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Title: Cleanest computing platform
Post by: Ken Webster on April 22, 2019, 10:26:33 am
Hi, I tried asking this question before but didn't get a useful answer so I may as well ask again.

The situation is that we are using very old PCs to handle A/V at church.  The video projection PC is being upgraded, it handles lyric slides and videos. While we could combine music and lyrics into a presentation, this is not flexible to also cater for live worship where the lyric slides may well need amending.

I have for some time been looking into the requirements for our music PC.  This is about 75% of our worship, 25% being live.  CD's are ripped into .WAV files using EAC, we really try to avoid compressed, lossy, downloaded or streamed music if possible.  My question is, what computing platform, PC, All in one or laptop, is likely to cause the least adverse effects on what is essentially a small analogue PA system?  My concern is RF noise from the device and also supply earth stability.  Given that the device is plugged into the same supply and over copper connections whether analogue audio or digital, there may be some noise added to the system.  The aim is to eventually use an HDMI audio extractor/DAC.  While that gets the DAC outside the case, it's still connected to the PC via HDMI and supply earth.  The supply earth being the signal reference for the DAC.  Considering that the connectivity of supply earth to ground peg is likely poor in terms of signal reference potential (not fault condition), there seems a good chance that a device with unstable earth potential could have an adverse effect on single end audio.  I want to make a choice that gives me the best chance at the cleanest possible audio over the  analogue system.

Is there any information on this anywhere?

Regards,
Ken
Title: Re: Cleanest computing platform
Post by: Erik Jerde on April 22, 2019, 02:19:22 pm
Hi, I tried asking this question before but didn't get a useful answer so I may as well ask again.

The situation is that we are using very old PCs to handle A/V at church.  The video projection PC is being upgraded, it handles lyric slides and videos. While we could combine music and lyrics into a presentation, this is not flexible to also cater for live worship where the lyric slides may well need amending.

I have for some time been looking into the requirements for our music PC.  This is about 75% of our worship, 25% being live.  CD's are ripped into .WAV files using EAC, we really try to avoid compressed, lossy, downloaded or streamed music if possible.  My question is, what computing platform, PC, All in one or laptop, is likely to cause the least adverse effects on what is essentially a small analogue PA system?  My concern is RF noise from the device and also supply earth stability.  Given that the device is plugged into the same supply and over copper connections whether analogue audio or digital, there may be some noise added to the system.  The aim is to eventually use an HDMI audio extractor/DAC.  While that gets the DAC outside the case, it's still connected to the PC via HDMI and supply earth.  The supply earth being the signal reference for the DAC.  Considering that the connectivity of supply earth to ground peg is likely poor in terms of signal reference potential (not fault condition), there seems a good chance that a device with unstable earth potential could have an adverse effect on single end audio.  I want to make a choice that gives me the best chance at the cleanest possible audio over the  analogue system.

Is there any information on this anywhere?

Regards,
Ken

Toss a simple USB audio output device like the radial one on pretty much any functional computer and you’ll be fine.  If you’ve got ground loop problems then consult an electrician or move the computer to the same circuit as your mixer.

Honestly it sounds like you’ve been paying too much attention to the home stereo audiophools.  You’re probably getting more “damage” to your signal through your PA setup than you’ll ever get through a functional computer system.
Title: Re: Cleanest computing platform
Post by: Ken Webster on April 22, 2019, 11:07:45 pm
Toss a simple USB audio output device like the radial one on pretty much any functional computer and you’ll be fine.  If you’ve got ground loop problems then consult an electrician or move the computer to the same circuit as your mixer.

Honestly it sounds like you’ve been paying too much attention to the home stereo audiophools.  You’re probably getting more “damage” to your signal through your PA setup than you’ll ever get through a functional computer system.

Ta, yes, a USB based DAC would be an easy way to just do sound but I want the 2 computers set up identically so they can be used as fail-over for each other or even is a dual role if need be.  The only way to control the projector is via remote which is very marginal at the distance.  The remote has a video mute which can be used to blank the screen while the video or slide presentation is being cued or during communion focus or preaching. However, it may not un-mute when needed.  So there is a need to control the A/V feed and blank screen from the desk.  To solve this, we are aiming to do HDMI over cat 6 through an HDMI switcher.  This will allow us to simply switch between video sources (computers, disc player etc) or blank the screen.  We have already started installing the HDMI cabling and testing reveals a far superior image clarity on the projection screen even though the resolution hasn't changed.  This has been tested with an HDMI audio extractor and the audio quality is very good.  All this is good for the A/V side of things but what about audio only?  You can get HDMI switches that allow the audio and video to be sourced separately from different device.  Doing it this way solves a lot of issues with the professionalism of the presentations and uses the same DAC for everything maintaining consistent sound quality.  It may well be cheaper to go for a simpler switcher and a simple USB DAC to handle the music & A/V separately.

