USB cables vs. RCA cables for audio

This viewer's source is far away from his DAC. Should he use a long USB and short RCA interconnects or the opposite, and why? Have a question you want to ask Paul? www.psaudio.com...
I have finished my memoir! You can go read it now: www.amazon.com... It's called 99% True and it is chock full of adventures, debauchery, struggles, heartwarming stories, triumphs and failures, great belly laughs, and a peek inside the high-end audio industry you've never known before.
I plan a few surprises for early adopters, so go to www.paulmcgowa... and add your name to the list of interested readers. There's an entire gallery of never before seen photos too.

[@editorjuno]

Paul should have specified a *powered* USB hub. A passive hub is essentially just a splitter/coupler and doesn't do anything about maintaining the required signal voltage level over the increased distance.

[@amb3cog]

Yup, very good point. 👍

[@JustinoKusinero]

Might i suggest: STEP 1: Place your Mac and DAC at the same place (short usb and short RCA) STEP 2: Get a 20 ft. HDMI cable to connect your mac to your display monitor. STEP 3: Wireless keyboard and mouse. Audio problem solved.

[@IHearEverythingDude]

Yup the best idea. There are tests on audioscience forum that show that long USB cables are really bad idea. USB cable should be as short as possible

[@amb3cog]

Good idea. I have a 25ft HDMI cable that works great, and it's just a low budget Amazon one. Nothing fancy at all.

[@IHearEverythingDude]

@@mamaluigi0631 www.audiosciencereview.com/forum/index.php?threads/do-usb-audio-cables-make-a-difference.1887/

[@ford1546]

Here we talk about audio transmission over usb? length has nothing to say when it comes to noise. usb transmits 5V to GND. It is here mainly you transmit audible noise. Remember inside a PC there is a lot of noise.

[@PanAmStyle]

skrotkalle skrotkalle Which is why there is a market for hot-rodded Mac Minis that have “better” power supplies, etc. I’m not endorsing that, just observing.

[@aydngulgun8936]

Hey Paul, there are some usb cables called active or powered that can maintain signal integrity in longer cables. They usually have repeaters in every 3 to 5 meters to repeat the signals, i have even seen ones as long as 30 meters (100feet I think) and like everything else good ones are really good. Great channel, great videos as always. Much love from Turkey.

[@kevinh9030]

this is the answer

[@Oystein87]

No issue with USB 2.0 up to 10meters. I have used 15meters without issues. But that's almost a gamble at that point.

[@aydngulgun8936]

@@Oystein87 did you test the connection for speed, latency, and bandwidth for those around-10-meter cables? they are barely okay for basic connections but here he is talking about dsd and stuff.

[@Oystein87]

@@aydngulgun8936 Like I said..: Had no issues at all..

[@PanAmStyle]

Øystein I’ve had trouble with 14 feet, though I cannot say for certain that the dropout issues I’ve noticed were solely due to USB (3.0) cable length. My iMac came with 8GB RAM, so it may have been an issue with memory and too many apps on the Mac being open while playing music. Not long ago I upgraded the Mac to 40GB. That may have improved things; I’d have to run some (uncontrolled) tests to get a sense of that.

[@dcho4791]

Since he has Jriver 25 on his wifi networked Mac, I suggest he by Jrivers IdPi Music Server and connected via wifi to his dac with a short USB cable. The IdPi is a Raspberry Pi 3B+ and the Jriver 25 software running as a headerless server/renderer. The two copies of Jriver will detect each other and allow direct transfer of files from the Mac to the IdPi over his wifi network. This will allow placing the IdPi next to the dac and the dac close to the amp. Additionally a number of Raspberry Pi audio HATS could be used to provide SPDIF and/or an stereo analog output.

[@editorjuno]

Another point: for connecting a USB-driven DAC, it's best to use a decent quality USB cable with a cylindrical "ferrite bead" choke near the DAC end if the cable. This is the type of cable usually that's packaged with such DACs and is better for that application than the plain USB cables that are more than adequate for printers and other less noise-vulnerable devices.

