306 replies to this topic

[georgehifi]

Hi all, I've now listened to the much praised Berkely Audio Alpha Dac mkII and the Ayre 7 and other hi end cdp or dacs that use the "latest" and "greatest" Delta Sigma type dac chips. And while they do sound very smooth and relaxing they seem to seriously lack dynamic impact throughout the audio spectrum, especially in the bass, which gives the lack of rhythm feel to the music. So much so the owner of the Ayre 7 has a later cloned version of a DBX unit between the cdp and pre so he can get the dynamics back.
These delta sigma dac chips measure great and have speced figures of 130+ db of dynamic range over the old much more expensive to produce multibit chips. But my preference sound and enjoyment wise are for the older multibit ones like Philips TDA5141 the Burr Brown PCM56 PCM61 PCM 63 PCM1702 and the PCM1704 because they give real impact to the music, which gives me back the rhythm and enjoyment, sure if they were implemented wrong they can be a little harsh but when done right the are just as sweet but so much more dynamic than the Delta Sigma ones.

Here is a good discussion one the subject and there are others to be found like on diy audio and other forums.

http://www.computera...elta-Sigma-DACs


Cheers George

Edited by georgehifi, 22 March 2012 - 11:25 AM.

[bhobba]

Hi George

You are far from the only one to hold that view. Welcome to the club. Although I have to say when fed correctly my WFS Saber based DAC gave a pretty good account of itself.

Thanks
Bill

Edited by bhobba, 22 March 2012 - 11:33 AM.

[wis97non]

It depends on the implementation.

Delta Sigma done well can have huge bass. The WM874x series for example often is reported to be bass heavy.

The Lamp Dac also is said to have huge bass even if a bit tubey (ie not as tight as some others). Check out www.parttimeaudiophile.com feedback.

[georgehifi]

It depends on the implementation.

Delta Sigma done well can have huge bass. The WM874x series for example often is reported to be bass heavy.

Yes but not dry tight and punchy like good multibit can, which give great rhythm.
Cheers George

[pete_mac]

I've been fortunate to do some back-to-back listening tests with a bunch of DACs lately, including my DAC19DSP with the PCM1704UK chips. There's something inherently 'right' about the sound - some of the others have offered better fine-detail retrieval (Sabre chipsets) but they haven't quite matched the 1704 for timbral and tonal performance and overall 'body'. I'm definitely a convert!

[georgehifi]

I've been fortunate to do some back-to-back listening tests with a bunch of DACs lately, including my DAC19DSP with the PCM1704UK chips. There's something inherently 'right' about the sound - some of the others have offered better fine-detail retrieval (Sabre chipsets) but they haven't quite matched the 1704 for timbral and tonal performance and overall 'body'. I'm definitely a convert!

Yes my favouirte has been the PCM1702k (which is close to the PCM1704k) with PMD100 as the filter, this combo with a dc coupled discrete solid state I/V and dc coupled discrete buffer and dc servo has been my reference for a very long time, nothing comes near it for dynamics, rhythm and tonal quality, except for other multibit dac's or cdp's. It just makes music happen and gives you that jump factor, you instantly tap your feet when the music calls for it.

Cheers George

[Arg]

The differences in sound between DACs is going to be down to the analogue stage implementation, or suboptimal design, implementation or minor faults.

[datafone]

I have found the lack of dynamics to be a result of upsampling.

Just my opinion

[georgehifi]

I have found the lack of dynamics to be a result of upsampling.

Just my opinion

This is true also, as I have found with the above favourite cdp of mine that has the PCM1702K's with the PMD100's I am able to plug in a laptop into the rear and with a software program from the now defunct manufacturer I am able to change 8 different stages of dither and 4 different stages of upsampling, amongst a host of other feature that can be changed all on the fly whilst listening to music.
I have found the more the upsampling the sweeter but less crystalline the tops become, and also the softer (still big) the dynamics become, like they have lost their leading edge snap and tightness in the low and upper bass, and the midrange looses it's blat from brass and percussion and presence and body with vocals.

Cheers George

[kajak12]

The differences in sound between DACs is going to be down to the analogue stage implementation, or suboptimal design, implementation or minor faults.

power supply and output stage all caps and resistors including regulators etc................