Yeh, I figured this would give the impression I listen to home HiFi advice too much.  Like many of us I do like to have nice music at home though I definitely wouldn't call myself an audiophile.  However I am well aware of the principal that the audio chain is made of many links that each degrade the sound quality.  Therefore the way to setup a superior system is to start with the best available source, then minimise both the number of links as well as the noise and distortion at each ink.  This is the reason I have made an effort to obtain the best quality music files that I can.  I chose EAC ripping because it's free and well regarded for accuracy, though it can be a pain to learn to use.  Yes, I know older audiophiles have used it.  It beats downloads or WMP ripping for accuracy  hands down.  There are other accurate rip options but this is free.  I have been all over this PA system from end to end and the clarity is now good.  There are other issues with the room though but at least the system is pretty much as good as I can get it now.  In fact my audiophile friend tells me it's the best, true sound reinforcement system he has heard.  So what a I am trying to do here is simply complete the last links in this setup/upgrade strategy.   I am well aware that historically PCs were considered very poor for S/N.  PC PSU filtering was historically pretty rubbish in terms of affect on S/N.  Same can be said of RF shielding.  I am aware these things and sound cards have improved quite a bit in recent years, I just don't know how much.  I am not too concerned about sound cards if we go to an external DAC.  I am not too concerns about earth loop hum as that is under control now but I am concerned about choosing the cleanest option with new equipment and avoiding band-aids after purchase.  The is a lot to consider, often laptops don't support audio well.  I have one that will not take an analogue mic input though by it's spec it should.  OP and hardware don't always wok well together.  I am a bit dubious about lite computing devices for this reason.  However a lite option may generate less noise, maybe not, I don't know.  So, I am just putting a feeler out there for advice on it.  Which is cleanest?

If the earth is not taking noise to ground well, an electrician will not be helpful with that, at least not the ones around here.  They only care that it's safe in regard to supply spec and have no idea about mV earth reference stability.  That isn't an audiofool thing BTW, it's just part of the well known standard performance optimisation strategy, combining many minor improvements at every link to achieve a much larger sum total improvement overall.  I have been doing this a long time and know from decades of experience this approach works.

Ken
Title: Re: Cleanest computing platform
Post by: Erik Jerde on April 22, 2019, 11:25:23 pm
Ta, yes, a USB based DAC would be an easy way to just do sound but I want the 2 computers set up identically so they can be used as fail-over for each other or even is a dual role if need be.  The only way to control the projector is via remote which is very marginal at the distance.  The remote has a video mute which can be used to blank the screen while the video or slide presentation is being cued or during communion focus or preaching. However, it may not un-mute when needed.  To solve this, we are aiming to do HDMI over cat 6 through an HDMI switcher.  This will allow us to simply switch between video sources (computers, disc player etc) or blank the screen.  We have already started installing the HDMI cabling and testing reveals a far superior clarity on the projection screen even though the resolution hasn't changed.  This has been tested with an HDMI audio extractor and the audio quality is very good.  All this is good for the A/V side of things.  You can get HDMI switches that allow the audio and video to be sourced separately from different device.  Doing it this way solves a lot of issues with the professionalism of the presentations and consistently uses the same DAC for everything maintaining consistent sound quality.  It may well be cheaper to go for a cheaper switcher and a simple USB DAC to handle the A & V separately.

Yeh, I figured this would give the impression I listen to home HiFi too much.  Like many of us I do like to have nice music at home though I definitely wouldn't call myself an audiophile.  However I am well aware of the principal that the audio chain is made of many links that each degrade the sound quality.  Therefore the way to setup a superior system is to minimise both the number of links as well as the noise and distortion at each ink.  This is the reason I have made an effort to obtain the best quality music files that I can.  I chose EAC because it's free and well regarded for accuracy, though it can be a pain to learn to use.  Yes, I know older audiophiles have used it.  It beats downloads or WMP ripping for accuracy  hands down.  There are other accurate options but this is free.  I have been all over this system from end to end and the clarity is good.  There are other issues with the room though but at least the system system is pretty much as good as I can get it now.  In fact my audiophile friend tells me it's the best, true sound reinforcement church system he has heard.  So what a I am trying to he here is simply complete the last links in this setup strategy.   I am well aware that historically PCs were considered very poor for S/N.  PC PSU filtering was historically pretty rubbish in terms of affect on S/N.  Same can be said of RF shielding.  I am aware these things and sound cards have improved quite a bit in recent years, I just don't know how much.  I am not too concerned about sound cards if we go to an external DAC.  I am not too concerns about earth loop hum as that is under control now but I am concerned about taking the cleanest option when choosing new equipment.  The is a lot to consider, often laptops don't support audio well.  I have one that will not take an analogue mic input though by it's spec it should.  OP and hardware don't always wok well together.  I am a bit dubious about lite computing devices for this reason.  So, I am just putting a feeler out there for advice.