[@janinapalmer8368]

Another way to do this would be to connect the USB cable ( very short ) into a converter unit fitted with spdif outputs and connect via optical fibre and at the other end use another converter in reverse ( these converters are universal in that they connect all audio transfer methods ... RCA , fibre optic, XLR balanced and USB 2.0 ... you can configure them to suit your purpose )

[@wurly1100]

Thanks for answering my question Paul! And Thanks to all the helpful comments posted. I'm going to give the powered USB a try but I'm also considering buying a Mac mini and placing that close to the gear. I can use Jremote and an ipad. The Outlaw RR2160 has a built in DAC that supports up to 24/192 but not DSD. I'm using a iFi Micro iDSD as the DAC between the iMac and Outlaw. Just trying to get the best sound with what I have, Always a work in progress. :)

[@yaniv-nos-tubes]

try an ipurifier3 every 3 or 5 meters with audio grade usb cable

[@ped-away-g1396]

neither. any long line-level cable is susceptible to noise even when shielded (ground can pick up noise too as there's no such thing as an absolute ground, the ground is just a reference). but if i had to choose one way, i'd go with long RCA. as distance is a really really big factor in the digital domain, long digital interconnects can lead to malfunctions like stutter, skipping, etc. but with long analog interconnects, you can boost the signal a little bit to maintain high SNR and lower the amplifier's gain to compensate for the stronger signal. or just use balanced transmission. the impedance of the cable is also not a problem. the amplifier's input impedance (if properly designed) will be too high for the cable's impedance to actually matter (6 to 7-digit range, usually). unlike speaker cables, speakers usually have very low impedance (2-digit range at most) so the impedance of the cables is more significant (the impedance of something alone barely means anything, it is the ratio and where in the circuit the most significant impedance is that really matters) though, don't use this statement as an excuse to purchase expensive speaker cables just yet. just ordinary power cords are perfectly fine for most cases.

[@wiredG]

The thing about that is... Digital noise is not a thing. Digital either works or it doesn't, only in edge cases would you be able to introduce noise and even then, the "noise" that you hear is not so much noise as signal cutting out and in repeatedly. If you need a long cable, I would consider going USB to ethernet cables since you can make those run for more than a 100m. If you for some reason need more than 100m you could go the USB to ethernet fiber route, but that starts getting expensive.

[@404BOOMER]

What is that white board with the black lines on it to the left of the sofa. It's sitting on a red table leaning against the wall? I've seen it in some of the other videos and wonder what it's for.

[@amb3cog]

It's an acoustic diffuser/absorber combo type thing. He talked about it when he got them a while ago for the new music rooms. They're supposed to work really well, but they're not cheap.

[@drwisdom1]

I have two Sony TA-E77ESD preamps. One is in the living room and the other is upstairs in the loft overlooking the living room. Both have amps and speakers. I wanted to connect the two preamps so when I am working I get sound out of all four speakers. Going from upstairs down through the wall to the basement, across the basement ceiling, and back up to the living room preamp is easily 75 feet. So I ordered a pair of adapters off Amazon that changes RCA to cat5 and strung cat5 cable (which I already had) between the locations. It seems to work like expected. How bad a solution is it? Am I losing sound quality?

[@ford1546]

Digital rca into a DAC is the best! Use a cable like a good antenna TV cable with multi-threaded center leads. 2 things that were not mentioned 1. USB can also transmit low frequency noise that you can hear. This comes from all the noise that is inside a PC. I've experienced it. 2. RCA cable can make ground loop. you have a PC that ground is connected to 230v GND and DAC not. If you connect the two together you get the ground loop. Not always you hear something about this problem in the speaker but you can.

[@awizardalso]

I have a small cable with 1/8th inch stereo plug in the sound card on my desktop computer, connected to the aux 2 input of my Panasonic integrated receiver RA-6100 with two RCA plugs. Even with two cheap speakers, the sound is good when I play music off KZbin. Even the music on your video at the end sounds quite good, too!