[kramered]

My AMR CD player with TDA1541A chipset and valve output stage in 'Bit-Perfect' (no upsampling) filterless mode is an amazing performer. George's comments of snap, attack and pace are spot-on. There's also a totally effortless dynamic range that can really let fly on appropriate material. Instrument timbre/overall tonality is also very true to the real instruments/voices.
I've also heard very good Sabre DAC players but I've found them a tad analytical.
Cheers,
EK

Edited by kramered, 24 March 2012 - 12:31 PM.

[a.dent]

Since taking delivery of my Audio-GD Ref 5 with it's PCM1704U-K chips I have retired my MInimax Plus DAC to the bedroom system.

The Minimax is very resolving but the sheen at the top end can become grating during an extended listening session.

The Audio-GD is a lot more relaxing and I am so glad I took the risk without hearing it. That word timbre comes to mind. It just sounds RIGHT.

Just because the Sabre chips are newer and have better specs doesn't necessarily mean the resultant DAC is going to be better.

[bhobba]

The differences in sound between DACs is going to be down to the analogue stage implementation, or suboptimal design, implementation or minor faults.

Don't agree with that at all - the Playback Designs, PDX, and Metrum, sound totally different yet are all very well engineered designs using entirely different converter technologies - and IMHO the differences are not entirely due to different output stages.

Thanks
Bill

[Decky]

I would like to stress this again - considering that we have been here at least half a dozen times - in the discussion this DAC chip over other DAC chip, that is.

How do you compare "sound" of one DAC chip to another and how can one draw conclusions about sonic qualities of a DAC chip alone when every time one listens to a DAC device there are several components that are responsible for "sound creation" - namely
- PSU (analogue and digital)
- DAC chip surrounding circuit and the DAC chip
- analogue output stage

So, if one has 2 DAC units (desktop devices as opposed to chips) there are the following possibilities if DAC 1 sounds better than DAC2

- PSU 1 is better than PSU 2
- Output stage 1 is better than output stage 2
- PSU 1 is better than PSU 2
- DAC1 implementation is better than the one in DAC 2

And there are also a million and one combinations of the above dot points - along the lines: PSU 1 is a bit better but OS2 is superior to OS1 but the real impact is implementation of DAC1 over DAC2.

If you get my point - can you even start to realise how a sentence

"TDA 1541 sounds more fluid than PCM1704"

does not make absolutely any sense and carries no meaning whatsoever.

Edited by Decky, 24 March 2012 - 08:40 AM.

[pete_mac]

Fair point Decky.

The closest I have come to being able to take power supplies and DAC circuit design out of the equation is the DAC19DSP vs the NFB2.1. Very
similar DACs apart from the chips themselves. The DAC19 is more convincing to my ears.

Edited by pete_mac, 24 March 2012 - 10:58 AM.

[Decky]

Yes I agree - those two DACs are very rare example - they come from the same factory and same designer - PSUs and OSs are practically identical - PCB design is similar - signal path is similar - the only thing different is digital processing side.


If you can do a simple A-B comparison - you might have some idea about the qualities of different DAC chips. Even in that case one has to exclude his own subjectivity.

[georgehifi]

There are too many audiophiles and techs that have now gone back to properly trimmed and implemented Multibit (R2R ladder network) type dac chips that have been disillusioned with today's Delta Sigma half multibit, half Bitstream (single bit), these are far easier to product compared to good Multibit chips (R2R). I believe here lays the answer, were are being bombarded with the specs of the Delta Sigmas and they are not relevant to the music we hear.
Here is a quote from one very knowledgeable tech on DIY Forum where all the guru's hang like Nelson Pass, Thorsten Loscech, John Curl and many many others like the banned nasty Jocko Homo, and they put many of the techs here to shame, they all use and advocate the use of older multibit dacs implemented properly and with good filters like the HDCD PMD100 or PMD200 but not DSD software copies.




"Quote:
Originally Posted by georgehifi
I have found I don't like todays super dacs (deta sigma) or whatever, they are smooth but lack life, jump factor, or whatever you want to call it. They claim better dynamic range on paper but to my ear cannot deliver it.
I have to agree with you George I think its because the dynamic range measurement is a relatively long-term average and our ears are sensitive to much shorter time scales. So we pick up the noise modulation inherent in the heavy degrees of re-quantization necessarily involved."


