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Filterlab
29-01-2008, 15:28
Well, got the process rolling. My initial testing was on Sunday when after wiping down my iTunes and ripping 30 or 40 CDs in lossless format (AIFF on the Mac) I tried connecting my Mac's audio out into my passive pre-amp. Mmm, not good really. So I decided to go direct from the audio out into my power amp. Better, much better actually, in fact better than the A3.5 and the passive combination. So much so that I put my A3.5 straight on ebay and sold it on the Monday. :)

So, first thing is to get a proper DAC sorted as just the economies would indicate the DAC in an £850 computer is not going to on par with a dedicated external DAC for £1000. If you've been following the threads on here you'll know that I'm opting for the Benchmark DAC-1 USB as used in Robson Acoustics' demo system:

http://www.pincha.com.tw/catalog/images/benchmark-dac1-usb.gif

Since the input to a DAC is 1s and 0s regardless of which digital source it arrives from, the lossless files from the computer should theoretically be completely unhindered by any mechanical interference. Certainly Robsons' demo system proved that it could better a £2K SACD player by some margin. From there it's a case of simply changing my power amp to a pair of the NuForce Reference 9 monoblocks when funds allow (£980 each). There's no need for me to get the pre-amp as the DAC-1 has a variable output control built in. It also has three fixed output gain settings for straight through use, but I've a feeling that using my passive will only hinder it.

http://www.positive-feedback.com/Issue26/images/Ref9SE_2.jpg

Anyone else ditch CD for lossless?

SolidState
29-01-2008, 16:22
Hi,

I've ditched CD for lossless very recently, all my music is on 2 external hard drives, now i'm looking to buy a new samsung 1TB drive. I'm using a RWA squeezebox. Bottomline I won't be going back to CD.

Nothing wrong with digital per se, it's the implementation that has been flawed i.e CD players, hard drive digital playback is a better implementation of the digital format, especially when SSD's* become more widespread.

* Solid State Drives

Steve Toy
29-01-2008, 16:35
I'd like to welcome Robson as the first dealer I've ever encountered who has embraced this format for the future.

I really enjoyed the demo at the show and if I can get better music from a PC or laptop into a separate DAC then I'm prepared to sell my £2k Linn CD player and use whatever I get for it to (part) fund the necessary hardware.

I have to confess that I'm pretty clueless as to how it all works and will welcome some pointers in the right direction.

I can see a trip to Penrith coming up in the near future.

Filterlab
29-01-2008, 16:42
Glad you've the same findings as me, I should have guessed by your username of course! :D

Even the standard iMac output is very good indeed.

Robson
29-01-2008, 16:51
Hi Steve and thank-you for the welcome......any help I can give regarding computer audio, just ask.
I am also finding the importance of the pre-amp in the chain to be undervalued.

Steve Toy
29-01-2008, 17:15
I am also finding the importance of the pre-amp in the chain to be undervalued


I've believed for a long time that an active pre is better than going direct from source to power amp.

Robson
29-01-2008, 20:58
Hi again Steve......pre amps using with digital power amps is a tricky one and if I didn't own a Nuforce P9 I would use a valve pre how-ever I havn't found a better pre than the P9. If any-one wants a recommendation for a good valve pre to go with digital power amps then the Vincent SA-T1 at about £799 is wonderful.

Steve Toy
29-01-2008, 22:25
I'm currently using a Spectral DMC-15 which is a very good solid state preamp. It is also a sizeable piece of real estate so I'm wondering what I could swap it for in valve terms. My ideal valve pre would lean towards incisiveness over warmth. The power amp, a brand new Densen B-330(B) is slightly on the warm side but with bass authority/drive and kick to die for. I want to keep it and possiblty pair it with the right match of a valve pre.

Oh dear, I've gone off topic.

Lowrider
30-01-2008, 11:49
I have been looking into this subject lately, like to be always prepared for the next move... :rolleyes:

My requirements where a DAC/Pre with remote volume, preferably analog, and at least 2 optical inputs, to avoid noise from PC and satellite box...

Very good sound, of course...

It would be nice if it accepted DVD DPS and AC3...

The best I found are discontinued, Audio Aero Prima and April Stello DP220...

BelCanto DAC3 and the new Benchmark Pre/DAC1 are not bad...