[@editorjuno]

U-Toob audio is notoriously second-rate -- about the same MP3 @128 -- so I'm not surprised your setup sounds "quite good" to you considering that sort of source.

[@awizardalso]

@@editorjuno It may have to do with the amp in the receiver. It covers the whole audio range without distortion unless I turn the volume too high for the speakers. I have 2012 songs, mostly MP3's, on an external hard drive. Most I recorded on the last computer, that I could record whatever was playing using Goldwave from KZbin. At least they couldn't tell I was recording them, like when downloading from sites like Napster and others as they knew you were downloading songs. I can't record anything from this computer except via a microphone in the sound card. That would diminish the sound quality.

[@gryffon7497]

If you run a USB to RCA from a PC to an amp, would that work?

[@JaiPandit1989]

I am struggling to find an answer for using USB or Digital coaxial, to connect my streamer(Bluesound node 2i and bypass dac) and my Pre amp. I am using Qobuz and Tidal for streaming hi res audio

[@juliaset751]

The PS Audio LanRover would be an ideal solution to this problem. I don’t think it’s for sale anymore; it used to be $600 when sold, so it’s not cheap. If it is no longer sold, that is a shame; it is such an elegant solution.

[@303nitzubishi4]

Interesting predicament. I think most would opt for a decent media server to set up at the amp and some software at the PC to interface with it through your LAN. Just my two cents

[@justins.1283]

Is that situation I find a USB to optical adapter orygen and then use an optical cable with no loss hardly

[@soring5880]

Looking at all these comment I gather 2 things: people do not listen to the question and every one is an expert. He asked about dsd files. These can only be sent trough usb. Not through optical, airplay, Bluetooth or any other option

[@wilcalint]

Confirmng what others have said here. You want to make sure that the USB hub is powered. I bought this USB Hub from Amazon: www.amazon.com/gp/product/B00DQFGH80/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 Crossing fingers that the external power supply really was that and it was.

[@kirkcunningham6146]

Yes, Outlaw is still around. Surround sound now. I have the 976 pre-pro and they are currently developing a new Dolby Atmos processor. Their amps are very good and based off of an ATI platform. They stay very low key in the marketplace.

[@jean-lucd3846]

USB 2.0 max cable length is 16 feet and 5 inches (5 meters). Though converting the USB signal to optical (Toslink) and feeding that to the DAC might be the best solution (Does your Mac not have SPDIF Toslink out ?). It also provides a galvanic isolation.

[@soring5880]

Jean-Luc D pretty sure you cannot send dsd via optical

[@jean-lucd3846]

Indeed. You have got a point there.

[@robinbrandl9388]

3:39 Paul trolling hard xD Great video

[@CHBen_]

What about the wires form the amp to the speakers? Can't you just run really long runs of those? And have the amp, DAC and Mac right next to each other

[@oysteinsoreide4323]

speaker cables are best when they are short.

[@dublb232]

Does the Mac have Bluetooth? If so, what would be wrong with purchasing an inexpensive BT receiver ($20 or less) for the DAC, and connecting the two that way? I have PA system that has two channels set up to receive a stereo Bluetooth signal and it works great! Would there be any degradation with BT, Paul?

[@james-xf1ox]

He wants to listen to DSD

[@dublb232]

@@james-xf1ox How does that change anything, if he's accessing it through his PC? I thought the issue was getting it from his mac, to the dac, and then to the power amp.

[@james-xf1ox]

@@dublb232 DSD can only be sent via usb from the computer

[@yaniv-nos-tubes]

ifi ipurifier 3 (130$)can solve that problem you'll have to use one every 3 m and use a quality usb cable (the cheapest audioquest usb will do). if you have a port for usb 3.0 (ss) on your pc you should use it and get usb 3.0 cables even if your dac is usb 2.0 the purifier is like a buffer for data which also reduce noise and it's meant for hi end audio unlike using a generic noisy usb hub

[@pdcragin33]

My thought is that Pro Audio folks lay long runs all the time, and have a variety of tools to fend off ill effects. Talk to Sweetwater or any other Pro dealer for their advice. They MAY suggest a $75 two channel Hum Eliminator with XLR, 1/4", and RCA Inputs and Outputs, or perhaps an even less expensive solution.