Here is another one to contemplate, Kramered's Abbington Music Research AMR CD-77 is their most expensive revered Reference Class cdp and uses, yes you guessed it an older type Multibit TDA1541 dac, their lower price lower graded later AMR CD-777 uses yes you guessed it again, a Delta Sigma chip, all this must ring bells, these multibit chips are getting very hard to buy new for these manufacturers, so why use them??????

Just remembered I think Thorsten Loscech was comisioned by AMR to be the designer of the AMR Reference CD-77

Cheers George

Edited by georgehifi, 24 March 2012 - 11:15 AM.

[GFuNK]

George, have your opinions been formed from ABX testing, casual listening or both? Not interested in a debate on the merit of either.

[georgehifi]

My opinions have been formed from long term A/B ing with many units. I used to be the Tent Labs cdp mods agent in here in Australia also the LC Audio Zapfilter modder and have seen/listened to heaps of different units through a very high rez system before Lightspeed Attenuator took over my time and effort. These are conclusion I have gather over many many cdp and dacs that I have had the pleasure to listen to, both mega bucks and high end budget, 80's 90' & now. And are backed up by statments of some pretty heavy hitters from O/S, not buy excited new owners of equiptment, that seem to rave about anything new they get.

Just look at the above AMR reference CDP, why do it when they have to scrounge the world for new TDA1541 ( 20 year old dac chips).
And look at the 2007 vintage Naim CD555 touted to be the best Lin or Naim cdp ever $30k's worth it uses the 90's multibit Burr Brown PCM1704 and 90's PMD200 filter chip

Chers George

Edited by georgehifi, 24 March 2012 - 12:14 PM.

[Arg]

The differences in sound between DACs is going to be down to the analogue stage implementation, or suboptimal design, implementation or minor faults.

Don't agree with that at all - the Playback Designs, PDX, and Metrum, sound totally different yet are all very well engineered designs using entirely different converter technologies - and IMHO the differences are not entirely due to different output stages.

I agree. They are due to the things I mentioned.

I would like to stress this again - considering that we have been here at least half a dozen times - in the discussion this DAC chip over other DAC chip, that is.

How do you compare "sound" of one DAC chip to another and how can one draw conclusions about sonic qualities of a DAC chip alone when every time one listens to a DAC device there are several components that are responsible for "sound creation" - namely
- PSU (analogue and digital)
- DAC chip surrounding circuit and the DAC chip
- analogue output stage

So, if one has 2 DAC units (desktop devices as opposed to chips) there are the following possibilities if DAC 1 sounds better than DAC2

- PSU 1 is better than PSU 2
- Output stage 1 is better than output stage 2
- PSU 1 is better than PSU 2
- DAC1 implementation is better than the one in DAC 2

And there are also a million and one combinations of the above dot points - along the lines: PSU 1 is a bit better but OS2 is superior to OS1 but the real impact is implementation of DAC1 over DAC2.

If you get my point - can you even start to realise how a sentence

"TDA 1541 sounds more fluid than PCM1704"

does not make absolutely any sense and carries no meaning whatsoever.

100% agree!

[GFuNK]

I would like to stress this again - considering that we have been here at least half a dozen times - in the discussion this DAC chip over other DAC chip, that is.

How do you compare "sound" of one DAC chip to another and how can one draw conclusions about sonic qualities of a DAC chip alone when every time one listens to a DAC device there are several components that are responsible for "sound creation" - namely
- PSU (analogue and digital)
- DAC chip surrounding circuit and the DAC chip
- analogue output stage

So, if one has 2 DAC units (desktop devices as opposed to chips) there are the following possibilities if DAC 1 sounds better than DAC2

- PSU 1 is better than PSU 2
- Output stage 1 is better than output stage 2
- PSU 1 is better than PSU 2
- DAC1 implementation is better than the one in DAC 2

And there are also a million and one combinations of the above dot points - along the lines: PSU 1 is a bit better but OS2 is superior to OS1 but the real impact is implementation of DAC1 over DAC2.

If you get my point - can you even start to realise how a sentence

"TDA 1541 sounds more fluid than PCM1704"

does not make absolutely any sense and carries no meaning whatsoever.