If the earth is not taking noise to ground well, an electrician will not be helpful with that, at least not the ones around here.  They only care that it's safe in regard to supply spec and have no idea about earth reference stability.  That isn't an audiofool thing BTW, it's just part of combining many minor improvements at every link to achieve a much larger sum total improvement overall.  I have been doing this a long time and know from decades of experience this approach works.

Ken

You're going to be best served by keeping your audio path separate from your video path - at least at the level it sounds like you're working at.  Even when I'm routing audio through a video router (Ross Ultrix, ~$50K) I still land each audio source separately to the audio console.  That way level differences are easily handled if you're switching sources.  As far as cleanest source, you're still not going to get any better than a simple USB DAC.  One like the radial I mentioned earlier that is bus powered and doesn't require drivers on any (modern) system.  It's also significantly simpler than getting a video switch and audio extractors involved.  There's a lot less to go wrong and it's a lot easier to troubleshoot.

You are smart to get a video switch in place to feed your projector.  The ability to dump to a graphic or to black is really nice, especially if the worship leader or pastor wants to stop by pre-service and check their slides without them going up on the screens.  You can also check video audio levels in your cans pre-service without having to throw them up on the screens.  If you're intending to be able to cut sources live make sure you have a switch that is either two bus or is really fast.  They've gotten a lot better in even just the past five years but there can still be some really noticeable cut delay on some cheaper units.  You also want to make sure that you get one that will do scaling.  The ones that don't do scaling will often make the projector re-sync it's signal every time you change sources.

Title: Re: Cleanest computing platform
Post by: Ken Webster on April 24, 2019, 07:28:59 pm
You're going to be best served by keeping your audio path separate from your video path - at least at the level it sounds like you're working at.  Even when I'm routing audio through a video router (Ross Ultrix, ~$50K) I still land each audio source separately to the audio console.  That way level differences are easily handled if you're switching sources.  As far as cleanest source, you're still not going to get any better than a simple USB DAC.  One like the radial I mentioned earlier that is bus powered and doesn't require drivers on any (modern) system.  It's also significantly simpler than getting a video switch and audio extractors involved.  There's a lot less to go wrong and it's a lot easier to troubleshoot.

You are smart to get a video switch in place to feed your projector.  The ability to dump to a graphic or to black is really nice, especially if the worship leader or pastor wants to stop by pre-service and check their slides without them going up on the screens.  You can also check video audio levels in your cans pre-service without having to throw them up on the screens.  If you're intending to be able to cut sources live make sure you have a switch that is either two bus or is really fast.  They've gotten a lot better in even just the past five years but there can still be some really noticeable cut delay on some cheaper units.  You also want to make sure that you get one that will do scaling.  The ones that don't do scaling will often make the projector re-sync it's signal every time you change sources.

Ta for that, some good points.  I like some of the features with the radial USB direct box.  Seems a good option to at least separate A/V stream from pure digital audio.  I may still go with  a switcher and extractor for all A/V sources though as I'm currently a bit short on mixer inputs beyond the stage lines.  The fact is that we mostly only play video from the one source which looks like becoming a laptop. The extractor outputs to RCA which bypasses gain on the board so, in the event of switching video sources (unlikely), it's a simply matter of fade out, switch HDMI source then fade in.  As for the music Computer, I'm leaning toward a PC again simply because they are a more easily serviceable item that tends to outlast the compact options.  Still don't have an answer to my original question on electrical noise, especially earth noise.  I guess that using an external DAC with XLR (lift earth) is going to minimise that to whatever is eddies around the supply earth.  Still would be interested in decent PC PSU filters.
Title: Re: Cleanest computing platform
Post by: Matthias McCready on April 25, 2019, 12:56:15 am
The Radial USB Pro is a great product, on and off the stage. I have never under any circumstance heard "electrical" noise coming from it, I use these interfaces almost every day, in various venues and with lots of different computers.

