Audio grade USB cables


I've had issues with this for years, trying to wrap my head around digital bits being lost, etc. Anyway, the debate in my head is settled, the USB cable does in fact make a big difference to your sound. But not because the cable is special or not special, it's the computer. The 5 volt power feed from the computer's USB output port literally infects sensitive audio electronics - USB DAC's specifically.

Some expensive USB cable designs may in fact improve this problem but they don't solve the problem. The problem is the dirty 5 volt power feed.

So why not just eliminate the 5 volt power feed? I've heard of people simply cutting the power lead in the USB cable. That may work for some DAC's but the majority require 5 volt power to function. And USB DAC headphone amps are often powered by USB alone - no wall plug. So you can't just cut the line in most cases.

What you can do is replace the dirty 5 volt power lead with a clean source of power - and by clean I mean any wall outlet is going to be clean by comparison to your computer's USB output port. Why? Because your computer has literally millions of circuits that are making noise and that noise is transmitted down the 5 volt power lead!

And that dirty power may mess up the data bits too, by interfering with the data lines inside the USB cable. So it's a problem with many dimensions.

I created a new product called USB Disruptor to solve this problem. I've advertised on Audiogon and have a unit for sale on Audiogon. It's a simple idea, disrupt the computer's dirty power and replace with an independent source.

The units are hand made by me with 7 welds per unit. I use silver bearing solder and the best parts available - though you don't have to go overboard with digital because it really is just bits - so long as you've dealt with the dirty 5 volt power issue!

The improvement to the sound can be dramatic depending on your setup. With my headphone setup it's very easy to pick out the differences, and these have been replicated with several test subjects.

With my reference system I've already spent over $1200 on a USB isolation product that is supposed to clean up the power and more, but sure enough it's improved with USB Disruptor. For example, last night I was listening to The Doors debut album - has light my fire and break on through - and it's a high rez from HD Tracks - and this time, with USB Disruptor, it sounds like Jim is totally separate from the band. He's hovering 3 feet above the center of my speakers and I can hear him tapping his hand on his leg maybe, something I've never heard before.

Dirty 5 volt USB power clouds the music, but in a way that is evenly spread across the frequency spectrum, so it's hard to consciously isolate a specific problem, it seems to sound normal. It's like a shade is put over your music. You can still enjoy but you're not getting the clearest and most lucid picture. When you use USB Disruptor the shade is removed and you can hear the quiet spaces between musical notes.

You will only appreciate the difference when you hear it. Don't all of us audiophiles (sometimes audiophools) swear our system is just perfect and then we add something new and realize we were still missing something?

That happens to me a lot, and I was surprised USB Disruptor functioned as well as it did in my reference setup.

It's logical though: if your computer is connected to your audio system by means of a USB cable then interference laden 5 volt power from the computer is getting into your DAC and other audio electronics. It's going to be very, very hard to stop that dirty power from affecting your music.

The best way to solve this problem is to completely disrupt the power from the computer's USB port. And that's what USB Disruptor accomplishes - it's simple, effective, and affordable.

I have no doubt that USB DAC's of many flavors have been sold off or given away by many of our audiophile brothers because they just sounded crappy - too shrill at times, flat stereo image, etc. But it wasn't the DAC - it was the dirty USB power. This is hard to believe but it's true. And I know it's true because I've heard the results.

Have any of you guys tried cutting the 5 volt power lead in the USB cable? Did it work for your DAC? It won't work for most, but maybe some.

Anyone else try other products that have helped? I know USB Regen is similar, they claim to cut the power too but it's still actually connected, not exactly the same as USB Disruptor. Of course, USB Disruptor is less than half the cost of USB Regen.

And that Audioquest jitterbug, that is more like a filter. I don't want to filter anything for fear I'll lose precious signal. Anyone use those?

The fact is there's a problem with USB. These products all tell us that. But don't make any mistake, it's the dirty power from the 5 volt output that's the biggest issue, and that's the problem USB Disruptor solves.
robpriore
Shielding will not reduce CM noise.. USB is differential, so the ground wire is not involved in the data transmission, however it does set the reference for the source qnd receiver.. If there are any ground loops in the system, CM noise will be present.. This can be measured with a scope, but the measurement needs to be differential, using differential probe with no earth ground affecting the measurement.
My engineering advisor says "The whole point of differential communications schemes is immunity to common-mode noise."

He also says you're right about ground loops, but that is "one of the most tangled webs you can weave in electrical engineering."

It's ironic because all of this back and forth is well and good but it's only half the story.  If you don't listen then you can't really understand what it's doing. 

In this case, the observations back the theory that unwanted noise from USB vBus affects the time domain.  That in turn flattens the sound stage - makes sense that it would - and throws off spatial directions just enough to cause voices to bleed and shrill and harsh tones at times.
@ robpriore: why has the USB Disruptor tripled in price from $49 to $149 in the 4 years since you started this topic?

Also in what way does this product work any different than simply putting a piece of tape over the 5V pin if your DAC doesn’t need the 5V supply ?