I completely agree... George, unless you can find 2 dacs with identical implementation aside from the dac chip, you are not comparing apples...

[kajak12]

I completely agree... George, unless you can find 2 dacs with identical implementation aside from the dac chip, you are not comparing apples...

Mr gfunk i own a tda1541 bases dac and i can change the dac chip with in 2 minutes eg:tda1541a,tda1541s1 and tda1541s2 they all sound different in the same dac so i am comparing apples with apples.........

[Nada]

unless you can find 2 dacs with identical implementation aside from the dac chip, you are not comparing apples..

A statement like this quote is often repeated in this context. Its a superficial argument. It does not appreciate the pattern recognition ability of the human brain.
By listening to many different CD player and DAC's as Gerorge has been priviledged to do, its possible to recognise the characteristic mark of a particular DA chip by understanding the similarities in sound signature of that DA chip in different machines.
The characteristics of R2R versus deltasigma are often recognised. George's experience is not isolated in an appreciation of R2R DA architecture.
Its also possible to perceive the family resemblance of chips eg PCM63 and PCM1704 and also to note their individual attributes.
Since every chip design is discrete and individual this is hardly surprising.
Its a similar story to tubes. Different brands, years and subtypes of tube's have a recognised signature. Thats much harder to rationalise then DA chips as the type of tube should use an identical topolgy while performing within set limits to meet that tube number designation. Yet the signature of tube subtupes is widely repeatable in different amps with different topolgies and parts.
Why wouldnt it be even more individual and recognisable for types of DA chips that have very different designs?

[Arg]

It does not appreciate the pattern recognition ability of the human brain.
....

Within the confines of the limits of human perception.

Why wouldnt it be even more individual and recognisable for types of DA chips that have very different designs?

See above

[datafone]

My view is that the chip matters, as does the power supply, output stage, and various other design elements.

To say DAC chips all sound near the same, is like saying all amps sound near the same

[empirical]

There are a lot of elements that make one DAC sound different from the next, however there are two elements in particular that cause first-order effects IME: (Most others are second order, and I will list these later)

1) Master Clock jitter and jitter rejection of the DAC
2) Digital filtering or lack thereof

You will notice that I did not even mention the D/A chip used. These actually dont vary hugely, except for the AKM series that sound a bit electronic no matter what you do in the DAC IME.

You will find that once you have a really low jitter source to feed the DAC, that most of them will sound virtually identical, particularly if you are using a preamp in your system, which masks a lot of detail and causes compression, even the best of them. I can point you to three TAS reviews where Steven Stone drove various different DACs (ranging from $1k-$7K) with the same low-jitter source and they were not only improved, they were virtually indistinguishable from each other, and Steven uses a near-field system too.

Digital Filtering is what generally sets-apart older ladder D/A chips and the like from newer Delta-Sigmas. Generally, in newer chips, the digital filtering is automatically selected and nearly impossible to override. There are a few exceptions. On the other hand, it is just missing in older chips like the PCM1702 and TDA1543. As a result, if you dont add a digital filter, these older chips sound more like analog. The downside is that they dont achieve the detail rendering that the newer chips do.

It would seem like the goal is to eliminate or reduce the effects of digital filtering using a modern D/A chip, and this is exactly what my goal was.

Okay, now lets talk about second-order differences in DACs in general. Here is a list of things that set them apart:

1) power subsystem - this has a major effect on the dynamics and bass tightness. Too few power decoupling caps, the wrong caps or wrong sizes of caps in the wrong places all has an effect. Voltage regulator speed and regulation accuracy has a huge effect also. Both of these are critical to achieving slam as well as control.
2) analog output stage - this can compress if there are too many stages or too many op-amps, as well as adding distortion and noise.
3) I/V converter - most D/A chips need this and the more perfect this is, the better the SQ
4) PC board effects - this is something that I discovered by modding for about 10 years. It was obvious when I modded a Mark Levinson #38/380 preamp. This preamp had long analog signal traces running from the front panel all the way to the back, more than a foot long. This preamp had a very dark sound due to this. Rewiring all of these traces by cutting them and replacing with pure silver wire in teflon tubing made a huge difference.
5) volume control - next to jitter, this is the next MOST IMORTANT THING to address in your audio system. Using digital volume control is not a good idea because more than about 9 dB reduction in volume starts reducing resolution. Using an active preamp (which is usually what is inside a DAC) is not good either because of the added noise, distortion and compression. This can and usually does suck the life out of the music. Passive linestages based on resistors are a bad idea also. The only ones that sor to work locate the resistors on the back of the amps, eliminating the capacitance of the cables in the response equation. Resistor passives generally reduce dynamics by limiting the current that reaches the amps. So what is the solution:

