[davidc2]

I want to use again my Graham Slee Novo headphone amp even though I have the DacMagic Plus (which has a headphone socket).  My pc soundcard passes a digital signal to the DMPlus as does a Cambridge Audio CD player.  What I would like to do is use the Digital-Out of the DMPlus into the Digital- In on the DM (not Plus) and then take a Phono unbalanced out of the DM and into the Novo.  The circuit would look like this:
 

The DMPlus manual says that the digital out is just the incoming digital dignal untreated, so in my suggested set up it would be the DM (not Plus) that would be converting the signal and sending the resulting analogue signal on to the Novo headphone amp. Cambridge Audio have said that this will not work - and they should know.  But before I try it I just wondered if anyone here could explain to me why it would not work.
 
Thanks.

 

[project86]

Just one question question - why? It seems you could accomplish everything you need with just one of the Cambridge devices in the chain. Unless I'm missing something, there is no reason why you need both. In your diagram, the DM+ is basically being wasted, since the signal is merely passing through untreated.
 
That said, I can't think of a reason why it wouldn't work. Are you starting with an SPDIF signal from your soundcard? If you were using USB, I could see that perhaps not working if the DM+ doesn't transcode USB signals to SPDIF (I don't know if it does, but likely not). 
 

 

[davidc2]

I want to do it because I have dedicated headphone amp that I like very much.  I will probably use the DMPlus headphone amp too but the sound so far is a little brittle.  There are two digital sources - SPDIF from my Asus Essence STX to the DMPlus and a Toslink from a CA Azur 650c CD player to the DMPlus.  I am driving two Genelec active speakers and particularly wanted the Volume control on the DMPlus - I had been using a Level Pilot control but this developed crackling often and also provided an uneven volume balance at low levels. 
 
I have tried out the configuration with mixed results.  Basically the CD player can be heard perfectly through the DM but digital signal from the Asus sound card cannot.  I don't understand why.  Switching the digital signal source on the DMPlus does not seem to also steer the different source to the digital out socket.  From the user manual, I thought that the DMPlus would just pass on whatever digital source was selected - but apparently not.  I can't see how the problem is with the DM - it surely just works with whatever digital signal is passed on to it. 
 
Worth trying - halfway there. 

 

[project86]

Quote:

I want to do it because I have dedicated headphone amp that I like very much.  I will probably use the DMPlus headphone amp too but the sound so far is a little brittle.  There are two digital sources - SPDIF from my Asus Essence STX to the DMPlus and a Toslink from a CA Azur 650c CD player to the DMPlus.  I am driving two Genelec active speakers and particularly wanted the Volume control on the DMPlus - I had been using a Level Pilot control but this developed crackling often and also provided an uneven volume balance at low levels. 
 
I have tried out the configuration with mixed results.  Basically the CD player can be heard perfectly through the DM but digital signal from the Asus sound card cannot.  I don't understand why.  Switching the digital signal source on the DMPlus does not seem to also steer the different source to the digital out socket.  From the user manual, I thought that the DMPlus would just pass on whatever digital source was selected - but apparently not.  I can't see how the problem is with the DM - it surely just works with whatever digital signal is passed on to it. 
 
Worth trying - halfway there. 

I see. So you basically need two sets of outputs - one for your speakers, and one for your headphone amp. I still think this can be accomplished through some other method rather than using the DACs in piggyback mode. 
 
Do the speakers have XLR inputs? Many/most Genelecs do, but some (like the 6010A) do not. If they do, then simply run XLR to the speakers and RCA to the Novo. If they don't, you could pick up some cheap XLR to RCA adapters/cables and then run RCA to each device. 
 
Another option is just splitting the signal at the RCA output of the DM+. I've used these before and they work fine. As long as you switch off the device not being used it should not degrade the signal. 
 

 

[davidc2]

Yes, I'm using XLRs with the Genelecs.  I have 8020As with a 7050B subwoofer.  I love them.
 
The problem with your approach is that when you feed the Phono outs on the DMPlus to the headphone amp you have to have the volume on the DMPlus at max in order to hear it at a reasonable level on the headphones.  This obviously defeats the purpose of having headphones.  You can of course turn down the Genelecs using the volume control on the front of each speaker cabinet but this would be a pia. It's just weird that the separate digital sources on the DMPlus are not individually routed to a Digital Out on the DMPlus when you change the source setting.  I don't know why the signal from the CD player gets through but not the sgnal from the PC's sound card.

 

[project86]

I get it - the DM+ is probably only giving a reasonably powerful signal when it is wide open on the volume knob. Maybe a different amp would work better, having a more sensitive input - but it really shouldn't have to. That's a bit disappointing on the part of the DM+.
 
There is a way to do it without controlling volume from the Genelecs: You'd run the DM+ at full volume when using headphones, then turn it way down whenever you wanted to use the speakers. That's like an accident waiting to happen!
 
I'm stumped too as far as why one signal makes it through and the other doesn't. Are you using any sort of software upsampling on your computer? I'm sure the DM+ is able to accept hi-res signals via SPDIF but maybe that somehow interferes with the passthrough feature. That's really the only thing that could be different between the CD player and the soundcard. 
 