I would keep video and music playback separate. For the space I love rack mounted mac mini's, many of my FOH locations have 2-3 mac mini's (just for audio). Although really any computer, even old curmudgeonly laptops, tend to be just fine for high-quality audio (without any electrical noise). Playing back music does not take a lot of processing power and is not heavy lifting by any means. If you have a decent DAC and a large hard enough hard drive; a windows 98 machine would even fit the bill and not have any weird sounds.  ;D Bring the back the beige!

As far as "audiophile" standards go any computer reading WAV/FLAC is a good source, (lower error rates compared to read rates, even of expensive players). If you have a decent external DAC your results will be good. As to what quality of DAC, should you get  I highly doubt a Radial would be the weak link in the chain. Even using it with D&B, JBL, L Acoustics, Meyer, or Nexo I never thought "I could really use a better DAC." More serious sound issues are usually related to speaker quality, deployment, room acoustics, and operator ability. Even MP3's over 3.5mm will sound good on a well-deployed quality rig, anything else is icing on the cake.

I am not sure what this "extractor" business you are talking about is, but it sounds like something to be avoided. If video world wants a switcher great, any quality switcher will offer XLR outputs. Good video equipment costs serious cash, it is a much more expensive game to be in compared to audio, as is such avoid cheap products when possible, in my experience you get what you pay for.

If you do not have enough I/O on your current console but are determined to keep it perhaps get a small 4-6 channel external mixer. This will allow for control over your different computer audio sources. At minimum (if I understand your situation correctly) you will want a stereo music input and a stereo video playback, 4 channels.

---




Title: Re: Cleanest computing platform
Post by: Erik Jerde on April 25, 2019, 08:35:50 am
any quality switcher will offer XLR outputs.

Actually anything approaching high end doesn’t do anything with audio.  I have only seen audio capabilities on gear that’s rather low end all-in-one type boxes.  Some implementations, even on $4K switcher/scalers have been decidedly poor, noisy, and lots of crosstalk.
Title: Re: Cleanest computing platform
Post by: Stephen Swaffer on April 25, 2019, 07:22:55 pm
Ta for that, some good points.  I like some of the features with the radial USB direct box.  Seems a good option to at least separate A/V stream from pure digital audio.  I may still go with  a switcher and extractor for all A/V sources though as I'm currently a bit short on mixer inputs beyond the stage lines.  The fact is that we mostly only play video from the one source which looks like becoming a laptop. The extractor outputs to RCA which bypasses gain on the board so, in the event of switching video sources (unlikely), it's a simply matter of fade out, switch HDMI source then fade in.  As for the music Computer, I'm leaning toward a PC again simply because they are a more easily serviceable item that tends to outlast the compact options.  Still don't have an answer to my original question on electrical noise, especially earth noise.  I guess that using an external DAC with XLR (lift earth) is going to minimise that to whatever is eddies around the supply earth.  Still would be interested in decent PC PSU filters.

I'll stick my neck out a bit here.  There is nothing magical about being connected to earth and dealing with earth eddy currents.  If you built your entire system on a large copper plate that was isolated from earth, but had good connections and ran it off batteries that would work just fine-no earth connection needed.

I am not a Mac advocate (We have a good natured Mac/PC rivalry-Pastor loves them, I tolerate them in general as I am required to use PCs at my day job-after all PC or Mac its a tool with pros and cons.)  However, I very much like the Mac/QU combination we use.  The QU is OS compliant and the MAC sees it as an audio device-so digital from the Mac in to the QU without a DAC until the output of the QU.  I'm not sure how much less "noisy" an interface you could possibly get?

I understand the advantages of a switcher-but running Propresenter on the Mac covers all of our video needs and the Mac-QU connection cleanly handles our audio.  Perhaps we will get "better" someday-but when you are doing live media presentations that often change on the fly there is a LOT to be said for a simple hardware setup.
Title: Re: Cleanest computing platform
Post by: Matthias McCready on April 25, 2019, 10:35:27 pm
Actually anything approaching high end doesn’t do anything with audio.  I have only seen audio capabilities on gear that’s rather low end all-in-one type boxes.  Some implementations, even on $4K switcher/scalers have been decidedly poor, noisy, and lots of crosstalk.

