Rowland DAC

[Gregadd]

http://www.hpsoundings.com/2013/01/rowland-aeris-dac/

 

[AMP]

This one has always intrigued me and I've been a long-time fan of Rowland's products (and continually frustrated at the lack of rhyme or reason to the product line).

I'm currently running a Wadia 931/922 digital setup and am seriously considering going to one of the "new" DACs on the market which may not be an all-out assault on the state of the art, but appear to be delivering excellent results in smaller and cheaper packages. I've been planning to look at the Bricasti M1 and I keep coming back to the Aeris as well.

I'd be interested to hear from other members who have had some experience with it.

 

[Gregadd]

I've been intrigued by HD Tracks Hi Rez downloads whose quality is apparent across my computer.

 

[GuidoCorona]

I loved Art Tedeschi's article on Aries. While I am unfortunately not using an Aeris, I concur with his findings. If anyone is interested in further Aries technical detail, the Jeffrowland.com Knowledge Base contains 25 short articles on Aeris, covering engineering/design, features, and photos. See:

http://jeffrowlandgroup.com/kb/search.php?q=Aeris&page=1

http://jeffrowlandgroup.com/kb/categories.php?categoryid=205

 

[FredTam]

Jeff Rowland Aeris DAC

This one has always intrigued me and I've been a long-time fan of Rowland's products (and continually frustrated at the lack of rhyme or reason to the product line).

I'm currently running a Wadia 931/922 digital setup and am seriously considering going to one of the "new" DACs on the market which may not be an all-out assault on the state of the art, but appear to be delivering excellent results in smaller and cheaper packages. I've been planning to look at the Bricasti M1 and I keep coming back to the Aeris as well.

I'd be interested to hear from other members who have had some experience with it.

I have been using Aeris since November 2011, exactly one year after I acquired Wilson Audio Sophia 3, I am feeding the DAC directly to the power amp - Modwright KWA-100SE with Cardas Clear balanced interconnect. I was comparing this with DCS Debussy DAC. In my system, I picked Jeff Rowland because DCS is more Hi Fi, Jeff Rowland is more organic and musical. I use my Accuphase DP-77 as transport, the red book CD sound better than the SACD from DP-77. I would say the sound is more enjoyable and involving. Using Bryston BDP-1 to play wav file from HD tracks has been amazing. The sound stage is reasonably wide and the density of musical data is superb. I would choose the word palpability and I love the sonic picture allows me to sense the sound of different instruments and the distance between them without being too analytical. If possible, I would love to add pre-amp but I am struggling if I should get the Corus pre-amp or I should get the 625 power amp. I did a direct comparison last July when I was in Hong Kong in Jeff Rowland's showroom with and without Corus pre-amp with Avalon speakers (forgot the model), the sound is a touch better with Corus but I just don't know what it is base on my memory and I will need to go back again by end February to re-visit that.
One recommendation, must use balanced interconnect as I was using Siltech RCA cable with unbearable hum, changing to Cardas Clear balanced leads me to "the art of silence".
That's all I can say for the time being.

 

[Elberoth]

Does it have a variable out ?

 

[FredTam]

May I know what variable out is ?

 

[Elberoth]

Variable output = volume control.

 

[FredTam]

Variable output = volume control.

It does as per my prior e-mail, I am driving that directly with Modwright KWA-100SE.
To be honest, I do not like the volume control from the DAC and I believe the gain is way too high and that's the reason why I am exploring between Jeff Rowland Corus or Spectral SMC33-SS series 2.

 

[GuidoCorona]

Aeris has variable output, with gain in 1dB increments, I believe. The device also has balanced out, and can be connected to a pre or directly to an amp. More information at:

http://jeffrowlandgroup.com/kb/questions.php?questionid=581

and

http://jeffrowlandgroup.com/kb/categories.php?categoryid=205

 

[Old Listener]

http://www.hpsoundings.com/2013/01/rowland-aeris-dac/

One paragraph caught my eye.

"Various methods of encoding and decoding digital music have come and gone, but these small steps forward (with occasional steps backward) have ultimately resulted in reasonably decent sounding products. Many of these digital audio improvements arose from massive R&D investments in computer technology; had it not been for the constant advances in IC chip technology, our digital devices would surely sound poorer than they do today. (Evidence: today’s $300 Digital-Analog-Convertors have significantly better sound than the $30,000 DAC’s of yesteryear.) Recently, the market has become flooded with DAC’s providing great results– signaling a new age in the sound of digital ."

These might be fightin' words to someone who is still attached to his expensive DAC of a few years ago. The paragraph might also be controversial in asserting that advances in DACs and other chips by non-audiophile companies might play an important role in sound quality.

Bill

 

[Elberoth]

(...)To be honest, I do not like the volume control from the DAC and I believe the gain is way too high(...)

