Adventures in computers as transports

[nb2]

With the greatest of respect to the dealer involved - He would say that. They're not selling Beresford DACs and they certainly wouldn't say that a £150 product beats any of theirs costing £1000.

I know my subjective opinion is as invalid to you as anyone else's, but I would beg to differ. I've spent 10 years in good quality hi-fi retail and I could count the amount of digital products I heard in that time that sound better than my 7520 on one hand. Every single one of those products commanded at least a 4 figure sum.

One thing we might not have touched on is to ask what digital interconnect you are using between your SB3 and your 7520? The only reason I can think of (barring your amp and speakers not being revealing enough to show you the differences - which they should be) is the quality of your coax/optical cable.

I noticed in an earlier thread you said you found no differences between optical and coax.. Which cables are you using? I ask this because when I first bought my 7510 I already had what I thought was a decent optical cable to go between my Mac and DAC. It was an IXOS cable I spent a bit of money on a few years previously, but Stan's cable was very reasonably priced and I needed a spare.

I was extremely glad I bought it, as my IXOS cable made the 7510 sound unbearably bright and hard. The difference between that and Stan's optical cable was astounding and if I hadn't been able to compare the two side by side, I'd never have thought such a difference possible.

I'd say if you haven't got one already, you owe it to your 7520 to feed it with the best quality digital interconnect you can find.

Well no problem, this is just a matter of personal taste and feelings.
Anybody can be satisfied with whatever product he feels like.
I just give my opinion in case someone is interested :-)
As far as my dealer is concerned, our conclusion came only from what BOTH of us heard ...

I just don't subscribe to the way some people rate different dacs, but I have no problem with that ...

What I can say so far is

- I got excellent results with the squeezebox on a decent system, and I really consider the squeezebox is an excellent value for money (as a dac, and it gives much more than a dac).
- I got slightly better result with the TC-7520 on the same kind of system.
- I got much better results with CD players and other dacs on the same kind of system (and I have several others to try).

Up to now, on my system, compared to all sources I tried, including Squeezebox and TC-7520 LM4562NA, my dead old CD player was much much better, without the slightest hesitation.
I think it is useless to search in the Dac Magic price range.

Now, people can perfectly think that when a TC-7520 doesn't spank a squeezebox, or doesn't sound almost as good as higher end dac, this is due to the power supply, the op amps, the amplifier, the speaker, the cables, the transport or whatever else you can think of ... which prevent the TC-7520 to show its qualities ...
Note that you could also think that when someone says that the squeezebox is just "Great to play though a high street electrical shop mini-stack", or when the high end dac is only marginally better than the Beresford, it could simply be because you didn't spent weeks finding the right setup for the squeezebox or the high end dac ...

Every serious dealer I spoke with, think that Dac Magic is not in the 1000 euros dacs league, and is a good "multimedia" dac.
I agree.
I don't find the TC-7520 vastly superior to the dac magic, may be sometime different, but not really "better".
I cannot consider a dac "spanks" another one, if it takes me some time to notice I accidently left my amplifier on the SB3 input instead of the Beresford input, on my system, with my cables.

You asked about my digital cables.
At home all cables I use are bluejeanscable, at least 1.5 meter length for digital.
Shorter digital cables are apparently known to be the source of reflection problems.
Up to 5 meter, with decent cables, there should be no length problem.
And most high end digital cables comparison I heard of, used shorter lengths, one meter or less ... so are they relevant ?
When I wrote I found no difference between optical and coax, I was only talking about the TC-7520 with bluejeanscable optical and coax connected to the squeezebox.

If you need to spend several times as much as the dac in power supply, op amps, digital cables and so on, to see its qualities, as far as I am concerned, I'm pretty sure I'll spend more in the dac and keep my bluejeanscable ...

I think the digital treatment to the data sent to the dac is much more important.
For example, you wrote somewhere that the Playstation 3 was a bad transport for you.
Are you sure you configured it with the correct settings ?
If you let the playstation convert everything to 48 Khz (I think it is the default setting), no need to say that comparison with another transport is useless ...

I'm interested in your results since your system seems really good, and should show differences in dacs qualities.
The squeezebox classic is quite cheap.
I think you should really try it.
It is an easy way to suppress most problems you can have with softwares or drivers which can silently resample or transform the digital signal.

[lovejoy]

As far as my dealer is concerned, our conclusion came only from what BOTH of us heard ...

I just don't subscribe to the way some people rate different dacs, but I have no problem with that ...

To go back to answer your original question in the previous thread, I would say "Yes", there is something amiss somewhere, but I think we've reached a point where without being there to hear what you're getting it's pretty much impossible for any of us to help troubleshoot from a distance, but I think I can speak for the vast majority of 7520 owners here when I say yours and your dealer's findings are in stark contrast to the rest of us here.

