Absolute top tier DAC for standard res Redbook CD

Hi Agear, a few posts ago, you brought up an interesting technical point... Electrical and mechanical grounding. I looked this up in the Rowland Knowledge base, and here is what I found in the Aeris section....

Aeris uses very small surface mount devices (SMD). According to one article, a benefit of SMD is "allowing these components to be located as close as possible to corresponding ground planes". See:
http://jeffrowlandgroup.com/kb/questions.php?questionid=622

More on Aeris grounding... "In the Aeris 6-layer PCB, two complete layers are dedicated to ground. The clock signal is isolated from the signal path by these two grounding layers. Two layers are dedicated to power distribution, and two layers are dedicated to signal distribution. As a result, the clock signal cannot be contaminated by the audio signal." ... There is more on electric grounding and 6-layer PCB design at:
http://jeffrowlandgroup.com/kb/questions.php?questionid=621

On mechanical isolation of the power supplies... "Aeris is powered by two separate low noise, passive power factor corrected, switch mode power supplies (SMPS) – one for analog and one for digital. Both are housed in a single machined external enclosure for maximum mechanical and EMI/RFI isolation." See:
http://jeffrowlandgroup.com/kb/questions.php?questionid=619

In general, Aeris circuit sections are buried inside isolated pockets carved in the aluminum ingot of the main chassis.... But this is nothing terribly new... Rowland has used monolythic chassis for mechanical grounding/isolation for a couple of decades.

Other manufacturers may have used totally different techniques... Of course, in the end, it really does not matter... What is important is whether we emotionally drawn by the sound of a component or we are not.

G.

"Aeris is powered by two separate low noise, passive power factor corrected, switch mode power supplies (SMPS) – one for analog and one for digital."

Actually, the Overdrive SE uses three SMPS, one for digital and two for analog. Each has a Hynes-type linear regulator on the output. All of these are housed in a separate chassis. Very similar to Aeris I think, except for one important distinction; the Hynes regulators. The power and ground return techniques are very similar too.

Another key difference in the Overdrive SE is that any trace in the analog section that would be over about 3/4" long is replaced with an externally routed pure silver cotton insulated twisted-pair cable. FR4 glass-epoxy is the enemy of good analog signals. Dielectric absorption is the issue.

Steve N.
Empirical Audio

"FR4 glass-epoxy is the enemy of good analog signals. Dielectric absorption is the issue."

Most interesting tidbit of information Steve. No more than 3/4" long. Wow, I have some modding to do:-)

Granny - I learned this lesson from modding Mark Levinson gear, which is very dark sounding. I jumpered most of the long traces with silver wire and it opened up and became airy. No darkness. I don't mod anymore, but I learned a lot from 10 years of it.

Steve N.
Empirical Audio

Hi Agear, a few posts ago, you brought up an interesting technical point... Electrical and mechanical grounding. I looked this up in the Rowland Knowledge base, and here is what I found in the Aeris section....

Guido, I read through that site and was duly impressed by the meticulous detail internally in addition to the chassis work. Most dacs fall short in this area. I am sure its part of the reason why the Aeris sounds good.