Hello All

I have recently purchased a DAC by Cambridge Audio

http://www.cambridgeaudio.com/assets/documents/DAC_Magic_rear.jpg

I was quite unhappy with the sound of some of my digital music libray, even some of it being at high bit rates or 320 or lossless.

My digital library is on a mac mini. I also have beoport, beocentre 2 socket box and beolab 9 speakers.

The set up is as follows:

USB from MacMini to BeoPort

USB from MacMini to DAC

1/4 inch headphone jack from DAC to BeoPort

Essentially the DAC is used as an external sound card whilst retaining the functionality of the BeoPort.

 

The improvement in the quality of the sound is quite marked.. I'm hearing sounds on digital tracks (mostly mp3's) that i haven't heard before. 

I have a few questions for those who may be in the know:

1. Have I set the connects up correctly? Is there a better way to connect everything?

2. I have noticed a vast improvement in sound quality, however on many tracks i know hear an occassional crackle which is quite annoying. Im using a fairly cheap cable to connect......... Im wondering whether:

a. The issue is with cabling

b. Something to do with when ive ripped cd's to my MAC (ie dust on the track..havent worked out if the crackles appear in the same place constantly yet)

3. Netradio now cannot really be used with the DAC connected as the crackles and pops is dreadful- i assume this is poor phone line problem? Have tried a headphone jack splitter in the beoport so that dac can be easily turned on and off using the computer. However using the splitter jack (probably a cheap one) degrades the sound quality considerably. Would buying a good splitter solve the problem?

Any advice really appreciated (picture of rear of DAC below).

I hope I've made some sense

Best Wishes

 

David Coyne

Sydney, Australia

Hi David,

 

I'm thinking of getting a DAC and wondered if you managed to resolve your crackling problem the the Cambridge Audio DAC?

 

My setup is very similar with a Mac-Mini feeding Beoport into a B&O masterlink Avant TV with B8000's at the front and B4000's at the back and a 3200 linked to B6000's. I'm sure a DAC could improve my sound quality but am concerned about your crackling.

Best regards,

Rob

London, UK

Hi Robyn

After weeks of going back to shop of where I bought the DAC, talking to B&O technicians (who basically said politely, no idea) the solution was found through a very experienced professional music equipment supplier in Sydney.

The solution was as simple as turn down the volume to about 2/3 or half way on itunes itself!!!! It appears itunes, beoport and the DAC were all amplifying the signal. If this doesnt make sense..email me back at boyuk@ihug.com.au

The DAC will greatly improve the sound of both netradio and net music

 

Good Luck

David Coyne

Sydney, Australia

Hi David,

Thanks for the quick response. I'm very encouraged to hear the fix is simply to lower the output volume, this does make some sense in that if everything in the chain was amplifying the signal it would/might overload the BeoPort input.

I'm very interested in improving the quality of the sound as I love using my Mac to serve music and movies around the house but have found the sound a bit "flat" when taking the analog audio output of the Mac directly into the BeoPort.

I'll be ordering a Cambridge Audio DAC shortly!

Best,

Rob

Hi David,

Last night I connected my new Cambridge Audio DACmagic between the Mac-Mini and BeoPort.

 

WOW what a revelation and it's only just started "burning-in"

 

The whole sound has improved considerably. Bass is tighter, mid-range clearer and the highs are really crisp.

 

One thing though, I did find the USB connection an improvement but still a bid muddy at the lower end so tried a fibre optic cable instead and then the sound was absolutely perfect. Worth considering.

Best,

Rob

hi all,

i am intrigued by the use of a dac. i too have a mac mini as a music server...

can you tell me a little more about what "happens" when you connect the dac to a mac mini via the usb port :

• is it configured as an external sound card by the mac ?
• is it os dependant ?
• is the headphones out jack on the mini disabled ?
• can you tell me more about "the dac can be easily turned on and off using the computer"

Hi All,

 

I love the DacMagic - its lifted my music collection no end!