That is possible. The DAC has an unussualy high output voltage (7V), meaning that unless you use an amp with very low gain and/or low sensitivity speakers, you will need a preamp.

 

[microstrip]

One paragraph (of http://www.hpsoundings.com/2013/01/rowland-aeris-dac/) caught my eye.

"Various methods of encoding and decoding digital music have come and gone, but these small steps forward (with occasional steps backward) have ultimately resulted in reasonably decent sounding products. Many of these digital audio improvements arose from massive R&D investments in computer technology; had it not been for the constant advances in IC chip technology, our digital devices would surely sound poorer than they do today. (Evidence: today’s $300 Digital-Analog-Convertors have significantly better sound than the $30,000 DAC’s of yesteryear.) Recently, the market has become flooded with DAC’s providing great results– signaling a new age in the sound of digital "

The usual vague evidences, that no one can say that are right or wrong in conscience. Yesteryear in digital can mean anything, and I would like if the author could put some names in the $300 and $30000 years.

 

[microstrip]

That is possible. The DAC has an unussualy high output voltage (7V), meaning that unless you use an amp with very low gain and/or low sensitivity speakers, you will need a preamp.

Let us hope it has some kind of analog attenuator. Many IC based precision attenuators used immediately at the input of preamplifiers will not be happy with such an high output voltage.

 

[Elberoth]

I think you can overload many preamps with this kind of voltage.

 

[AMP]

To circle back around on the output voltage discussion.

The Aeris I have for eval came with a printed manual which better explains the operation of the volume control. It's easiest to look at it in terms of 3 ranges.

From 0 to -32db the control is not harming the signal in any way (no information is being lost).
Below -32db you're outside of the critical listening range (which suggests that information is being lost).

The interesting thing is that there's a third range from 0 to +20db which is accomplished through multiplication of the digital signal. Per the manual this range is useful for digital sources with extremely low output levels or when you simply want to "rock out" without being concerned about the potential for clipping of the digital signal (Hey, this one goes to 11!)

Of course, I don't have the manual in front of me but if I recall correctly there is about 60db of adjustment in the first two ranges and with the addition of the overdrive there's a total range of approximately 80db (again, my numbers may be wrong and I'll check and edit this evening).

Per the manual the first two ranges are accomplished by modification of the reference voltage to the DAC chip which, per the manual, means that the volume adjustment happens in neither the digital nor analog domains. In other words, there's no analog attenuator and no bits are discarded.

If I'm understanding this correctly then the output voltage maxes out at 7V when the control is at the +20db level through signal multiplication, but would be much lower if the control is set at 0db. In other words, when connecting to a preamp using the recommended setting of 0 on the volume control the output voltage is more in line with typical line level components. I can verify this as with my Wadia output voltage set at 3.3V I needed to add a negative offset of about 2 - 3db in the preamp for the Aeris input in order to match levels.

 

[FredTam]

My Aeris DAC did not come with any instruction or manual at all and I did e-mail request but did not get any reply at all and it's not being posted on their website either. My problem is it's not way for me to gauge what db I am at as it only show 2 lights and it only show the following, if you tune volume all the down, only the light at left lights up but not the right, when you push the volume up and see the left light dim gradually and the right side lights up gradually and naturally if you push the volume all the way up, only the right side lights up and the left light will be off. That why I feel not comfortable using the DAC directly with my power amp.

 

[GuidoCorona]

Fred, what amp are you using with Aeris? what is its input impedance, gain, power, current? G.

 

[FredTam]

Dear Guido,
I am using ModWright KWA-100SE but will change to Spectral DMC30SS + DMA260 power later this year.
I have more confident with a pre-amp since I am still spinning vinyl.

 

[AMP]

My problem is it's not way for me to gauge what db I am at as it only show 2 lights and it only show the following, if you tune volume all the down, only the light at left lights up but not the right, when you push the volume up and see the left light dim gradually and the right side lights up gradually and naturally if you push the volume all the way up, only the right side lights up and the left light will be off. That why I feel not comfortable using the DAC directly with my power amp.

The volume control is not intuitive, but I think I've figured it out. When you turn the volume all the way down the left LED should flash quickly. As you increase the volume level it will become solid at one point. This is the the -32db level and the start of the critical listening range. As you increase the volume the left LED will dim and the right will get brighter. This will continue to the point where the right LED becomes solid and eventually starts to flash. The last step of the volume control where the LED is solid is the 0db level. Past this point, where the right LED is flashing, is the overdrive mode. The range in which the two LEDs are lit solid at different brightness is the critical listening range.

Granted, I would prefer a more intuitive and direct display, but once it figured it out I could see where it would be a workable.

if you are using a preamp then you want to increase the volume until the right LED starts flashing and then back it off one step so that the LED is solid. This gets you the full signal without going into the overdrive range where the digital signal is multiplied.