USB Extender Solves Cable Length Limitation

[Charles Hansen]

One of the limitations of USB is that its cable length is effectively limited to 3 meters (regardless of what the cable manufactures may claim). For most people this is not an issue, but for some it is.

 

One solution is to use an ethernet DAC, such as the Linn that Art Dudley gave a positive review to in a recent Stereophile. He also noted that the music player software choices can be restrictive and/or confusing.

 

We have recently tested a USB extender that works well up to 192 kHz, even with asynchronous USB transmission (which requires duplex operation with signals going both ways). They claim 100 meters, but the longest CAT5 cable we had was 100 feet. It worked fine at that length.

 

It is moderately expensive at $325, but a $50 USB extender we tested did not work at all. This product could be a good option for many people. It is available through Amazon.

 

http://www.icron.com/products/usb_new/usb20_ranger_2101_2104.php

 

[Gregor Samsa]

This works just fine with my...QB-9.

 

http://www.monoprice.com/products/product.asp?c_id=103&cp_id=10303&cs_id=1030312&p_id=2779&seq=1&format=2

 

Oh, and I'd avoid that Linn thing too. QB-9 is much better. For the record, Dudley has cast aspersions on Randy Newman's "Good Old Boys", Richard Thompson's "Shoot Out The Lights", the entire career of Mike Bloomfield, and, of all people, Fred Newman - the sound effects guy from "A Prairie Home Companion". I believe it was none other than J.Gordon Holt who referred to Dudley as a "tin-ear".

 

[Charles Hansen]

Hello Gregor,

 

Thanks for the report. That certainly is a much less expensive option. The link you gave was to a 5 meter extender. They make longer ones up to 82 feet, still for a very low cost.

 

Have you tried any of the longer ones? With an asynchronous DAC there is a limit as to how far you can go, simply due to the round trip transit time of the audio signal going to the DAC and the feedback control signal going back to the computer.

 

With USB 2.0 (required for going beyond 96 kHz) this puts a limit of around 15 or 20 feet of cable. The Icron has some patents that I haven't looked up, but suspect that it has some buffering at one or both ends to avoid this limitation.

 

Have you tried your extender at 192 kHz?

 

Thanks for your comments,

Charles Hansen

Ayre Acoustics, Inc.

 

[Gregor Samsa]

Works like a champ with 192 kHz. The Monoprice blurb says their cable is buffered too. I haven't tried any of the longer ones.

 

[Charles Hansen]

Thanks for the update. These things are practically free, even the longer ones. 5 meters can work with a regular passive cable if the cable is good and the USB transmitter chip in the computer is also good. So I'll want to try a long one to see how it behaves before we recommend it.

 

Thanks very much for the tip -- the price is certainly right!

 

[Quest]

I actually use a 15m ethernet cable with a $10 extender from China.. can't work with usb 2.0 but it is fine for 1.1. I use it just for my keyboard so this is a non-issue for me.

 

Am sure we'll be able to find one that works for USB 2.0 if only we run through all the products available.. so far the ones I have heard works tend to be more expensive.

 

For instance, I have heard Opticis is reliable as well. Using fibre optics instead of ethernet cable.. I do know some people have ever used this before just to get 'galvanic isolation' from their PC.

http://www.opticis.com/english/02_product/product03.htm?PHPSESSID=82c59d17a5ea3e1a8de115623c5b315f

 

[Jim Smith]

There are times on client voicing projects that I need a bit longer cable than my Transparent 2m.

 

Didn't actually care for the 5M Transparent version.

 

At this price - for a total of 7M, can't afford NOT to try it.

 

 

 

[agentsmith]

Hi Charles and others, I have actually used a cheapo Belkin 4.8m USB extension cable connected via the freebie USB printer cable that came free with the dCS Debussy DAC. So the combined distance would be slightly more than 5m.

 

I have had no problem with syncing nor any clicking with this setup. Do you think the sound quality would be compromised in any way as opposed to using a short "built for audio" cable? Or is it just a matter of sound or no sound?

 

I know there are differing opinions about whether USB cables make any *significant* difference with async DAC, just curious on what the experts think.

 

[Jim Smith]

My 5M transparent worked, just not as well as the 2M.

 

This was on 96 kHz files, however.

 

So the extender doesn't have to just work, I hope to hear it make no difference when added to the 2M Transparent.

 

[Charles Hansen]

1) The Opticis fiber-optic cables are top-quality products. They make a wide variety of cables, including HDMI. But for some reason, their USB cables are limited to USB 1.1.

 

2) The I have heard is that going beyond 3 meters with any brand of cable results in noticeably degraded sonics. Hence Jim Smith's observations. This may or may not be dependent on the brand of DAC and/or type of transmission protocol used. Test so far have been with asynchronous DACs.

 

3) Stringing two cables together may or may not work, depending on the DAC and the computer and the cables, but it almost certainly won't provide the optimal sound quality.

 

4) We compared a 5 meter brand-name cable against the Icron extender with a 1 meter brand-name cable and the Icron setup was obviously better sounding. (Which ties in with point # 2).

 

[Audio_ELF]

agentsmith

 

Have you tried emailing dCS to get their thoughts? When I've emailed then they'd been very responsive to my question.

 

Also, as you use a laptop, can you get to borrow (or buy on sale and return) an audiophile 1m cable then you can easily compare.

 

Eloise

 

[ferenc]

Works extremely well, works even with M2Tech Young DAC up to 354.8 kHz / 24 bit.