[@Kulvinder1974]

Would wireless not be any good? I had a similar problem not so long ago and I bought a wireless transmitter receiver system from Lindy Electronics LTD. I hope this message gets through okay.

[@scottyo64]

Dont they sell Outlaw at the Best Buy Magnolia stores? Thought I saw their prducts there.

[@pablov1973]

Please, place your MAC much closer to you audio system and forget about long cables.

[@PanAmStyle]

Just play vinyl ... 😝

[@wildcat1065]

You need to run the digital signals over a cat5 ethernet cable from your computer. (My computer is in another room to my hifi). You then need a network bridge to convert back to a usb into your dac through a short cable. If you go mac direct to dac the sound will sound flat. A Sonore microrendu is a superb $650 bridge that also removes noise and gives you cd quality plus from computer audio. I almost gave up on computer audio until I was put onto the Sonore.

[@oysteinsoreide4323]

I guess that moving the mac closer to the dac is a better option than that.... At least when it comes to cost.

[@wildcat1065]

@@oysteinsoreide4323 . Costwise yes, sonically no.

[@oysteinsoreide4323]

@@wildcat1065 moving the mac closer is free.... not exactly the other option..... the audio quality is about the same. What do you choose.

[@wildcat1065]

@@oysteinsoreide4323 . You seem more interested in getting the cheapest option than good sound. Have you tried what I am suggesting ? I can assure you that sonically there is no comparison - not about the same. Plug a mac straight into a dac and you will get mediocre sound. This is exactly what I used to do myself until I did what I explained. I am trying to help you here, but, if you are happy with plugging in via a short usb that's fine by me.

[@oysteinsoreide4323]

@@wildcat1065 Isn't you going to get a very good sound if you have a good DAC that you plug your mac into? Are there noise coming from the MAC that is not supposed to be in the sound? You must explain to me. And also please tell what type of USB cable and DAC you used before you went over to the sonore Rendu module.

[@FreudianSlipDK]

Corning optical USB 3 cables. Device transparent, 5Gb/s and 150' max range.

[@AngryChineseWoman]

If your setup allows it, any cheap usb a > b adapter beats any usb cable

[@rcdude86]

I just use airplay. But its limited to 16bit. Still nice sounded though.

[@SirRocksta]

Hey Paul, I hope you are reading this. I'm working at a hifi store in switzland. I really thank you for all of your videos. But I kinda disagree with you in this particular video. I would never run a USB cable longer than 5 meters, even if theres a hub in between, which could cause some loss in packages it sends out. I would prefer just running higher quality RCA cables from Audioquest, which are insanely good, to connect to the DAC. What I would prefer over that is getting a speerate Streamer which surely has a better output stage on the USB side than a Mac/Windows. Control everything from the Mac and then run short RCA cables to the DAC. What are your thoughts on this? Greetings Simon

[@bassman4632]

How long is too long for RCA cables?

[@LordVictorHalgaard]

I don't believe there is a specific limit, as such, simply the longer it gets, the more noise it picks up. So above a couple of meters you want to seriously consider balanced instead.

[@pchlars5666]

usb to optical ? and 20 ft optical ? usb to bt transmiter than to bt reciver and to the DAC ?

[@soring5880]

pchlars pretty sure you cannot send dsd via optical

[@pchlars5666]

@@soring5880 Oh. I did not caught it was about DSD. :)

[@TuiCatNZ]

Ummm you can certainly get long active (powdered) repeating usb cables. There not expensive.

[@Oystein87]

I have used up to 15meter long USB 2.0 connection without any issue. But 10meters is the recomended max.

[@mrlithium69]

that seems a bit much. I can confirm over 16 _FEET_ is going against the spec for USB 2.0, especially DACs

[@Oystein87]

@@mrlithium69 But it's not.. 10 METERS is no problem (The rest of the world use meters and not american feet..) 15 meters is ok for things that don't need much power. And a DAC has it's own power supply so only need to send the signal and no power.