I stand corrected... I am not a video guy and have never touched anything nicer than a Roland switcher  ;D

Thanks for the correction Erik
Title: Re: Cleanest computing platform
Post by: Ken Webster on April 25, 2019, 11:32:20 pm

I am not sure what this "extractor" business you are talking about is, but it sounds like something to be avoided. If video world wants a switcher great, any quality switcher will offer XLR outputs. Good video equipment costs serious cash, it is a much more expensive game to be in compared to audio, as is such avoid cheap products when possible, in my experience you get what you pay for.

If you do not have enough I/O on your current console but are determined to keep it perhaps get a small 4-6 channel external mixer. This will allow for control over your different computer audio sources. At minimum (if I understand your situation correctly) you will want a stereo music input and a stereo video playback, 4 channels.

---

On the audio extractor:  HDMI is a mixed A/V bit-stream.  The extractor, extracts the audio bit-stream from that mixed stream and feeds the audio bit-stream to an integrated DAC which outputs analogue audio to a desk input.

I use something like this at home I have a vintage analogue HiFi and use an Essence HDACC to extract and convert digital audio to feed the HiFi.  To satisfy the family's desire/need for remote control, I put the HDACC in the analogue amps tape dubbing loop to provide remote volume control for the analogue sources.  This way, I don't have to put up with the TVs inadequate speakers because of the families need for a remote volume control.  In truth, I think my 80s AMC CD8a player provides slightly nicer analogue audio than the HDACC but they are pretty close to equal with a 1411 bit stream.  But that's another story.

Back to the church PA though:
I don't need to use stereo on the church mixer though I have been doing that because of split tracks.  However, the worship coordinator has decided to drop all spit tracks so I can go to mono channels now which will help with the shortage of inputs.  I have 12 stage inputs and 4 non stage.  I have been using inputs 11 & 12 (dual TRS/XLR) for the music PC or for stage Hi-Z because a service requires one or the other, not both.  For non stage sources we have:
Music PC (2ch)  currently 2 RCA in, Probably go to 1 XLR mono in.
Video PC (2ch) currently 2 RCA in, probably go to 1 RCA mono from HDMI switch.
Disc Player (2ch) currently 1 RCA in, probably go to 1 RCA mono from HDMI switch.
Radio Mic (2ch) currently 2 XLR in and will remain so.
portable device input (2ch) currently 1 RCA mono.

The extractor has RCA audio, I didn't get a say on this.
I like the fact the radial box is XLR and has ground lift. (isolates ground from signal path)

We may not strictly need all that but I think that given some things are RCA while others are XLR, if I go to merged mono, I will have enough inputs without taking up stage lines.

Ken
Title: Re: Cleanest computing platform
Post by: Jean-Pierre Coetzee on April 26, 2019, 07:55:31 am
You really need a disc player when you have a dedicated music PC? Another thing how often do you actually need to use a disc?

I don't think I've touched a CD in a few years other than for kids talent shows and even then popping it into my relatively old MacBook Pro has served my needs just fine, granted I do run a DAC so that I can get balanced audio out...

Regarding your video pc, I don't see a problem with running from a video switcher. I do this in two of our small venues, wouldn't do it in a venue that needs a dedicated technical person but its very easy to tell a presenter that this button switched between inputs and this knob is the volume and he doesn't need to worry about anything else.

In our larger venue, this will never be an option because the potential for problems is just too high. If you try to sell me anything with an RCA connector I will probably laugh at you.

One last question, why do you need a portable device input when you have a dedicated music pc? If that really came up as a need for one of the services you can surely just swap some cables out.
Title: Re: Cleanest computing platform
Post by: Ken Webster on April 26, 2019, 06:32:42 pm
You really need a disc player when you have a dedicated music PC? Another thing how often do you actually need to use a disc?

Well, you never know what someone might bring in for some presentation or other. No we haven't used it in a while but the last time it was needed, we couldn't actually cue up the video without the projection screen which was in use.

I'm just going through how we can setup what we have to actually work well. We may not keep a disc player but most people would have no idea how to rip a DVD or Blu-ray to a file, they will simply bring a disc that they have or a streaming link.  While we can stream, it isn't reliable, usually OK but.... not always.

If we can switch video projection stream from either computer and can play both DVD & Blu-ray, then video cuing this media is resolved, no need for a player.  However $200 gets you a mini player that does about every disc media and USB based file type and well as streaming so that's not a bad deal for a fallback option.  So I'm just putting it out there as a possible option.

Ken
Title: Re: Cleanest computing platform
Post by: Ken Webster on April 26, 2019, 07:08:40 pm

In our larger venue, this will never be an option because the potential for problems is just too high. If you try to sell me anything with an RCA connector I will probably laugh at you.