 

Icron has some patents on it, does not require software drivers, works like charm with all of my Macs. One of the benefits of the technology, that the Cat5/USB2 converter dongles / connectors have small impuls transformers, so make the connection between the computer and the receiving end isolated somehow, ground loop free. The other benefits that you do not have to use the computer to power the chain, there is an external power supply unit for the receiver dongle, 5V 1.5A, so you can even use a battery to power the receiver dongle which than can power the USB - SPDIF interface like HiFace for example. All in all, very practical, relieable connection and I even hear it a bit smoother, quieter than the directly conncted HiFace. Do not ask the reason why.

 

This way you can put the computer anywhere you want, you need to keep only the small receiver dongle (usb hub in case of the Icron 2204) and its power supply in the high-end audio system, computer can be another room and remote controlled by an iPhone/iPad.

 

[Jim Smith]

To put a fine point on your observations, are you saying that the best 1M USB cable you've tried is improved upon with the substitution of this extender?

 

[Charles Hansen]

The Icron is two parts connected by a long CAT 5 cable. It has a 1 foot USB cable built into the computer end. The far end has a USB socket that requires another USB cable to connect to the DAC and a wall wart to provide 5 volt power.

 

A friend was using a well-respected 5 meter cable. We swapped that out for the Icron with a 1 meter cable between the far end and the DAC. The improvement was obvious.

 

In a separate test, it did not sound better than a 1 meter direct connection:

 

http://www.audioasylum.com/forums/pcaudio/messages/8/87058.html

 

But if you have to separate the two devices, the Icron is the best solution we have tested. We will test some of the other suggestions made to us on this thread.

 

The word on the street is that going beyond 3 meters with any brand of USB cable will cause sonic problems, and this is consistent with the test described above. All of the tests that I know of were done with asynchronous USB DACs. It is possible that adaptive mode DACs would behave differently.

 

[Jim Smith]

I wanted it to be be better in some ways, but that's a chunka change plus another piece or two, plus cables, to carry on the plane.

 

But I probably won't be surprised if we eventually get some interesting news from a variant of this concept.

 

[sandyk]

It could be an interesting exercise to replace the +5V wallwart with a good +5V Linear PSU ?

SandyK

 

[Charles Hansen]

Read the link to the other site. We tried it with a battery power supply with virtually no difference, but that may be due more to the DAC than the Icron.

 

[Jim Smith]

I received the Monoprice 5M USB extender, and added it to my 2M Transparent Cable.

 

When the MBP powered up and PM/iTunes were opened, the QB-9 immediately recognized the 24/176 signal I selected. The USB 2.0 handshake is solid, as it's played for over three hours.

 

I've left it to run a bit while I work on another project.

 

So we know that USB 2.0 at least works with a virtual 23'/7M USB cable from Monoprice at 24/176.

 

So how does it sound?

 

Will listen over the weekend.

 

[Charles Hansen]

Wow, that is great news about the Monoprice repeater! Those things are practically free. Hopefully it will sound good. We have their longest one on order and will provide some feedback on that one soon. Thanks for the update, and I'm looking forward to hearing about how the 5 meter version affects the sound quality.

 

[Nikola Krivorov]

Hi guys,

I was wondering what happened with the expereiments-any new conclusions? This is something that is of great importance to me as I am planning to use a mac mini as a source and getting it away from the system and being able to use wired keyboard and muse will be a great advantage. TIA

 

[Charles Hansen]

We bought the longest one they make. I think it is 82' long. It is very inexpensive. We have done some preliminary testing, and the good news is that it works all the way up to 192 kHz with asynchronous USB (traffic both ways). We haven't yet done a listening test to see how it affects the sound. We'll keep you posted.

 

[Jim Smith]

The 25' Monoprice repeater actually worked at 176 kHz, for hours on end, meaning that it passed the signal with no drop-outs or other issues.

 

I wanted it to work to be able to carry it on RoomPlay sessions.

 

Alas, it wasn't equal to my 2M Transparent cable alone. Not bad, but not good enough - IMO - to use in voicing sessions.

 

If having pretty good sound is good enough in order to get the length you need, it's a good choice, not to mention the attractive price point.

 

 

 

 

[Nikola Krivorov]

Your posts are much appreciated, if there is anything new please keep us posted. TIA

 

[Charles Hansen]

Even though our Monoprice extender was significantly longer than the one that Jim Smith tested, we had a similar reaction. There was a slight, but noticeable loss of sound quality.

 

Both the Monoprice and Icron sounded similar to each other, so clearly the Monoprice is a much better deal. And if you have to go beyond 3 meters, then it's not a horrible solution.

 

Our reaction was that the change in sound is similar to what you get with a brand-new, unbroken-in cable. So we are going to connect both of them together and run a signal through them for a week or two and see if the sound improves at all.

 

One difference between the units is that the Monoprice is a single assembly with the ends permanently connected. In contrast the Icron is two separate pieces (with a wall-wart for the receiver) and you have to supply your own CAT 5/6 cable. Currently we just have some cheap bulk CAT 5 cable that we terminate ourselves. We have not yet tested the idea of using different CAT 5 cables to see how that affects the sound...

 

[bottlerocket]

Has anyone compared the monoprice solution to a good short USB and a long set of RCA analog cables? My preliminary plan for a USB connection was to move my DAC close to my Mac and get a 20 foot set of well shielded, low capacitance analog cables.