As I use active subwoofer, bass management is also important for me, so I guess the solution in the end will be a good used AV processor...

Filterlab
30-01-2008, 12:26
...so I guess the solution in the end will be a good used AV processor...


I think Lexicon may be the answer for you. I've heard the TOTR HDMI one and it's an absolute belter. CAn't remember the number but I'll rack my brains. :)

Lowrider
30-01-2008, 12:41
This is still very premature, as my Linn is a player/processor, and I still have the Krell Showcase processor in Portugal, both sound very good...

Just someone heard and wanted to buy my Riga system, so I started "dreaming" with the next one... :cool:

max-greece
30-01-2008, 14:10
I have used loseless compression for a while now - on my phone. I have a Windows smartphone and was amazed to discover (by accident) that its media player actually supports WMA Loseless. Files seem to be about 70% of WAV files and playback over headphones is indistinguishable to me.

Right now I have a 4 gig card in the phone and that allows me to carry about 15 albums around although there is other stuff on the card too.

I am sure this is the future but speaking as an audiophile it would be nice to have 96/24 or higher loselessly compressed onto some silent solid state device as an alternative to vinyl.

I dont really ever listen to digital on the main system as I gave up on CD / SACD et all some time ago.

Filterlab
30-01-2008, 14:58
I am sure this is the future but speaking as an audiophile it would be nice to have 96/24 or higher loselessly compressed onto some silent solid state device as an alternative to vinyl.

The solid state drives are really starting to take off now, already the Macbook Air (http://store.apple.com/Apple/WebObjects/ukstore.woa/9534042/wo/PS1s0GdzU1VO2ArCny31dvSweuY/2.?p=0) has a 64Gb solid state drive and the drives will only increase in size. To be honest the difference between a hard drive and a solid state drive (in terms of sound quality) is negligible as long as both are performing correctly. Of course reliability is improved when moving parts are reduced (or better still eliminated) so that's another reason to adopt the technology.

I would say that there's plenty of space on a conventional hard drive for completely uncompressed audio files at 24bit/96khz, bearing in mind a Blu-ray disc holds 50Gb per side and can provide many hours of uncompressed audio and video. With that in mind a hard drive should be more than large enough especially now that 1Tb drives are available for very little money.

Vinyl Grinder
30-01-2008, 17:31
I've been intrested in FLAC for quite some time.

I do appreciate convenience most times, especially whaen i've had a drink & don't want to touch my precious vinyl! but just can't stand the sound of CD regardless what machine.So CD's are quite clearly out of the picture.What i'd be very intrested in is conecting my phonostage to PC as to convert the vinyl into FLAC files, using the files then for listerning.Ive actually heard a vinyl record put on to CD-r & could'nt believe the difference against the same commercial CD release.Although it's still a CD in copy it sound pretty much like vinyl all the same.This got me all excited to say the least.

So chaps whats the best way to go about it.Outboard processing 24/96 or sound card before amplification? (This is to be a serious set up not a PC based boys bedroom rig).

I got Dinosaur way to a certain extent chaps so go easy.

leo
30-01-2008, 17:49
I've been using a modified SB3 to feed an external dac for a while now, works great for me.
The SB3's are not that good as stock but are very capable once modified, most of my music is now saved as Flac,Ape and WMA

Filterlab
30-01-2008, 20:17
Ape? Not heard of that file extension before.

Mate brought over his Squeezebox this evening, and whilst I'm sure many will sing its merits, I wasn't impressed at all. In fact it sounded flatter than the standard Mac analogue output. :(

I'll stick with the Benchmark I think. Found a chap in Dorset who supplies studio equipment - has it for £880 inc VAT! Some places are asking £1030 so that's a bit of a saving. :)

leo
30-01-2008, 20:47
A standard Squeezebox will sound poor, it needs working on and even then its internal dac is no good so don't bother using its analogue outputs.
The psu and regulation is shit, lots of noise on the circuitry making it flat, the standard clock circuitry is poor, its standard SPDIF circuitry is poor, its basically cheap BUT has potential if you know what your doing and can make a fine transport if breathed on

Mines super regged, all the crap inside thats been made redundant is disconnected, improved clock oscillator and buffer, spdif circuitry modified and fitted pulse traffo on the output.
A digital co-axial lead feeds the external dacs

Filterlab
30-01-2008, 20:51
I think I'm too lazy to fiddle to that degree - plus I don't have a clue what I'm doing (to that extent anyway). I know it's a typical 'Londoners' response to just say sod it and spend five times the money buying something that will equal a modded component, but I'll say this:

Sod it, I'll spend five times the money buying something that will equal the modded component.