One last question, why do you need a portable device input when you have a dedicated music pc? If that really came up as a need for one of the services you can surely just swap some cables out.

The things on RCA were budget options at the time, except the extractor which I didn't get a say about.  It's only a very short lead so induced noise is not an issue, still I wouldn't have recommended it.

The portable device input is there because the sound system isn't just reserved for worship services only.  Having a 3.5 mm jack available just makes it simple and easy to play something with the least training or messing about.
Title: Re: Cleanest computing platform
Post by: Scott Holtzman on April 27, 2019, 01:41:49 am
Well, you never know what someone might bring in for some presentation or other. No we haven't used it in a while but the last time it was needed, we couldn't actually cue up the video without the projection screen which was in use.

I'm just going through how we can setup what we have to actually work well. We may not keep a disc player but most people would have no idea how to rip a DVD or Blu-ray to a file, they will simply bring a disc that they have or a streaming link.  While we can stream, it isn't reliable, usually OK but.... not always.

If we can switch video projection stream from either computer and can play both DVD & Blu-ray, then video cuing this media is resolved, no need for a player.  However $200 gets you a mini player that does about every disc media and USB based file type and well as streaming so that's not a bad deal for a fallback option.  So I'm just putting it out there as a possible option.

Ken
Frankly you are never going to get the results you want without a switcher with a cue monitor.  There are several low end ones that now have scalers.  It is easy to use and will step up the quality of your presentations.

Sent from my VS996 using Tapatalk

Title: Re: Cleanest computing platform
Post by: Jordan Wolf on April 28, 2019, 12:31:37 am
The Roland V1 series units (available in HDMI and SDI variants) are pretty nice for a low-end switcher/scaler. You can embed & de-embed audio to/from HDMI/SDI, which can be quite nifty.

I like the V60 as a step up in the control surface area, with the added functionality of an Aux output. It is primarily and SDI switcher, though, which may not suit your workflow.

Kramer has some units that have set & forget features with a punch & crunch style button interface that works well with volunteers.

Choose a switcher that affords some flexibility later on, should you upgrade or expand your ministry technology.
Title: Re: Cleanest computing platform
Post by: Ken Webster on April 28, 2019, 06:11:01 pm
The Roland V1 series units (available in HDMI and SDI variants) are pretty nice for a low-end switcher/scaler. You can embed & de-embed audio to/from HDMI/SDI, which can be quite nifty.

I like the V60 as a step up in the control surface area, with the added functionality of an Aux output. It is primarily and SDI switcher, though, which may not suit your workflow.

Kramer has some units that have set & forget features with a punch & crunch style button interface that works well with volunteers.

Choose a switcher that affords some flexibility later on, should you upgrade or expand your ministry technology.

Ta, I had noticed the Rolands online.  I think I only need a very simple one, perhaps the V1 if it does scaling (didn't find any mention of that).  There is a local AV business so I'll go talk to them and see what they can provide.  I've been looking into this for a while to get at least a bit informed before approaching a business.

Ken
Title: Re: Cleanest computing platform
Post by: Ken Webster on May 26, 2019, 10:27:14 pm
Hi again,

I have started having some conversations on this at church and have setup some of my own equipment to experiment at home.  Right now I am playing EAC ripped WAV worship files on my HP Pavilion laptop through USB 3 into an Essence HDACC (USB 2) outputting to my Sennneiser HD650 cans.

I have to say it sounds darn good though subtly better than the laptop audio jack.  I
guess the issues come home to roost when a whole PA system is connected badly.

However when I looked up the Radial USB PRO specs,  it says it only supports USB 1.1 (Shock)
Come on, we are up to USB 4 now or soon will be.

I know that USB 1.0 supports only 1.5 Mbps and full speed supports 12 Mbps.
USB Pro is 1.1 Full Speed so that is more than enough for ripped CDs but I am a bit concerned about comparability with new computers and future proofing.  Also read that older windows versions down sample USB 1 bit streams.  I hope that is no-longer the case.  Is there something a bit more up to date? 

Ken
Title: Re: Cleanest computing platform
Post by: Mac Kerr on May 26, 2019, 10:43:13 pm
However when I looked up the Radial USB PRO specs,  it says it only supports USB 1.1 (Shock)
Come on, we are up to USB 4 now or soon will be.

I know that USB 1.0 supports only 1.5 Mbps and full speed supports 12 Mbps.
It's 1.1 Full Speed so that is more than enough for ripped CDs but I am a bit concerned about comparability with new computers and future proofing.  Is there something a bit more up to date?