There are two actually:
a) Transformer-based linestage - if the transformers are well-designed, this is the most transparent of the choices. The drive from the DAC must be sufficient however. A benchmark DAC1 with op-amp output will not cut-it.
D/A control by changing the reference voltage - this does not add any parts to the signal path. No distortion, compression or noise is added, and no resolution is lost. In fact, as you reduce volume, the distortion decreases. This is the opposite response of any other volume technology. There is only one DAC on the market to my knowledge that has this.

Steve N.

[bhobba]

You will find that once you have a really low jitter source to feed the DAC, that most of them will sound virtually identical, particularly if you are using a preamp in your system, which masks a lot of detail and causes compression, even the best of them. I can point you to three TAS reviews where Steven Stone drove various different DACs (ranging from $1k-$7K) with the same low-jitter source and they were not only improved, they were virtually indistinguishable from each other, and Steven uses a near-field system too.

To a large extent that has been my experience - but an interesting exception was the Audio GD NFB 2.1 which was improved only a little. I would not say virtually identical though - a lot closer - but virtually identical - not to my ears. I could still easily hear the difference between my WFS, Metrum, PDX and other DAC's I tried - but it was certainly a lot closer - especially with the WFS which was improved out of sight. I also always direct connect which, again in my experience, just as Steve says, allows more detail through. My preference so far is for the PCM1704 and the proprietary DAC they use in the Playback Designs with whatever they use in the Metrum slightly behind those two. The Phillips Double Crowm IMHO is in a slightly different category - divine on Dainna Krall etc but can get a bit muddled on heavy rock and orchestra etc.

Thanks
Bill

[bhobba]

My view is that the chip matters, as does the power supply, output stage, and various other design elements. To say DAC chips all sound near the same, is like saying all amps sound near the same

I don't think they sound near the same either - but the gap closes by an amount that leaves you scratching your head when you feed them from a genuine low jitter source.

Thanks
Bill

[empirical]

I don't think they sound near the same either - but the gap closes by an amount that leaves you scratching your head when you feed them from a genuine low jitter source.

Thanks
Bill

What is really striking I think is the difference the low jitter source makes with older chips like the stacked TDA1543. Driven with a CD transport, it sounds inferior to most modern D/A chips, but with a low jitter computer source, it usually pulls ahead.

I am not saying that all D/A chips sound identical. This was just the case in those TAS reviews. I agree with Bill that the differences narrow with a low-jitter source.

This drives home the point that I make over and over, that it does not make sense to buy a $100 USB converter to drive your $3K DAC. Makes more sense to buy a $1500 converter and a $1500 DAC. Think of the digital source as the analogy to your phono cartridge in the digital domain. Who would buy a $200 cartridge for a $3K turntable.

Steve N.

[jkeny]

Completely agree with you, Steve & another aspect that is often overlooked is that a DAC which has an ASRC (Asynchronous Reclocking) stage tends to mask the sonic advantages of low jitter source. This can be somewhat confusing as Upsampling is marketed as a jitter reducer but that's a whole other discussion.

[bhobba]

Completely agree with you, Steve & another aspect that is often overlooked is that a DAC which has an ASRC (Asynchronous Reclocking) stage tends to mask the sonic advantages of low jitter source. This can be somewhat confusing as Upsampling is marketed as a jitter reducer but that's a whole other discussion.

OMG is async maddening or what. It certainly closes the gap but does not eliminate it - not by a long shot - which leads to all sorts of discussions with those who do not actually listen to stuff and because they can't think of a reason say it cant be like that - but it is - it is.