:D

Vinyl Grinder
31-01-2008, 03:37
Well, got the process rolling. My initial testing was on Sunday when after wiping down my iTunes and ripping 30 or 40 CDs in lossless format (AIFF on the Mac)

Anyone else ditch CD for lossless?

Rob seems AIFF is not a compression format AIFC is.also seems it takes more space compared to FLAC! AIFF is a very old format as well, around 1988 & is pretty much limited to mac users.I think im gonna stick with FLAC & it's totally free with virtually no red tape..So that's my lossless compression format sorted.

Filterlab
31-01-2008, 08:57
Rob seems AIFF is not a compression format AIFC is.also seems it takes more space compared to FLAC! AIFF is a very old format as well, around 1988 & is pretty much limited to mac users.I think im gonna stick with FLAC & it's totally free with virtually no red tape..So that's my lossless compression format sorted.

Indeed, however in my mind the more space a file takes then the more complete it is. There is Apple lossless as well but how it manages to reduce the file to half the size of AIFF without compressing is beyond me.

Also I edit all my pro work in AIFF as it still stands as the most flexible file format (even though it is limited to Mac - although I only use Mac so it's nay probs!). :)

max-greece
31-01-2008, 11:32
I saw some test recently that compared FLAC to WMA loseless and the basic conclusion was no difference in either compression or sonic result.

For me that means WMA simply because I have devices that play that back and not FLAC. I guess the reverse will be true for others and this is probably the way to choose your compression.

I did do a comparion of WMA loseless with MP3 @ 256 KB and there is a noticable difference between them. Not sure I have any rips that are actually better than the original CD though. Whilst this is probably not a surprise I have heard before people claiming digital copies are better than the originals. How that happens I have no idea.

Ripping from vinyl is where it is at for me - at least where it will be at when I get around to it. That will be very interesting and my soundcard (Soundblaster Audigy 2) supports ripping at 96/24.

Just need to get one of those 1 TB drives I guess.

Vinyl Grinder
31-01-2008, 14:25
Max:

WMA does sound better than MP-3 at max bitrate but it's lossy isn't it?

max-greece
01-02-2008, 07:52
There are 2 forms of WMA compression and one is actually loseless. Its called WMA loseless compression for a reason lol.

It is available in Media player (at least in the one I have installed).

Normal WMA @ 192 kb/s is on a par with MP3 at 256 or 320 IMO.

Ashley James
02-02-2008, 15:53
AVI is bringing out a very high quality Preamplifier with 4 digital and three analogue inputs as well as both digital and analogue outputs. It will also be available as an Integrated Amplifier.

There's a lot of crap talked about DACs, the one in an Airport Express may well be identical in specification to the one in a £15,000 player and both will cost £2-4 to anyone buying small quantities. DAC chip manufacturers provide copious instructions and often PCB layouts to manufacturers, some of who still get it wrong. And that's when they can even buy the finished article to learn from.

In other words how good a DAC sounds depends on how well its designer has read the instructions and carried them out. All we claim is that it's textbook, so as good as the technology will allow.

The sound quality of Digital devices is much better than it was but there are still lemons out there and price is no guide to a good.

Lowrider
02-02-2008, 16:00
The DAC chip is almost the less important part in a DAC, power supply, output analog section, etc, make a lot more difference in the quality of the sound...

Filterlab
02-02-2008, 16:19
The DAC chip is almost the less important part in a DAC, power supply, output analog section, etc, make a lot more difference in the quality of the sound...


Indeed, and the same can be said for the majority of hi-fi components. Good explanation as to why two CD players with the same Philips mechanism can sound so different.

SolidState
03-02-2008, 00:18
The DAC chip is almost the less important part in a DAC, power supply, output analog section, etc, make a lot more difference in the quality of the sound...

Indeed, this is why my squeezebox is powered by an Optima red top battery and so will be my next DAC.

tr@nz
14-04-2008, 02:09
Pardon my double posting, I just found this thread.