The reason I bought a 7520 was because I could hear a significant difference between that and my 7510, even with the 7510's uprated op-amps and super-duper power supply, so I'd put money on the difference between 7520 and stock SB3 being bigger than that, given that there are no other limitations in the system.

What I can say so far is

- I got much better results with CD players and other dacs on the same kind of system (and I have several others to try).

I'm really interested to know what these are. Any chance of a rundown?

I think it is useless to search in the Dac Magic price range.

Completely agree with this point.

Now, people can perfectly think that when a TC-7520 doesn't spank a squeezebox, or doesn't sound almost as good as higher end dac, this is due to the power supply, the op amps, the amplifier, the speaker, the cables, the transport or whatever else you can think of ... which prevent the TC-7520 to show its qualities ...

This is a perfectly reasonable assumption to make. A large percentage of the cost of what goes into making a high end piece of digital equipment is the power supply, then the op-amps. The DAC chip itself costs relatively little. To this end, Stan Beresford has designed a fantastic piece of equipment within a budget constraint and actually encouraged people to have a go at optimising the system by the use of better power supplies and op-amps etc. You have the choice of doing this, or you could just spend a lot more money at the outset and get a solution where all of this has been taken care of for you. From a dealers point of view, the latter approach is far more attractive as the problems that the former poses make the whole thing more trouble than it is worth. I chose the former as I'm a bit of a geek and I've learned a heck of a lot and have enjoyed every minute of it. The rewards of this time and effort (of which there has been a lot) are now paying dividends in how utterly amazing my system is sounding.

Every serious dealer I spoke with, think that Dac Magic is not in the 1000 euros dacs league, and is a good "multimedia" dac.
I agree.

'Serious dealers' are prone to a modicum of hi-fi snobbery, certainly where Richer Sounds products are involved - I know, I've been there and got the T-shirt. I've not heard the DACMagic so can't comment on how well it compares with the Beresford, but to dismiss it as merely a 'multimedia' product sounds lazy and smacks of 'we don't sell it, therefore it can't be that good' mentality that many dealers are guilty of. I'm willing to put money on the fact that at least one of the dealers you've spoken to has never heard it either.

Up to 5 meter, with decent cables, there should be no length problem.
And most high end digital cables comparison I heard of, used shorter lengths, one meter or less ... so are they relevant ?

I've read that when using coax digital interconnects 1.5m is a good length to avoid signal reflections, but that doesn't automatically mean that anything shorter will not be any good. I heard a Siltech cable going back a few years which was only 0.5m and that was quite amazing compared against a decent budget cable. Longer lengths will introduce problems other than signal reflections so I've always stuck to between 1 and 1.5 metres. Whilst optical cables don't suffer from signal reflections or electrical noise, I'd still stick to under 2m lengths. But that's just me.

If you need to spend several times as much as the dac in power supply, op amps, digital cables and so on, to see its qualities, as far as I am concerned, I'm pretty sure I'll spend more in the dac and keep my bluejeanscable ...

You pays your money, you takes your choice. That extra money you spent will have gone into more expensive power supplies, op-amps etc.

I think the digital treatment to the data sent to the dac is much more important.
For example, you wrote somewhere that the Playstation 3 was a bad transport for you.
Are you sure you configured it with the correct settings ?
If you let the playstation convert everything to 48 Khz (I think it is the default setting), no need to say that comparison with another transport is useless ...

Absolutely 100% agree with you.

I spent a while playing with the PS3. In it's stock form, I tried every possible output frequency. Whether that was default setting, native CD, or upsampled, the results were very poor. Then I tried installing Ubuntu and ripping some CDs losslessly and setting up the audio output for 16-bit 44.1KHz, but apart from not sounding any better, ran Ubuntu painfully slowly, so it wasn't really a good solution.

I'm interested in your results since your system seems really good, and should show differences in dacs qualities.
The squeezebox classic is quite cheap.
I think you should really try it.
It is an easy way to suppress most problems you can have with softwares or drivers which can silently resample or transform the digital signal.

The Squeezebox has tempted me a number of times. I have been very close to buying one, but I'm so happy with my PC setup now (which I am about to elaborate on), that the need for one has suddenly vanished.

I think from all of this you have drawn a good conclusion, i.e. that in order to seriously improve what you've got already, you're going to need to throw a not insignificant sum of money at it. It would be really interesting to know what route you choose.

[lovejoy]

Well I am full of the joys of spring this morning.

I've been wondering for a while now why it is that so many pieces of software claim to be 'bit perfect' i.e. they're not messing around with your audio data at all and yet they all sound different to me. Well, I think the answer came to me in last night's experiments.

I have been playing with 'Jack' as I mentioned in my previous post under Ubuntu (other Linux flavours are available). Jack is meant more for recording music than playing it back, in that it provides a low latency audio layer which is critical for people using their computers as recording studios.

