Absolute top tier DAC for standard res Redbook CD

Guido, are you running your Aeris directly to your amps or are you using a preamp in-between? If you tried it both ways, would you share any comments about the relative strengths and weaknesses of each approach?

Sunseekerespana, to your questions:

Is the no gain pre-amp a passive or have valves as a buffer?

The preamp is buffered using solid state devices, very similar to this;
http://www.6moons.com/audioreviews/smcaudio/vre1.html

I use a passive (pot and source switch only). It works really week, but the thing to watch is the DAC has;
1 Enough gain

My current DAC, the Pavane, has an output voltage of 4V, which is more than enough to fully drive the amplifiers.

2 The output impedance is low (less than 500 ohms) If it is higher along with capacitance in your interconnects you may get loss of dynamics and bass roll off.

The buffering reduces output impedance and eliminates loss of bass or dynamics.

3 You can sit the DAC and Passive Pre very close to the Power Amplifier

This is always good practice when possible and particularly with passives.  My ICs from preamp to amplifiers are I to 1.5M.  When I compare my buffered preamp with a passive preamp I own (Goldpoint) I never use longer than 1M ICs.  I also have Endler attenuators, which connect directly to the amplifiers and actually sound pretty good.

I am curious about the variable voltage volume control in DACs like the Overdrive SE/SX, Aeris and now Metrum's Adagio, and whether those have any negative effects (relative to usking a preamp) on things like bass impact, dynamics, staging or other desirable sonic traits.  I was worried about these issues when I went to a zero-gain buffered preamp but it seems to be the best of both worlds with excellent bass and dynamics plus the clarity/purity passives are known for.

Sorry for the infrequent posts. Been crazy and waiting for my ODSX to come to compare the Emm and Empical for a final shootout....

Mitch2 - I have run every single DAC I have tried in this thread direct and never once preferred it. My Burmester preamp is very very good and has always maintained sonic integrity, detail and accuracy while adding a sense of dynamic scale, dimensional depth and realism that vanishes when I run direct. But that's my system. 

Guido has been running his Aeris to his amps direct for quite some time. But that DAC was designed specifically for Rowland Amps to do just that. So everything was fine tuned from output and input gains/impedance/etx to make it work. I think it's an exceptionally unique scenario. 

Hi Mitch2, currently I am running Aeris directly into the Rowland M925 monoblocks. In olden days, I ran the Rowland Criterion linestage between DAC and amps.

　

Which arrangement is "better"? The answer is... It depends... Immediately followed by... I might be persuaded to change my mind, because things are achangin'....

　

First of all, what I observed in the past....

　

* Aeris by itself yielded a subtle amount of greater resolution compared to having Criterion in the chain.

* With Aeris only, there seems to be deep silence from the speakers when music is not playing, vs a very low level of hash when Criterion was in the chain... To perceive the actual noise caused by Criterion, you had to place your ear 6 inches or less from a tweater.

* However, with Criterion in the chain, you would experience a subtly warmer presentation that admittedly is quite intoxicating.

　

Having gone back and forth for several months with the two configurations, I felt I prefered the presentation without Criterion.

　

Having said the above, Rowland has now started to ship the ultra-capacitor based Power Storage Unit (PSU)... Essentially this is an additional full chassis component that can be applied to replace both the external power supply of the Corus linestage (audio circuit identical to the now withdrawn Criterion) as well as the power supply of Aeris... Meaning that a single PSU can power Corus and Aeris simultaneously. Essentially PSU serves pure clean DC 24/7 for compatible line components and takes them completely off the AC grid. There are two banks of ultra-caps inside PSU... While one charges up from the AC line, the other one is offline from the grid, and serves DC to the devices downstream. When the bank of ultra-caps serving devices becomes depleted, the role is switched seamlessly, and the process is repeated... The answer is no, the flipping event is not audibly perceivable.

　

I have not heard PSU yet, but according to all reports I have heard this far the result of PSU on Corus and Aeris might be quite impressive in terms of subtlety, quiet delivery, image and stage, and resolution... I guess the main benefit is being completely off-grid, while not having the problem of reduced dynamic agility caused by the slower transient handling of batteries.

　

So, now I am thinking that a combination of Aeris + Corus + PSU might outperform Aeris alone... Probably even quieter than Aeris, and perhaps with the added grace of having Corus in the audio path.

　

Saluti, Guido

Hi Guido,
Your comments remind me of what I hear.... 

Aeris by itself yielded a subtle amount of greater resolution compared to having Criterion in the chain

reminds me of removing my preamp and using one of my passives, either a Goldpoint passive preamp or Endler attenuators direct to amp, and 

with Criterion in the chain, you would experience a subtly warmer presentation that admittedly is quite intoxicating

which is similar to what I hear through my preamp, which is a no gain, buffered unit with external choke power supply and Shallco discrete resistor volume control constructed using Audio Note tantalum resistors. The main difference from your situation is my preamp doesn't add noise.  

It seems most here end up preferring a preamp in their systems, including those who have used a volume control implemented by changing the reference voltage of the dacs, such as with the ODSE.  One reviewer, Steven Plaskin at AudioStream, slightly preferred having the Ayre KX-R preamp in his system to running the ODSE direct to his Ayre MX-R amps, even with the Final Drive buffers in-line. 

Not using the volume direct  to amps approach would make a jump to the Adagio less attractive, even though it is said to sound better than the Pavane because of the significantly increased reference voltage and doubling of the number of dacs.  I really need to find one to audition to find out for sure how much better it sounds and whether I could live with it direct to my amps.  For now, I will be happy to replace the mac mini I have been listening to for the past couple of weeks with my fully upgraded Antipodes DX, which arrives on Friday, with Roon and the option to use the newly added S/PDIF output instead of USB.  Kudos to Antipodes for supporting existing customers with upgrades and for staying at the forefront of server technology.