Interview with Mark, Sound Engineer

Posted on — by Daniel Robidoux

Mark – Sound Engineer
With your USB cable everything is more “silent”. I can feel the musician’s heart beat, but….
Q: Can I get the dramatic improvement I got from your power cables with your USB cable? What can I expect?

 

Dan – CEO at DR Acoustics
A: We are in 2016 and the audiophile community is just starting to realize the improvements you can get from a USB cable. I am always puzzled when I see a $100K sound system with a $20 USB cable, the argument being that it’s only digital. That is precisely my point. It is digital and so it is dependent on the connection you provide to your DAC.

Clearly, you will not get the same level of improvement from a USB cable as you would from an interconnect or power cord. After all, a USB cable carries “only” digital information. So, as long as it is connected, it will send the right bits, right? Wrong!

The USB protocol uses 2 systems to fix transmission errors.

  • CRC to verify data packet integrity
  • PID which is simply a toggle bit

Improper handling of the toggle bit is a common USB problem that is hard to identify, since the symptoms may not necessarily render a device unusable. You may experience a lower throughput. That is not a problem if you have a mouse or a cam connected. It is, however, a problem if you have a DAC at the receiver end. Of course, the solution to that problem is to resend the bad packet. Not so simple! Retransmitting a data packet causes a resync of the data flow … or in plain English … jitter.

 

Mark
Q: Why retransmit a data packet?

A: Remember that the speed of the USB is relatively high at 500 Mbits/s. That is quite fast to run on two wires. The higher the speed, the more noise is generated on the power and ground planes. Therefore, providing the power and ground planes with special protection makes sense.

That is essentially what the DR Acoustics Digital Marvel does.

Protect the power and ground planes!

 

Mark
Q: So what kind of improvement do I get with the Digital Marvel?

A: Well, improvements vary greatly. A computer’s USB port may have a good power plane. In that case, the improvement may be modest.

However, experience shows that most of the time the computer USB power is very noisy.

“I see a business case for a computer with low-noise USB Power and Ground planes. Oops … that already exists. It’s called a network player”  

The Digital Marvel cleans the planes therefore improving the clock S/N ratio.  

This means that the Marvel will vastly improve the power and ground planes on a “bad computer” and do nothing on a “good” computer.

Unfortunately, at the end of the day, the only logical solution is to test the system with and without the Marvel cable. Case in point, two of my customers found improvements using the Marvel on state-of-the-art network players.

Thanks, Mark. Great hearing from you.

DR