However, Jack has a little checkbox marked 'Realtime' which also works in playback. Whereas your 'bit perfect' should ensure the same bits that came off the CD reach the DAC, 'Realtime' ensures they do so when they should. I had often wondered how, in a computer system, audio was dealt with in a way that delivered data to the digital outputs with the highest priority, above all other tasks as a time critical operation. When you think how an operating system has to deal with a million and one tasks and divide its time between each and every one of them, it's amazing that they can manage to deliver audio at all, and I think this is the fundamental issue that separates them. 'Bit perfect' is not enough. Timing accuracy is equally, if not more important, and from what I can gather at the moment, not all OS types are capable of real time audio handling. Hence, different systems, different sounds.

The guys who developed Ubuntu Studio clearly already know this as a lot of this is set up out of the box. I just took the long way around and did it all through a standard Ubuntu install .

You know when your system is doing something really special when:
1. You've got a massive grin from ear to ear with everything that you play and constantly utter the phrase 'well I've never heard it like that before' after every song, and
2. You can't play it loud enough.
So I must apologise to my neighbour's dog on that front, thankfully the neighbour's themselves had popped out.

I've arrived and I'm absolutely chuffed to bits about it. All this time and effort spent is now being well rewarded and I'd recommend to anyone wanting to dabble, a full digital front end that you can setup for not a lot of money:

A nice small form factor and quiet PC, something along the lines of a Dell Optiplex that you can get off Ebay these days for around 65-100 pounds. Install Ubuntu Studio on it, rip all of your music onto it, plug that into a 7520, put that into your amplifier and be thoroughly blown away.

OK that maybe over simplifying things a bit, but I'm happy to help for anyone stuck following this route. Maybe I should set myself up with a sideline in selling and installing such things .

[Tony Moore]

Hi Rich,

Interesting post. Do you connect from your Linux PC to TC7520 using USB or s/pdif?

Have you tried both?

Cheers,
Tony
ps. I think around 1m length s/pdif electrical is the length to avoid as it puts the reflection's timing close to a multiple of the clock rate (for 44.1Khz sampling/32bits) making the clock recovery PLL work harder and therefore potentially introducing more jitter. 0.5m should be ok, as should 1.5m+. This would be different for 48Khz and/or different bit depths of course. I've not done the calculations myself though so this is all 2nd hand info!

[lovejoy]

Hi Tony,
I am using USB at the moment, which in a previous listening test I preferred over both optical and coax. Not a night and day difference, just better focus.

I'd like to try the other connections again, as the limitation with the USB connection is that I can't play my 24/96 content without downsampling it.

When I can get the digital output on my soundcard working under the current Ubuntu build, I'll give it another go, but until then, not hearing the very small handfull of 24/96 material I own is a very small sacrifice.

[leo]

Does the USB interface chip for the 7520 supply the dac chip direct like I2S or is it used to output spdif ?

[lovejoy]

Hi Leo,
From what I can gather, there is a little daughter board that sits above the USB socket that has a crystal and a USB -> I2S converter IC (can't remember the device name as I don't have the DAC to hand) which feeds the DAC chip directly.

Stan might be along to correct me on this though...

[nb2]

To go back to answer your original question in the previous thread, I would say "Yes", there is something amiss somewhere, but I think we've reached a point where without being there to hear what you're getting it's pretty much impossible for any of us to help troubleshoot from a distance, but I think I can speak for the vast majority of 7520 owners here when I say yours and your dealer's findings are in stark contrast to the rest of us here.

I think there is a misunderstanding here.
I already said that in my opinion, it is not the TC-7520 which is bad, it is the SB3 which is good.
Correct me if I'm wrong, but it seems to me that you never tried the Squeezebox (neither as a dac nor as a transport for the Beresford).
So it is more "the rest of them", than "the rest of us"

I'd put money on the difference between 7520 and stock SB3 being bigger than that, given that there are no other limitations in the system.

Well, personally, I don't bet, I try ...

I won't tell anything about the TC-7510 alone, or compared to anything else, I never heard it.
Even if it is much easier than with any other software (the operating system doesn't matter), you have a few things to check if you want to have the best result for the squeezebox.
Of course make sure you use lossless 44.1 flac or wav carefully ripped.
Make sure you correctly configure the analog output with 100% volume and no attenuation (correct settings can be found on slimdevices forum).
I am not sure those who claims the squeezebox is not very good, really used it at its best (and I guess some of them actually never tried it ...)
But for them, if the TC-7520 is not astounding for me, I obviously have a wrong setup for this dac ...
Add also that it seems to me that the TC-7520 output is slightly louder than the Squeezebox one, which is a well known reason to subjectively improve perceived quality.