Thanks for starting this thread and the info. I have been spending many late nights researching and experimenting to ultimately reach the goal of better sounding music through a pc/mac music server versus a cd player. There are so many options, it is daunting.

Currently I have a Mac Mini, a Benchmark DAC1 (non-USB), a Squeezbox and a Native Instruments Kore (v1) unit to play with. I am using a Denon 2900 multi-player as a benchmark to all the various music server options. McIntosh pre and tubes are powering the speakers.

OS Type

Mac or PC is purely a personal choice on which OS you like better. I went for the Mac Mini as it was such a small, quiet, hide-behind-the-tv unit that will start playing music from sleep mode faster than you can put a cd in the cd player. And it can be accessed through a remote control (front row, Mac remote, Ipaq, iPhone etc.)

iTunes/CoreAudio Setting

For iTunes /Core Audio the 24 bit setting is a given and has been confirmed by many sources to give better results, however, after all the research I can still not get a definitive answer on whether upsampling up to 192Khz is better sounding. And which setting is the best sounding? Some say you need to be at multiples of 44.1, others (Benchmark Media) sample everything to 110Khz as they found that to give the optimal performance. Others say upsampling just adds more noise into the path and should not be done. Confusing!

Media Format

I have currently been ripping CDs to ALAC (Apple Lossless) as it seems easy to use, and from many different sources I read it is bit for bit the same as AIFF or WAV. It is just packed, analogous to a Zip file.

Of course there are many schools of thought, and I would love to hear a definitive answer.

Connection Type

To add more variables into the mix is the question of what connection to use which will result in the best sound; LAN, WLAN, optical fiber, optical glass, coax, USB, USB2, Firewire!?

Many threads will discount toslink/optical and WLAN for introducing too much jitter. Toslink/Optical is also maxed out at 24/96. USB is maxed out at 24/96. And the Mac does not have Coax. That leaves LAN, USB2 and Firewire from the MAC and Coax through from an external DAC.

The permutations are ear-numbing.

At this point I am thinking of getting the Apogee Mini-Dac firewire, so that I can set the iTunes/Core Audio to upsample to 24bit/192Khz, and return the Benchmark DAC1, retire the Kore unit (currently used to try the USB2 connection from the MacMini), and use the Squeezebox (used to test the WLAN, LAN connections from the MacMini) purely for internet radio.

Another option is to use the Apogee as the firewire interface at 24/192 and send coax to the Benchmark for D/A. The only issue I see from a theoretical standpoint is that a 16/44.1 recorded cd is upconverted by Apple's src to 24/192 to then be downconverted to 24/110 by the Benchmark.

What are the best options to obtain the best sound setup? What are the best DAC solutions out there, from money no object to slightly more affordable? Please share blind listening test experienes or shootouts with units such as Dcs, PS Audio, Apogee, Lavry, Mytek, Prism, RME etc.

Look forward to sharing the continuing quest.

Cheers.

Chris
22-04-2008, 21:28
Suggestions please on how best to connect my MacBook to my Suggie. First of all without an external DAC and later perhaps with one (which ?) if I really get into it. Is the phones output really line-analogue or digital depending on whether I stick an optical or a coaxial mini jack therein ? If so, how does it detect whether I need volume control or not through the analogue ? Am I thick or what ?
Thanks in advance for being gentle

jcbrum
22-04-2008, 22:17
Yes, :)

It's both depending what you stick in it.

The best output port for a dac/adc/soundcard is the firewire 400 or 800, it's fast and stable, and what the pro's use.

Consider a Yamaha GO44, £60 1394/Firewire.
STUNNING AUDIO QUALITY AND IT DOES 24/192 and S/PDIF Coax !

http://www.yamaha-europe.com/yamaha_europe/uk/30_computer_related_products/41_firewire_products/10_no_category/10_firewire_products/10_no_series/15_go44/index.html

Will easily beat a Benchmark IMO

There's over a hundred DAC/Souncard/ADC to choose from though.

Chris
23-04-2008, 21:22
Can you point me to one for 60 quid or was that a typo ? and while I´m trying
to locate one can I just use an analogue mini-jack to rca phonos to connect my Macbook to amp ?

Alex D
23-04-2008, 22:27
http://www.dvguitars.com/invt/33078/

Chris
24-04-2008, 08:50
Am I right in that I will be able to use the Yamaha to record my vinyls to digital 24/192 on my Mac HD?