Have you tried using coaxial from the CD player to the DM+, to see if that makes it through? Maybe it somehow only works with toslink. 

 

[davidc2]

Thanks for pursuing this with me.  You understand the situation with using the phonos exactly -  To get decent level out of the headphone amp you have to have a load of level on the speakers.  That's no good. 
 
My digital connections are all Coax - soundcard to DMPlus and CD to DMPlus and DMPlus to DM.  You can use two digital inputs on the DMPlus and DM.  You can also use 2 digital outputs simultaneously.  Cambridge Audio tech support compound the mystery:
 

 
So "...it will not work as you think you [it] will.." seems about as much explanation as I'm going to get.
 
I could try going into the DM first and taking a phono out to the headphone amp - that should provide enough level for the headphones.  But it almost certainly won't solve the digital source problem - ie the DM also probably won't let you listen to both digital sources (like the DMPlus).  Cambridge Audio implicitly seem to rule that option out.
 
So I'm stumped I think.
 

 

[project86]

I notice that the DM+ has an "optional digital preamp mode" listed. Does that refer to an extra part that you need to purchase, or a mode that can be selected/disabled? If it IS an add on, does your unit have it?
 
Earlier you said you were using toslink from the CD player to the DM+. Since that seems to pass through, I figured maybe you could try a coaxial digital connection instead, to see if that also passed through from CDP to DM+. If so, then we will have isolated the soundcard as being somehow to blame. If you can - try that and we will go from there. 

 

[davidc2]

The Digital Preamp mode ios the default one - that I use:
 

I don't want to use the other mode because it will not give me volume control over my Genelecs.
 
I get the same result if I feed the DM from the DMPlus with a Coax from the CD player.  I can hear it but not the other source.  But I don't think it's a probleem with the soundcard - it transfers a digital signal fine to the DMPlus and it worked fine with the DM before the DMPlus.  It is the DMPlus that seems to be the problem - it will only transfer one digital source to whatever it's connected to - or at least to a DM.
 
Hmm.
 
 

 

[davidc2]

Update - I have the DMPlus to DM to Novo configuration working.  I don't know why.  I must go over the settings again.  But great news for me.

 

[project86]

Interesting. I still think it seems like there should be a better way to do this - you don't use the speakers and headphones at the exact same time, right? But it is good that it suddenly started working. 
 
On another note, you could probably sell both Cambridge units and get a single box solution that would get the job done. Maybe even something with a great built in headphone amp so you wouldn't need the Novo in the chain. But that's down the road I guess - for now you are good (though we don't quite know why yet).

 

[mdehaan]

 
Hey David,
 
Can you tell me the differences between the integrated headamp of the DacMagic Plus and the Graham Slee Novo.
I have the DacMagic Plus and think the integrated headamp sucks.
What is the diference in sound when playing music with the Graham Slee Novo attached trough the DacMagic Plus?
What source are you using?
 
Sound stage, Dynamics, Attack, Lows, Mids, Highs, Better at low volumes and everything you can tell me.
 
I would realy appreciate it if you would take the time to write it down
Thanx in advace!
 
Kind Regards, Marten

 

[davidc2]

OK.
 
Sources -
 
- SPDIF coax from pc (through Asus Essence STX) to DMPlus playing an HDTracks 96/24 FLAC of Steely Dan's 'Babylon Sisters' from "Gaucho" using HD650s.
- Cambridge Audio 650C CD player into DMPlus using Toslink playing 'Oh La La' from Jeff Lorber's 'Flip Side' album 
 
DMPlus>DM>Novo>HD650
 
I may be at risk here of trying to count how many angels can dance on the head of a pin - the difference between the NOVO and DMPlus is not great - I could live with either.  With that caveat, what do I notice?  The two H-amps treat bass a little differently.  There seems to be more low bass in the Novo and its upper mid bass is more articulate - what I mean is that, for example, you can hear the slap of what is obviously a leather beater on the bass drum pedal clearly on the Novo where it is less clear on the DMPlus.  I would say the mid range is more pronounced on the Novo (which I like).  I think the high end is a little sweeter on the Novo - the DMPlus's treble can be a little hot.  On the Novo hihats ting more than fry which I prefer. 
 
The Novo brings a little more to the party at low volume. 
 
Neither has a particularly wide or noticeably narrow stereo stage - the Novo is perhaps a bit more spacious - noticeable with string arrangements.  Overall, the Novo probably offers a more weighty and articulate presentation.  The gaps between notes - like piano notes - are clearer on the Novo I think.  This makes the music more involving.
 
Reading through my comments it looks like the Novo is obviously superior - I don't think that.  I would be happy to listen to the DMPlus headphone output - but the Novo seems to me a little more more musical.
 
David
 

 

[muz640]

You could have simplified a bit more and bought an Asus essence One instead of the Dacmagic Plus, great little headphone amp on the Asus. Both Dacs work great into actives however, different character between the two but both very good. 

 

[davidc2]

Yes, I could have tried the Essence One instead of the DMPlus.  I'm sure it's very capable.  I just couldn't live with the bright blue light round the power button.  I like the STX card and I'm sure the Essence One is very good, though I don't like its looks at all.