On another forum, I contacted privatly two members who said their Beresford is very good improvement over the Squeezebox

- The first one told the difference is there (I agree), but that anybody claiming it is "night and day" is not serious (I agree too).

- The second confirm that the Beresford is much better than the Squeezebox.
But ... his beresford is now for sale ... and he ordered a dac magic, not a 4 figures priced dac ...

All in all, I am far for being the only one with my findings.
And others could as well have used the Squeezebox with a not so good setup.

I'm really interested to know what these are. Any chance of a rundown?

I had a Kenwood CD player bought I think in 1987
Not cheap, but something a student could afford.
May be a DP 3010, but I am not absolutely sure, it finally died, and I don't have it anymore.
When I replaced it, that was a night and day difference, in the wrong way ...
I have now upgraded up to the TC-7520 LM4562NA, and I am absolutely positive about that, I still don't get back 10% of what I lost ...

May be those 10% are "night and day" for many people, but when you know what this old Kenwood could do ... may be those people simply don't know there is much better.

I chose the former as I'm a bit of a geek and I've learned a heck of a lot and have enjoyed every minute of it. The rewards of this time and effort (of which there has been a lot) are now paying dividends in how utterly amazing my system is sounding.

No problem, especially if you enjoy it.
But upgrade whatever you want, at some point, the dac chip will be the weak link, and you will have to change it.
There is a point where you might as well build entirely your DIY dac (or directly buy a higher end one).

'Serious dealers' are prone to a modicum of hi-fi snobbery, certainly where Richer Sounds products are involved - I know, I've been there and got the T-shirt. I've not heard the DACMagic so can't comment on how well it compares with the Beresford, but to dismiss it as merely a 'multimedia' product sounds lazy and smacks of 'we don't sell it, therefore it can't be that good' mentality that many dealers are guilty of. I'm willing to put money on the fact that at least one of the dealers you've spoken to has never heard it either.

"Multimedia" means in comparison with high end audio dacs.
In my opinion, and in theirs, it is not pejorative, it simply means they are not in the same league.
All dealers I know who commented the Dac Magic with me, actually sell it (and yes, listened to it also).
In fact I think all dealers I know, are honest enough to say it when they never heard a product, and so say they cannot give their own advice ...

I heard a Siltech cable going back a few years which was only 0.5m and that was quite amazing compared against a decent budget cable.

What I mean is that if you use short length, you are likely to have reflection problems requiring a good and expensive cable.
If it is long enough, no need to spend unreasonable amount of money, a decent cable should be enough.
So one should feed his dac with a cable (decent or xxx high end) long enough, in order to get the best result.
In my opinion, bluejeanscable are good, it is not cheap spaghetti.

The Squeezebox has tempted me a number of times.

Once again, considering all transports you already tried, if you never heard it, you should really try the Squeezebox classic at least as a transport.
Get a second hand one if you want, it is cheaper than a TC-7520 ...
I bet you will stop loosing time with questions about OS, drivers, usb cable, and you could move that ugly PC far away from your system.
(Ethernet is perfect over 100 meter length and everything about music starts in the squeezebox)

[lovejoy]

Once again, considering all transports you already tried, if you never heard it, you should really try the Squeezebox classic at least as a transport.
Get a second hand one if you want, it is cheaper than a TC-7520 ...
I bet you will stop loosing time with questions about OS, drivers, usb cable, and you could move that ugly PC far away from your system.
(Ethernet is perfect over 100 meter length and everything about music starts in the squeezebox)

I don't consider that I have lost *any* time. This has been a learning experience, I have managed to answer a lot of questions I had about how computers deal with audio along the way and came out with some very surprising answers. The whole experience has been frustrating at times, but mostly enjoyable and the rewards will, and indeed are now far outweighing the time and effort spent.

As for the ugly PC, I may replace it with a smaller box at some point, but ugly though this one is, it allows me to use Spotify, Last.FM, BBC iPlayer for radio, MySpace for seeking out new bands, and countless other things. There is no more comprehensive route for discovering new music.

I think if the chance to hear a Squeezebox appears, I will jump at it, but at the moment, I have no further need to spend money on audio equipment.

[Maximum]

It seems we had a very similar weekend last week lovejoy.

After reading what you had put about linux I decided to try and revive my ubuntu partition into working order and got the sound working through usb to my 7520. To be fair I still preferred the foobar/ASIO combination as it seemed to have more depth.

I started looking into distros concentrating on audio usage, finding Musix, 64studio, and Ubuntu Studio. Musix was a large download and going slow, 64studio ran but I got annoyed with the ntfs access issues, so Ubuntu Studio is currently installed. Sound seems to be working well through Jack, but I get dropouts with the generic kernel and the realtime kernel crashes after about 10 minutes.

It was really odd though, as every time I read this thread you seemed to have done the same playing I had just done.