The problem I have is that I've placed it in a cupboard so have to go in an turn it on everytime I listen to iTunes over my Airport Express.

This is especially annoying when listening to iTunes in a link room since the cupboard is in the living room.

Does anyone know of a way to switch it on and off remotely? I got so used to hitting a button on my Beo4/5 + play on my Macbook Pro = music!

 

I do not own a DAC (I would love to have one, though), but I use an "intelligent" power plug for similar uses.

It has a master power plug and several slave power plugs. I plug the mac into the master and all other devices into the slave power plugs.

My power plug has a potentiometer with which I can adjust the threshold to exactly the power the Mac is drawing when in operation. Thus, when I switch on the Mac, it draws more power than in Standby mode. Once the intelligent power plug recognizes this, it provides power to all slave plugs.

oh my,

that's clever. where can i find out more about this, do you have a favorite brand, or supplier ? thanks...

 

scott

I've spoken to my local Hi-Fi dealer and he tells me its actually best to leave a DAC on all of the time. He said that it actually needs a couple of hours to warm up to give optimum sound so leaving it on is a better.

He also said that, in the case of the DacMagic, as the psu is external there is no danger to the device if it blows or anything.

I plan to write to Cambridge Audio to confirm this.

In the mean time, can anyone corroborate this?

Scott,

This is the Master/Slave Power-Plug I am using:

http://www.conrad.ch/goto.php?artikel=059713

STEBA Vario mit einstellb. Schaltschwell (Conrad Electronic)

This is a Swiss product, it costs about EUR 60.

I am not sure if you can obtain it in France, too. I am sure there must be similar products with the same functionality.

(Please read also the post of the user proposing to have the DAC always on)

Crackling from USB ports to DACs, and not just Cambridge's, is due to the USB ports on the Macs. Since you're using USB for both your connections, David, you're bound to have one "lousy" port. It's thought to be a result of interference from keyboard USB interface.

Usually disappears if you switch the USB connector to the other USB-port. Would like to suggest that you use the toslink optical out for your other connection, once you find which USB port does not create distortion.

Make certain that you have the sample-rates, etc. set up right in Audio MIDI Setup.

You shouldn't need to reduce the volume output, but if it works then go for it.

But the USB port issue is well known, and should resolve things for you.

 

Check out this link for proper set-up:

http://extra.benchmarkmedia.com/wiki/index.php/OS_X_Audio_Playback_-_Setup_Guide

Here's a little on the USB port problem. There are various other articles on the net on this. Depending upon the hardware configuration, it's the left or right port, or the rear or front port of your Mac. You can map this differently, but just switching ports solves the problem:

http://createdigitalmusic.com/2009/04/27/mac-usb-audio-woes-m-audio-says-avoid-the-left-hand-usb-port/

And just leave the DAC on, no need to switch it off. I've had my DAC on for about five months now without interruption, and it doesn't use a lot of power.

Good luck!

 

The use of USB Audio Devices on the Left-Hand USB Port Is Not Recommended.  This applies to ALL MacBook Pro Models (Core Duo and Core 2 Duo).

•    The 15" MacBook Pro models have 1 USB port on the left side, and one USB port on the right side.
•    The 17" MacBook Pro models have 2 USB ports on the left side, and one USB port on the right side.

Due to the current USB configuration of the 15" MacBook Pro under OS X, use of USB audio devices is supported on the right-hand USB port only.  Use of such devices on the left-hand USB port(s) is not advised because it may cause audio interrupts and/or dropped samples.  However, the use of an iLok on the left-hand port has been qualified and is fully supported.

Due to the current USB configuration of the 17" MacBook Pro under OS X, use of USB audio devices is only supported on the right-hand USB port, and the left-hand USB port farthest from the screen.  Use of such devices on the left-hand USB port closest to the screen is not advised because it may cause audio interrupts and/or dropped samples.  However, the use of an iLok on the left-hand port has been qualified and is fully supported.