Filterlab
24-04-2008, 09:32
Yep, it is an ADC as well as a DAC.

sastusbulbas
24-04-2008, 12:53
What internal and external soundcards output digital at 24/192? And what DAC's are available to utilise this?

Steve

Chris
25-04-2008, 22:36
So, I record my vinyls via the ADC in the Yamaha GO44 in 24/192 format onto my Mcbook HD. How do I then reproduce them ? via itunes through the DAc and into my Sugden etc., I assume.
My question is, and please remember I´m thicker than average, would I only get the advantage of the 24/192 recording where the yammie or similar were in circuit. What if I put such a recording onto my ipod ? or made a CD for my car - would this be reproduced as a run of the mill redbook CD ?

Filterlab
26-04-2008, 10:30
So, I record my vinyls via the ADC in the Yamaha GO44 in 24/192 format onto my Mcbook HD. How do I then reproduce them ? via itunes through the DAc and into my Sugden etc., I assume.
My question is, and please remember I´m thicker than average, would I only get the advantage of the 24/192 recording where the yammie or similar were in circuit. What if I put such a recording onto my ipod ? or made a CD for my car - would this be reproduced as a run of the mill redbook CD ?


Ok, record each track individually into Audacity (http://audacity.sourceforge.net/) or something similar. Audacity will accept any bit rate / word length input but will (I think) automatically convert it to 44.1Khz/16-bit. Once the track is recorded then save the file in AIFF format to the desktop and then slide it into iTunes and name it. Alternatively you can use WireTap Pro (http://www.ambrosiasw.com/utilities/wiretap/) and record it as it plays (in AIFF), although WireTap Pro does record all the system sounds too, so best to close any noise making applications like Mail and Safari, nothing worse than the 'bloop' sound of an email arriving half way through your favourite song. Again after each track has recorded, you save the file to the desktop and slide it into iTunes.

You can then burn as many discs as you like all in uncompressed AIFF. However, as iPods don't play AIFF (as far as I know) you will have to convert the track in iTunes to whatever format you usually convert to for your iPod. I'd have to have a look at the user settings for Audacity / WireTap Pro to check whether either are capable of recording at 24-bit word lengths, but to be honest the difference is marginal and the quality of the Yamaha DAC will render any potential improvement negligible. If you get stuck just chuck your question up on here, if you really get into a muddle I can do an instruction post in a similar vein to the audiophile settings one.

Hope this helps!

Chris
26-04-2008, 16:42
Cheers Rob,
I haven´t actually got my Yamaha DAC yet and so it will take a while for it to arrive from the UK to the Canaries but I shall get there and when I do, I will be bothering you again.
Thanks,
Chris

Filterlab
28-04-2008, 19:12
Bother me whenever you like mate.

I've since discovered that Audacity is capable of handling anything up to 48Khz and 32-bit, and I've also discovered that the iPod can support AIFF at uncompressed resolution albeit at the expense of hard drive space. :)

Shame they don't fit a digital output to it. :(

Peter Stockwell
25-06-2008, 11:16
Curiously enough, what started me looking at this thread is a Technics SL1210! The new SL1210 in my system has got me thinking about phasing out CD playing, totally, from my main rig.

So I'm looking for a solution that will at least match the sound quality of a Naim CDX/XPS. I can't move the omputer from the "computer" room, even it is a tiny mac mini. I have a 30Gb iPod with about 1000 ALAC files on it, and I have a basic iPod dock that takes the line out.

Let's say I wanted to be able to use a Macbook as an iterface to the hard drive attached to the Mac mini, how would I start about making the transition ?

Thanks for any suggestions

Filterlab
25-06-2008, 11:25
Firstly forget the iPod bit, it's nowhere near enough good quality to be exposed through a hi-fi. The Macbook on the other hand is a superb tool as a lossless audio server.