It's a 2 track device. A 24bit/96k stream is 575KB/s. I think that leaves like 2/3 of that USB bandwidth as headroom. So far all new USB specs have been backward compatible with all previous versions. What is the problem you envision?

Mac
Title: Re: Cleanest computing platform
Post by: Ken Webster on May 26, 2019, 11:38:43 pm
It's a 2 track device. A 24bit/96k stream is 575KB/s. I think that leaves like 2/3 of that USB bandwidth as headroom. So far all new USB specs have been backward compatible with all previous versions. What is the problem you envision?

Mac

"So Far" sums it up.

Also, the bit stream from the PC will be at least stereo because that is the file source and the minimum setting windows 10 appears to support.  I intend setting the USB Pro to mono out.  The bit stream is from uncompressed CDs rips 44100*16*2 = 1.4112 Mbps, still well within 1.1 Full Speed (I think).

It just doesn't seem a good deal to buy really really outdated tech but I believe it will be adequate at least in the every near future, 3 years out, it may not be compatible with anything.

As stated above , Windows has been known to down sample over USB 1 and I don't know the current W10 situation.  I can see from my HDACC that the incoming USB 2 stream is 44.1k.  I don't know how W10 will react to USB 1.1, I have no examples to test cos it's ancient history.

You know that the Devil is in the detail right?

Ken
Title: Re: Cleanest computing platform
Post by: Jeff Lelko on May 27, 2019, 12:04:05 am
Hi Ken.  If USB really scares you that much, why not consider an ethernet solution such as Dante?  I'm reading through this thread though and am not really understanding what it is that you're trying to accomplish.  When in doubt keep it simple!  Hope this helps!
 
Title: Re: Cleanest computing platform
Post by: Ken Webster on May 27, 2019, 04:15:37 am
Hi Ken.  If USB really scares you that much, why not consider an ethernet solution such as Dante?  I'm reading through this thread though and am not really understanding what it is that you're trying to accomplish.  When in doubt keep it simple!  Hope this helps!

USB doesn't scare me, I am just trying to sort out what will work best and continue to do so for a reasonable time into the future.  Best includes sound management issues plus sound quality, little things like S/N, clarity, cuing and controlling video feeds to the projector.  I know that computers have come a long way but they come from a history that is riddled with very poor S/N mainly due to internal RF, unstable noisy earth, processing jitter, interrupted processing due to other processes running etc.  I have seen and heard demos where for example simply playing a compressed file causes enough processing load to make audible jitter.  My laptop I am trialing this on right now has several times interrupted the playing bit stream simply because I opened a window.  That doesn't happen when I simply use the internal DAC and headphone port.  The wisdom is to use an external DAC to improve S/N which it does but also allows other actions to interrupt the audio bit stream.  So I am just trying to find out how to get around these things so it works smoothly and professionally.  I don't recall having these interruptions with and HDMI stream passing through an Audio extractor.  I should test that again I guess.

We have been trialing a video laptop at church with that arrangement.  However, the extractor supplied by the AV business has a somewhat dud DC socket (poor spring tension).  When the power breaks, the video stream passes through passively but the audio extraction fails.  The laptop then takes 5 min or so (dead air) to detect this fault and switch audio back to internal analogue.  I was then able to Jerry rig a 3.5mm jack to RCA to get sound back again.  Not ideal but it got sound.  However extractor DC was restored and after another 5 min or so (dead air) the laptop switched audio back to the HDMI stream.  Personally I'd like to remove the DC socket and simply solder the DC lead directly to the board because this is just the most reliable way to go with it despite it being a warrantied item (low cost though).   In the end, we will likely replace this item with a HDMI switcher that includes this function anyway.

So basically I just want all this to work reliably and to a high standard which has never been the case previously as the original implementation was a bit amateurish in terms of cuing and signal clarity.  This was initiated because of the age of the current computers which currently have no faults.    So I want to take the opportunity to upgrade the implementation to fit our use well.

I just don't like replacing old USB 2 gear with USB 1.  That seems like the wrong direction to me, even if it is adequate.

Ken
Title: Re: Cleanest computing platform
Post by: Paul Miller on June 05, 2019, 06:12:28 am
Ken please don't take this the wrong way, but...

This thread has been going on for 6 weeks and it seems like you're no closer to a solution that makes you happy. I have a phrase for when I find myself in one of these situations: Paralysis by Analysis. It happens when we're too caught up in scrutinizing the minutiae of every possible solution, and it keeps us from moving forward with a project.