Thanks
Bill

[empirical]

OMG is async maddening or what. It certainly closes the gap but does not eliminate it - not by a long shot - which leads to all sorts of discussions with those who do not actually listen to stuff and because they can't think of a reason say it cant be like that - but it is - it is.

Thanks
Bill

Bill - I think Jkeny was referring to asynchronous resampling in the DAC, rather than async USB protocol. Is that what you are talking about?

I agree with JKeny completely. After experiencing 3 or 4 different resampling chips in various DACs that I modded over the last 10 years, I have come to the conclusion that noone is doing a good job of this in silicon. Probably the best of these is the TI/BB SRC4192, but still nowhere near as transparent as an async USB interface with no resampling when using the same clocks for both.

Steve N.

[jkeny]

Bill - I think Jkeny was referring to asynchronous resampling in the DAC, rather than async USB protocol. Is that what you are talking about?

I agree with JKeny completely. After experiencing 3 or 4 different resampling chips in various DACs that I modded over the last 10 years, I have come to the conclusion that noone is doing a good job of this in silicon. Probably the best of these is the TI/BB SRC4192, but still nowhere near as transparent as an async USB interface with no resampling when using the same clocks for both.

Steve N.

Yes Bill - I was referring to ASRC (asynchronous reclocking or resampling) as I stated in my post. The Asynchronous terminology is often confusing & confused on both forums & in marketing!
The most controversial of the ASRC approaches is in the Sabre DACs & it might even be the best implementation as it uses a different approach than the standard ASRCs. But despite what the overenthusiastic marketing department of ESS state this is not a "jitter elimination" technology in practise.

Edited by jkeny, 25 March 2012 - 10:13 AM.

[bhobba]

Bill - I think Jkeny was referring to asynchronous resampling in the DAC, rather than async USB protocol. Is that what you are talking about?

Hi Stove

In this case I was talking about asynchronous resampling in the DAC - I have found DAC's that use it are less sensitive to devices like your Off-Ramp - but sensitive they still are - maddeningly. And one of the DAC's I heard with the biggest difference when using the Off-Ramp was the SABRE - my hypothesis being it is not as jitter immune as its made out - not by a long shot.

Thanks
Bill

Edited by bhobba, 25 March 2012 - 10:42 AM.

[jkeny]

Hi Stowe

In this case I was talking about asynchronous resampling in the DAC - I have found DAC's that use it are less sensitive to devices like your Off-Ramp - but sensitive they still are - maddeningly.

Thanks
Bill

Bill, the point I was making was that these ASRC approaches when used with high jitter sources seem to improve the the sound by reducing jitter to the extent that Toslink, SPDIF, AES feeds can all sound very similar. The best ASRCs can do a reasonably good job. The problem arises when a source below a certain level of jitter (don't know what level this kicks in?) is fed to this DAC - it too doesn't sound much better than Toslink, etc. Now this could be interpreted as the ASRC doing a good job & reducing the jitter level at the input of the DAC chip to an inaudibly low level. But my experience ( & I think Steve's also) is that ASRC, while reducing jitter to a lowish level (let's say 50pS), also adds noise to the signal. When fed with a digital signal of lower than 50pS (let's say), it doesn't improve this any further, in fact it adds a noise which masks the audible potential of this low jitter source. Hence all sources begin to sound alike.

This would explain why Steve's & my low jitter sources do not show as big a difference compared to other sources when used with these type of DACs. For instance, have a look at the Stereophile review of the Off-Ramp & his comments on the sound with the upsampling dCs Debussy DAC "Well, as definite as had been the differences between the Halide and Off-Ramp with the Transporter, and between the wall-wart– and battery-powered Off-Ramp, the sound was consistently excellent with the Debussy. While the Off-Ramp perhaps still had a slight advantage in soundstage size and focus, it was not a difference I could confidently detect with every recording."

There are certain DACs that allow this reclocking or resampling (usually called upsampling) to be turned off & this effect can the be directly confirmed & heard!

Edit: Ah, yes, I see you edited your post. The Sabre DAC is an interesting one indeed - it doesn't use a PLL (which is the problem area) but it is certainly not jitter immune & does show differences between sources. The dCs is another interesting one in that it has a very low cut off frequency PLL (1 Hz) which takes about 8 secs to lock to the SPDIF signal but is said to perform very well.

