are high efficiency at about 93 db per watt. I never have had any issue with noise when driving them with either the mk 1 or the mk 2 DAC without a preamp. In fact the tube rush caused by the 6 volt tubes in the preamp was far more noticeable than the minute noise from the DAC.
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I guess your B&W matrix 800 speakers are passive so I guess the crossover is filtering/isolating the noise from the poweramps. I too am using BHK250s for mid and treble into professional PMC mid and tweeter drivers.
Further, in the US people have a month’s trial period, we don’t have that in the UK. I’m not going to buy Mk 2s unless they’re no noisier than my Mk 1s because a 3db higher static noise level might be unbearable.
Yes the crossover in the 800 Matrix is passive however it does not filter anything. I hear the tube rush from the preamp when I try 6 volt tubes. The noise issue has been blown out of proportion. Yes I am sure speakers with high sensitivity and under damped peaks in their outputs will definitely make any noise an issue. It is hard when you cannot audition the unit in your system before buying it in your case.
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Thanks for the info but I thought Paul mentioned that DS Mk2 can be used as a preamp directly because of the digital volume control.
I don’t know if these attenuators will impact SQ.
Altering the volume does not alter the fundamental noise floor that’s there all the time. I do use the volume control and the noise floor is well below the music so isn’t an issue whilst listening to music but is noticeable when the music stops.
As you said yourself:
I can hear some hiss from the tweeters of my Horning Hybrid Eufrodites when there is no music playing on DS DAC Mk2 but the speakers are dead quiet when connected to the Topping D90SE