1. Start by installing Cog (for replay) and Max (for importing when you need to).

2. Create a copy of the music files stored on your mini (if they're lossless) on your Macbook.

3. Hook the Macbook up to an external DAC and go from the DAC to your pre-amp.

Connect the Macbook and the Mac-mini together via a Firewire lead, the mini and the book should immediately see each other as another device and it's only a case of dragging files across - no network wizard bollocks, no installations, no hassle. :)

Peter Stockwell
25-06-2008, 12:04
Rob,

Thanks, that's a concise step by step approach. I shall refer to it when I start on the journey. I have the SL1210 project to bring to its conclusion. I've been looking for a reason to get a macbook. I can't use a macbook to share the iTunes library attached to the macmini via a wifi connection for playback ?

Peter Stockwell
31-07-2008, 09:38
Rob,

I'm stilling mulling the CD to lossless solution. I'm currently thinking along the lines of a squeezebox duet, and after a dac. But what bugs me about this is that I think I'll still need a CD player.

I've seen that Cambridge Audio makes the 640h music server, it's a 640C with a hardisk and wireless network capabilities, I bet it has a switched mode power supply, too. Functionally this looks like a neat solution, it can access files attached to my mac mini wirelessly, as well as reading it's own saved files. Granted 160Gb isn't huge. But it's a nice solution for the box count.

I'm currently using CDX/XPS, I haven't heard better than this at a price I'm ready to pay. My sense from readng reviews of cambridge kit, is that they're fine budget players but do lag behind players serval times more expensive. However Audiocom can upgrade the 640C so they may be able to upgrade the 640h. The 640h is £500 from Richersounds, a lot more expensive here in France.

cheers

StanleyB
31-07-2008, 12:26
The problem with many of these so called upgrades is that they just change the components for different ones. Few do anything more like change the actual circuitry for a better one.

Using an external DAC in the audio chain can be a good idea, but picking the right DAC is another story. Except for my own DAC, the TC-7510, I have not been able to find anyone else who makes a DAC that has been optimized for wireless streamed or PC based audio files other than CD audio and DVD audio. So consider your options carefully before parting with any money. Once you select a route to go it can cost a lot of money to change it.

Peter Stockwell
31-07-2008, 13:03
I just looked at the pricing of the TC-7510 dac, That plus an airport express and I can start playing around with the files already on my computer.

Certainly worth thinking about.

Thanks

snapper
31-07-2008, 13:20
I can certainly recommend Stans DAC.

I have a Perpetual Technologies P-1A & P-3A which have not been plugged into the system since a couple of weeks after I got the TC-7510.

Could be the BIGGEST bargain in hi-fi,along with the Denon DL 160 which I've just installed.

:gig:



For the price of a meal for two,with a bottle of wine,you can't go wrong.

tfarney
04-08-2008, 13:29
The problem with many of these so called upgrades is that they just change the components for different ones. Few do anything more like change the actual circuitry for a better one.

Using an external DAC in the audio chain can be a good idea, but picking the right DAC is another story. Except for my own DAC, the TC-7510, I have not been able to find anyone else who makes a DAC that has been optimized for wireless streamed or PC based audio files other than CD audio and DVD audio. So consider your options carefully before parting with any money. Once you select a route to go it can cost a lot of money to change it.

Stan - What exactly do you mean by "optimized for wireless or PC based audio files?" In layman's terms, if that's possible. IE: What are the audible benefits?

Tim

Peter Stockwell
04-08-2008, 16:58
plus an airport express and I can start playing around with the files already on my computer.



Just located a 2nd hand airport express; any used Dac ideas ?

Stan's, of course, is so affordable as to make that an almost redundant question.

StanleyB
04-08-2008, 17:15
Just located a 2nd hand airport express; any used Dac ideas ?

Stan's, of course, is so affordable as to make that an almost redundant question.
Email me and I can surely sort you out with a good deal;).

Peter Stockwell
04-08-2008, 19:47
Email me and I can surely sort you out with a good deal;).

Pigeon en route ;)

cheers

Peter Stockwell
11-08-2008, 00:36
I've been using the TC-7510 and the Beresford toslink cable and have been really pleased with the results for a total outlay of about 200€. Has got me thinking about what I might be able to use as a CD transport ...

StanleyB
11-08-2008, 09:32
Stan - What exactly do you mean by "optimized for wireless or PC based audio files?" In layman's terms, if that's possible. IE: What are the audible benefits?

Tim
Sorry Tim, only just caught sight of your question.
The answer is that I decided to use two chips that can be programmed for use in different types of applications, and not just the general CD or DVD audio D-to-A conversion process that other/most DACs are designed for.