Edited by jkeny, 25 March 2012 - 11:03 AM.

[Nada]

D/A control by changing the reference voltage - this does not add any parts to the signal path. No distortion, compression or noise is added, and no resolution is lost.

Thanks Steve for your fascinating and expert sharing on this forum.

Regading the extract above from your discussion of volume control which DAC's have used it?

I wonder if there are disadvantages like linearity suffering as the ideal reference voltage is departed from?

What kind of dB range can this volume control yield?

Thanks.

Edited by Nada, 25 March 2012 - 12:22 PM.

[jkeny]

Regading the extract above from your discussion of volume control which DAC's have used it?
.

Nada, I'll give you two guesses, nah, it's too obvious, one guess! (Hint look up his website )

[John H. Darko]

But despite what the overenthusiastic marketing department of ESS state this is not a "jitter elimination" technology in practise.

Ain't that the truth.

[empirical]

Hi Stove

In this case I was talking about asynchronous resampling in the DAC - I have found DAC's that use it are less sensitive to devices like your Off-Ramp - but sensitive they still are - maddeningly. And one of the DAC's I heard with the biggest difference when using the Off-Ramp was the SABRE - my hypothesis being it is not as jitter immune as its made out - not by a long shot.

Thanks
Bill

My experience as well. When posters say "just get a DAC that eliminates jitter and then you dont need to worry about the source", I just say "right", show me such a DAC. Never heard one, and I've modded plenty of DACs from other companies.

The test I give them is to try a CD Transport and then a Squeezebox or other computer source. If they sound different, then the reclocking is not eliminating the jitter. Most of the time, you can just try two different S/PDIF cables and hear a difference.

Steve N.

[jkeny]

My experience as well. When posters say "just get a DAC that eliminates jitter and then you dont need to worry about the source", I just say "right", show me such a DAC. Never heard one, and I've modded plenty of DACs from other companies.

The test I give them is to try a CD Transport and then a Squeezebox or other computer source. If they sound different, then the reclocking is not eliminating the jitter. Most of the time, you can just try two different S/PDIF cables and hear a difference.

Steve N.

Of course it might not be jitter that is causing the sonic differences between the different sources

[empirical]

Regarding the extract above from your discussion of volume control which DAC's have used it?

To my knowledge only my own Overdrive DAC.

I wonder if there are disadvantages like linearity suffering as the ideal reference voltage is departed from?

No disadvantage in my case. You cannot just take any off-the-shelf D/A chip and do this without experiencing linearity problems however. No, I will not tell you what chip I'm using.

What kind of dB range can this volume control yield?

50dB

[Nada]

Thanks Steve. Thats a brilliant volume control design. Congrats.

[John H. Darko]

This drives home the point that I make over and over, that it does not make sense to buy a $100 USB converter to drive your $3K DAC. Makes more sense to buy a $1500 converter and a $1500 DAC. Think of the digital source as the analogy to your phono cartridge in the digital domain. Who would buy a $200 cartridge for a $3K turntable.

Steve N.

Agreed. I get a regular flow of emails asking "which DAC for $1000?". I nearly always advise that an Audiophilleo/JKSPDIF/whatever should be factored into the budget. For example, an Audio-gd NFB-2.1 + JKSPDIF easily bests the solo Rega (via USB).

[RSG]

George, I believe this link pretty much sums up what you have stated...your experience mirrors mine.

http://www.mother-of.../conversion.htm

Edited by RSG, 26 March 2012 - 04:08 PM.

[georgehifi]

George, I believe this link pretty much sums up what you have stated...your experience mirrors mine.

http://www.mother-of.../conversion.htm

http://www.mother-of.../conversion.htm

Very much so RSG thanks for that, I wish I had found this link to post in my first post then it may have made the doubters think again before their beliefs that newer must be better.

This article will clearly show the opposite, to those who take the time to understand it. Although I don't agree to all that Altman preaches, he did get this right.

It's a bit like comparing digital/smp amps against good class A or a/b linear amps, and you may know my dislike of the former, it's well documented in these forums. And this takes the same direction, where the mighty dollar seems to steer where we go with development.

Cheers George

Edited by georgehifi, 26 March 2012 - 04:57 PM.