[@randomgeocacher]

Øystein YMMV as soon as you go over length specs, your experiences may not match others. I have not experimented much with overlong USB, but I have with HDMI: 10m is extremely YMMV, one TV had extreme problems with many PC/Mac HDMI dongles over 3 different HDMI cables. Ended up going with an optical HDMI cable after realizing that even an active HDMI cable did not solve the problem. I’ve asked other people with similar setups, they have not encountered these problems - presumably something about this particular TV makes it unusually bad at receiving over long cables.

[@GertSterner]

Sound over USB uses other protocols than data over USB. Sound don't stop bad packages. So sound over USB need's a very good USB-cable. So both cables should be short and of good Hi-Fi Quality.

[@Cpt.Zer0]

Digital is data. 1 and 0's . There is no difference.

[@GertSterner]

​@@Cpt.Zer0 Try listning to a couple of usb-cables and get the "aha, there is a diffence!" experience.

[@GertSterner]

@@mrmaunz42 Try listning to a couple of usb-cables and get the "aha, there is a diffence!" experience. Then look it up in Google's database. Then you can be as stupid og special as you whish ;-)

[@GertSterner]

@@mrmaunz42 Well, look at the bright side. You just saved yourself a bunch of money on Hi-Fi equipment :-) . The Google database, is the one you search in, when you use the search field at google.com

[@GertSterner]

@@mrmaunz42 I actually have; both in electronic and computers. But that's not the point. If you, and perhaps Paul, can't hear it, then it is not for you. Enjoy your music :-)

[@Rob1972Gem]

All these great answers about cable length and noise in long cables USB drop offs ... JUST MOVE THE BLOODY MAC CLOSER TO THE HI-FI why complicate what is a very simple answer

[@johnsweda2999]

Alternatively you could go with a Bluetooth adaptor to USB about £25 aptX codec just as good or maybe better. There should be no issue running 25 feet Of RCA good quality cable especially if it's shielded preferably silver-plated OFC copper I would suggest. Or go with toslink if you got it.

[@james-xf1ox]

DSD won't work like that

[@Geerladenlad]

If optical is an option use that over USB.

[@ThinkingBetter]

Geerladenlad Optical is inherently poor on jitter as it is one-way data with the clock master in the source and not at the DAC. Audio data should be pulled on demand and not one-way pushed.

[@Geerladenlad]

@@ThinkingBetter the limitations in the optical have to do with the ends not the cable itself. That's why some people have those connections for the I forget what they're called they have the glass ends. AES/EBU?

[@Geerladenlad]

@@ThinkingBetter also if you use optical you don't have to deal with drivers to make things work.

[@Geerladenlad]

@@ThinkingBetter HDMI might be preferable.

[@ThinkingBetter]

Geerladenlad No, the problem is that optical audio is one-way. The rate of the PCM data is pushed by a crystal oscillator on the source side and jitter can occur in the path until data hits the DAC. The pull method with a precise oscillator in the DAC clocking the data into the DAC chip is much better. Jitter is only a real concern when data is pushed. Anyway, optical has the advantage of being isolating electrical noise and can go very far. Optical vs RCA, sure, pick optical.

[@Brown_Sound]

This sounds like a good use of your former product the LANRover for distant connections ( kzbin.info/www/bejne/pILNe56batqAaMk ). With that being said, you need the computer/render closer to the audio rig, just sayin'.

[@SuspiciousAra]

OMG! OK, i also want to answer this one. Why on earth would you RECODE the digital signal that was JUST decoded? ALWAYS use the analog output of the DAC to actually benefit of that DAC. If your DAC sucks, buy another DAC but do NOT decode the digital into analog to recode to another digital and then again in analog. That is just stupid.

[@entity279]

I don't think you understood the question. No re-coding is involved here. Mac outputs digital, which is converted to analog once in the DAC