These USB port recommendations are specific to USB Audio devices only (such as the FastTrack USB or Audiophile USB).  USB Keyboard and Control Surface products do not have a recommended USB port at this time.

 

Hi there,

I'd agree with the hi-fi dealer, the DAC sounds much better when "burned-in" for a few days and then left on. It's also true for most electronic devices.

The small amount of power used is well worth the boost in sound quality

Best,

Rob

HI Guys

 

You know Ive done everything to try and rectify the crackling issue..including buying toslink cables and very expensive cables elsewhere...

I didn't however try moving the beoport usb connection to another usb in the mac... I'll try that. Could be a sneaky solution.

I'll also try leaving the DAC on..didn't realise it needed to warm up. Must train the partner to stop turning it off!!!!

Regards

David Coyne

Sydney, Australia

Hi All,

 

I've now had a response from Cambridge Audio regarding leaving the DAC on all the time.

 

The first point they made was that the DAC needs to be run in for 30-40 hours to achieve its full potential. After that, warming it up (leaving it on for a few hours prior to use) makes no difference.

Regarding leaving it on 24/7 - the response was a little more vague!

It was along the lines of 'all electronic devices will have a shortened life the longer they are used. It will also use more power that way'!

Not sure that really helped much! I guess they're trying to say that you can leave it on if you like but we've warned you that it might not last as long if you do

Which would bring us to the question of what lifespan we expect from our electronic gadgets.

I for myself am very happy to report that I have my BS9000 in operation for ten years now - I am using it almost every day, at least every day I am at home. I am happy with this and see no point in exchanging it.

Whereas when it comes to digital media, I seldom use a device more than two years - after that it will be replaced by a newer device that follows technical progress.

One could also argue that switching on-and-off a component will heat and cool it every day, ensuring greater wear from expansion and contraction, rather than having it at the same temperature.

What's important is that it's placed somewhere it doesn't overheat, not in a closed, small box, for instance. My Mac mini has been on for two years now ... My ReadyNAS+ NV showed 14.000 hours of running time last I checked.

 

 

Hello All

Changing usb connection between the mac and beoport didnt make any difference re the crackling.

So im back to having itunes on at about 3/4 volume. Interstingly there was no crackle until the DAC was connected.

Other connections are toslink..mac to dac

All operations in itunes are off- i.e equaliser and enhancer/sound check

I may just need to accept this is an unsolved mystery...?????

Still the DAC has improved the quality of sound from my digital files greatly.

Soundproof..any other ideas? Does it really matter that itunes volume is not on full? Is this going to effect overall sound quality?

Regards

 

David Coyne

Sydney, Australia

Level of volume out is not an issue with QuickTime 7 and 8, and I'm guessing you have QuickTime 8 - so no need to worry about that.

I'm guessing that the increased volume raises the V RMS output through the analog connection to a level that the speakers can't handle. On my BL5s this should be less than or equal to 2 V RMS. As a general rule, when connecting to non-B&O equipment, it's wise to start with the volume low, and then find the best level.

I just checked the output level of the DacMagic. I take it you're using the unbalanced RCA outs? These are rated at 2.1V RMS, while the balanced outs are rated at 4.2V rms - if you're using the latter, then you should get crackling! Way too much for the speakers, and it would explain why you have to turn down the volume.

Which output are you using?

Hi Soundproof et.al

Sorry for the slow reply...

I have checked the connections and Im using the unbalanced RCA outputs. So still dont understand why I'd get crackling when itunes volume is turned up to full.

I'm assuming it must be to do with the beoport amplifying the sound as well????

Toslink and good quality cabling is being used. Ive tried different usb connections from the mac mini, that doesnt change the crackling either.

It is mysterious isn't it??!!!

 

David Coyne

While replying to some other threads, and considering a DacMagic myself...