So here's a suggestion: Buy a  Peavey PV USB (https://www.bhphotovideo.com/c/product/759075-REG/Peavey_USB_P_USB_P_USB_Direct.html) and use that for now. It doesn't have a world class DAC, it may be USB 1.0, I don't know and I don't care. It's less than $60, it's class compliant, has ground lifted XLR outs plus a mono/stereo switch, it just works. And I sincerely doubt this will be the weak link in your audio chain. Plug in, make noise, be happy. Life's too short.
Title: Re: Cleanest computing platform
Post by: Stephen Swaffer on June 06, 2019, 09:40:45 pm
It is my understanding that USB ports are identified by the highest standard they support.  Devices that plug into the port are rated by the earliest/lowest standard they require.  If the data stream a device creates only requires 1.1 speeds, labeling it as 2.0 unnecessarily indicates it can't be used with a 1.1 port.

It is unlikely that any of the $60 class USB interfaces-whether USB 1.1 or 2.0 will be outdated/obsolete before your current smartphone.

Title: Re: Cleanest computing platform
Post by: Ken Webster on June 12, 2019, 08:21:03 am
Ken please don't take this the wrong way, but...

This thread has been going on for 6 weeks and it seems like you're no closer to a solution that makes you happy. I have a phrase for when I find myself in one of these situations: Paralysis by Analysis. It happens when we're too caught up in scrutinizing the minutiae of every possible solution, and it keeps us from moving forward with a project.

So here's a suggestion: Buy a  Peavey PV USB (https://www.bhphotovideo.com/c/product/759075-REG/Peavey_USB_P_USB_P_USB_Direct.html) and use that for now. It doesn't have a world class DAC, it may be USB 1.0, I don't know and I don't care. It's less than $60, it's class compliant, has ground lifted XLR outs plus a mono/stereo switch, it just works. And I sincerely doubt this will be the weak link in your audio chain. Plug in, make noise, be happy. Life's too short.

No problem, not taking it the wrong way.  The holdup is not technical, I am moving forward on this.  I need to present options to the church for funding approval and well, I haven't managed to get a slot yet as there are other things under discussion.  I have also been a bit tied up with some HDMI over cat 6 installation and a component warranty replacement / testing etc.  Oh and HDMI bleeds RF so I'll have to get onto that too (kind of expected that possibility though).

I did get feedback from Radial when I queried the use of USB 1.1.  Series 1 allows the device to plug and play without a driver.  So I'm pretty reconciled to that now.  Thanks for the heads up on the cheaper Peavey option, I'll check it out.

Ken
Title: Re: Cleanest computing platform
Post by: Ken Webster on June 12, 2019, 08:39:50 am
It is my understanding that USB ports are identified by the highest standard they support.  Devices that plug into the port are rated by the earliest/lowest standard they require.  If the data stream a device creates only requires 1.1 speeds, labeling it as 2.0 unnecessarily indicates it can't be used with a 1.1 port.

It is unlikely that any of the $60 class USB interfaces-whether USB 1.1 or 2.0 will be outdated/obsolete before your current smartphone.

You probably correct, at least I will avoid the aural implant as long as possible. ;)
Title: Re: Cleanest computing platform
Post by: Ken Webster on August 21, 2019, 05:06:31 am
Well, the good news is that among dealing with some restructuring, constitutional and procedural changes, I have funding approval for replacement PC and associated items.

I did not get approval for a an AV switcher, they opted to support a single video source instead.  People now have to provide video files or links in time to add them to the video presentation.
No more last minute DVDs.  Solves the problem.

Major equipment has been ordered, hope the installation goes well.

What I have learned from this is that computing gear is still very noisy.  The HiFi sector are significantly moving away from computer audio because it is incapable of matching CD S/N without very very significant investment on cleaning up the noise, ground isolation, power and USB filtering for RF and EM ahead of the DAC.

However,  PC provides the convenience of an easily managed playlist the signal is going through a desk and EQ which tend to be significantly weak links anyway (we all knew that though).  The Radial USB-Pro block diagram indicates a filter on the USB input.  The company seem a bit coy about what that actually does but I guess something is better that nothing.  It does provide XLR ground lift and phantom power protection which I count as significant features (isolate PA from PC ground and our desk has global phantom).  So I tend to think this is close to or perhaps a little above what is necessary for the current system.  The desk and EQ are old and use carbon fadders.  Should be replaces sometime soon, hopefully with low noise gear.

Thanks everyone for you input, much appreciated.

Ken