My main electronics qualifications are in wireless transmission, which includes digital like wireless networking. I spent several years designing wireless stuff and was the first person to be granted UK approval for a wireless headphone and wireless video sender. I worked for a company called Philex at the time, so they made the money:(.

I also designed the 3rd MP3 player ever to hit the world market (MPress3), and the first one to figure out how to record and convert audio data on the fly for storage on a memory card. So I had enough knowledge about music compression and data losses in the PC/memory card music side of things, plus data and clock sync losses on the wireless side.

So when I came to develop the forerunner to the TC-7510, which was known as the TC-7500, I decided to use my knowledge of PC and wireless to take care of the errors that those types of of signal transmissions can suffer from. TOSLINK and Coax do not have handshaking error correction, and neither does wireless audio. But the chips I use have a couple of (obscure?) programmable features that can be used to correct or reduce certain types of errors in the incoming data stream. That includes correction of the audio data and the clock signal.

I have programmed my chip set to accurately handle the PC and wireless data according to the information I have from my previous work with those types of mediums, which is why SB3, Airport Express, and PC users can notice an immediate difference in the playback signal when they use my DAC.

Obviously I won't mention what control bits I programmed to function in my chip sets since that is my unique selling point, but all the information on what is possible with the chips are available from the chip manufacturers technical support department, and also in their datasheets. The trick is figuring out which programmable feature I utilized, and which ones I didn't need:eyebrows:.

As for the audible differences:
1. PC and wireless audio sounds almost the same, or not worse, than CD according to most people. That's assuming the audio data was ripped at a high enough quality and bit rate in the first place.
2. I don't need an anti-aliasing filter in my design. Those filters have a sharp cut-off frequency above 20KHz, which produces a phase shift at worse, and takes away overtones and subtle decaying effects. Most noticeable in certain type of instruments like acoustic guitar etc.
3. I don't need an expensive external clock. The receiver IC I use can be programmed to produce a low jitter clock. The manufacturer mentions that it is jitter free, but that's another matter..
4. I use surface mount components in the digital section of my design. Surface mount components don't have inductive leads and can therefore be used at far higher frequencies without affecting the leading and trailing edges of a square wave. The digital audio data are square waves, and any errors in the leading and trailing edges of a signal can quickly lead to decoding errors.
5. I don't use 44.1KHz as my DtoA conversion frequency. I use 352.8KHz for audio CD and 384KHz for DVD-A. This makes the DAC sounds less digital and more analogue.

It is a lot to read, but I hope it is clear:scratch:.

tfarney
27-08-2008, 12:33
It is a lot to read, but I hope it is clear.
Reply With Quote

Well, the parts that I understand are clear :)!

I'm pretty happy with the sound of my system, even with all of its compromises, but I know it begs for a bit of upgrading. The compromises of my old integrated amp are ones that I like. It is very smooth and tube like, with the right color in the right places. It can get better, I'm sure, but it's not a priority. And like I said in another thread, the Trends UD-10 I use as a DAC sounds good. I don't hear anything wrong -- no glare, no edginess, no overt problems. Still, I know if I'm going to upgrade, the DAC is the most likely suspect. What I don't know is what I'll get from that, if my amp is resolving enough to reveal the improvements, if a carefully considered step up will deliver enough of an improvement over the UD-10 to make it worth the investment.

We don't live in a world where we can walk into a shop and compare a bunch of DACs, unfortunately, so a lot of forethought and research is required. And possibly a bit of trial and error. But I am someone who believes that "you get what you pay for" is a comforting refuse of those who paid too much, and that the point of diminishing returns in audio can be very close to the ground, especially in digital technology, especially in a world market.

So your DAC is high on my consideration set along with a few others that seem to be deliberately attempting to build something that performs way above its price range. The Aeolis MagiDac, for example, intrigues me, but it hasn't been out long and there is little feedback out there. Your DAC, by contrast, has a ton of feedback on the net - some bad, some good, though I suspect, judging by the nature of it, that the bad is a bunch of nonsense unrelated to the actual performance of the product.

Thanks for your detailed response. I'd love to hear your product someday.

Tim

snapper
27-08-2008, 15:14
that the bad is a bunch of nonsense unrelated to the actual performance of the product.


Tim


I think you're probably spot on there,Tim.