I have a painfully dumb question for you folks!

My iTunes library is several years old (~7ish). When I first started using it and ripping/dloading music to it, I frankly never paid much attention to the rip rates as the content was almost exclusively used on iPods. FFWD a few years and connecting to other devices, I have started being more careful to rip using much higher quality. The problem now is my library (~20,000 tracks) is a hodge-podge mix of music at all different rates. Short of starting from scratch (not going to happen), might the upsampling from an external DAC turn my oldest, lowest quality rips into something perhaps respectable? What should I expect?

Thanks in advance!

It's not going to improve the end result, more likely just makes it worse. Since the compression is lossy, the damage was already done when the original full quality rip was compressed to the bitrate you have in your files now. If you now decode the music and then recompress again, it will be altered once more and it will only get further away from the original data.

I would rip again those files that are annoyingly low quality (and easily available), and just leave the rest be. A rerip will probably take much less time now than it did 7 years ago

david coyne:

Hi Soundproof et.al

Sorry for the slow reply...

I have checked the connections and Im using the unbalanced RCA outputs. So still dont understand why I'd get crackling when itunes volume is turned up to full.

I've had this problem numerous times with artists and laptops being used on stage. In those situations, the 'crackling' sounds like a low rumble with a high-pitched noise on top of it, the higher pitched noise responding to the activity of the hard drive. In those cases, the 'crackling' is always audible, no matter the volume setting on your sound card or if there's any music playing.

It's being caused by the power supply of most laptops (and the Mini), which is a switch-mode and doesn't care about leakage currents to ground. Combined with longer RCA cables and/or ungrounded Beosystems, ground loops will crank up the noise level consderably.

The easiest way out is galvanic separation: Connect your Mac Mini to a DAC via a S/PDIF optical cable, not a coaxial one or USB. The Mini has a TOSlink output socket on the headphone jack.

 

If the 'crackling' is only audible when the iTunes volume is all the way up and your music has loud passages, that means either your DAC output or the Beosystem input is clipping. Simple remedy: Reduce the volume.

david coyne:

 

Hello All

I have recently purchased a DAC by Cambridge Audio

http://www.cambridgeaudio.com/assets/documents/DAC_Magic_rear.jpg

I was quite unhappy with the sound of some of my digital music libray, even some of it being at high bit rates or 320 or lossless.

My digital library is on a mac mini. I also have beoport, beocentre 2 socket box and beolab 9 speakers.

The set up is as follows:

USB from MacMini to BeoPort

USB from MacMini to DAC

1/4 inch headphone jack from DAC to BeoPort

Essentially the DAC is used as an external sound card whilst retaining the functionality of the BeoPort.

 

Hi all, just bringing this thread up again, i will have a very similar setup soon, (however i'm considering using beoport with BC2 with a desktop iMac)

i wanted to know if this setup with a DAC and beoport can be connected via an airport express (so i don't have a usb and headphone cable runing through my livivng room)

 

Any suggeastions??

k984942:

Hi All,

 

I love the DacMagic - its lifted my music collection no end!

The problem I have is that I've placed it in a cupboard so have to go in an turn it on everytime I listen to iTunes over my Airport Express.

This is especially annoying when listening to iTunes in a link room since the cupboard is in the living room.

Does anyone know of a way to switch it on and off remotely? I got so used to hitting a button on my Beo4/5 + play on my Macbook Pro = music!

 

A very good solution comes from Germany: The Lightmanager PRO from JBmedia.

It allows you to control remote sockets via Beo 4 and Beo 5. It's not only intended for lightning control, so I used it to control lights and for example switching on/off the power amp of my subwoofer.

Have a look:

http://cms.jbmedia.de/index.php?option=com_content&task=view&id=95&Itemid=74

NOTE that you have to use the Lightmanager PRO B&O version!

Online shop:

http://cms.jbmedia.de/index.php?option=com_wrapper&Itemid=8&lang=en