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16 minutes ago, ghost4man said:

I have had the opportunity to hear quite a few systems and I honestly cant speak highly enough of Redbook CDs. They do the 

job in spades and I am not convinced that this merry go round of 64/128/256/512 DSD necessarily brings about a better result

simply because the numbers go up.

 

Agree in principle with all you're suggesting through an often overlooked aspect of building a digital signal chain. Higher sample rates and greater bit depths make for more flexible digital filtering. Broadly agree with comments on PDM (DSD) vs PCM methods (that's highly DAC-dependent IMHO) though as for generally increasing sampling rates and bit depths... it just allows for easier filtering from a number of perspectives. Assuming you've the compute grunt to do it. Yes there are practical limits after which returns are negligible, it's similarly fair to suggest Redbook wasn't built for this much either.

 

Am a Redbook freak myself, have a system that is NOS Redbook and extremely ol-skool in intent. The other system is turning into an 8 way active and faces much the same challenges the OP has (save for my having not gone into DSD).

 

23 minutes ago, ghost4man said:

I think before you move forward you need to identify what the actual problem is in your system and then address that.

 

Best words yet this IMO :) would suggest there's an elephant in the room wearing a tee shirt labelled "DSD" that's complicating things presently :P 

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Ok ALL I made a mistake !

TB thanks for correcting me.

MH  As you can see from above somewhere along the way I though that ULT PRE and curryman had same dac

again my mistake. It was not my agenda to say anything bad about TB product if fact when I first saw TB dac on DIY forum

I sent an email about cost as I would have purchased back when he put first pic up on his post.

 

ALL WHO HAVE REPLIED TO MY COMMENTS

I am not trying  sell anything to KW

TB and MH have showed KW a product at if it was retrofitted with a Lan input He could compare it to NADAC.

I have ask what type of connection KW is using to his NADAC  and when I found that out I said why look  at TB'S DAC .

 

Peter

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3 hours ago, rmpfyf said:

 

Agree in principle with all you're suggesting through an often overlooked aspect of building a digital signal chain. Higher sample rates and greater bit depths make for more flexible digital filtering. Broadly agree with comments on PDM (DSD) vs PCM methods (that's highly DAC-dependent IMHO) though as for generally increasing sampling rates and bit depths... it just allows for easier filtering from a number of perspectives. Assuming you've the compute grunt to do it. Yes there are practical limits after which returns are negligible, it's similarly fair to suggest Redbook wasn't built for this much either.

 

Am a Redbook freak myself, have a system that is NOS Redbook and extremely ol-skool in intent. The other system is turning into an 8 way active and faces much the same challenges the OP has (save for my having not gone into DSD).

 

 

Best words yet this IMO :) would suggest there's an elephant in the room wearing a tee shirt labelled "DSD" that's complicating things presently :P 

And that is a good start.

IMHO, I think the fact that Keith spoke to Dave(TB) is evidence of him knowing that he has an issue and wanting to seek some sort

of resolution which is a positive start because so many of us dont.

 

In my own system I have elected to go active due to the fact that I have added a true ribbon to my 1Ds which were previously 2 way but with the ribbon would be 3 way.

 

Along the way I have had hurdle after hurdle which I needed to address so I have direct experience in terms of fault finding and then seeking a solution.

Power amplifiers had to be changed, power supply from the board had to be upgraded, tweeter driver had to be replaced etc.

So I have had to bite a very frustrating bullet to get to where I am.

 

And the DSP still requires resolving which I believe will occur.

 

Sufficed to say it is a process which can at times be quite challenging.

 

I remain unconvinced that the newer technologies will inherently give a better outcome.

 

More than happy to participate in double blind testing to set the record straight.

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7 minutes ago, ghost4man said:

I remain unconvinced that the newer technologies will inherently give a better outcome.

Best system I've ever heard was a fullrange, Redbook, CD transport, SET system. Best by some margin. It was not what some would call 'expensive' either. My Redbook rig is a, ahem, 'commoditized' version of that rig. Starting with the notion that I store my stuff on a network, and that at some point in the chain I need a volume control. The other rig is just different. (Cutting a long story short) I don't have to tune components to give passive filtering, I can tune filters at significantly less time and cost. I have have mode frequency range without expensive crossovers, and I can change them as I like. I can spend less time tuning the room and more convolving the source. ClassD amps are a good thing now, and there's enough bits in source and internal digital transport to throw a few away and have a digital volume control practically free of artefacts. A lot of this simply didn't exist at the dawn of Redbook. There's no doubt that the end result will sound different - quantitatively resolving, sure, though whether a 'better' or 'worse' outcome is wholly subjective. 

 

Bringing it home I think the OP is brave to share the journey with us. @Keith_W is trying very hard and with as much forethought as any customer has any reason to pull together. Beyond a certain level of fidelity - MiniDSP and DEQX serve lower and mid portions of what's possible with DSP extremely well - there's really not been a lot out there and so far it's all for customers to discover.

 

I think the DSD question is a fair one - I don't subscribe to DSD personally though it's a mainstream format now in our audiophile patch of the world, and it's reasonable to expect that a DSP solution exists... somewhere! I think the stark realisation is that a DSP capable of treating DSD and PCM in source formats throughout maybe doesn't exist yet, and if so, what's a next best way of doing it. I mean... B&O released the mother of all DSP'd speakers - Beolab 90, it really is an impressive bit of engineering - zero DSD support. The DSP operates up to 192kHz PCM only. And B&O's resources likely exceed the OP's. Not an easy task, then, even though things change fast.

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23 hours ago, Keith_W said:

All that I have learnt really makes me wonder whether DSD is really all that important in the scheme of things. Attempting to go full DSD was part of my "final 1%" philosophy. Since I already have most of the chain in place, I may as well keep going. But if I knew then what I know now, I would have settled for PCM. It's easier. 

What's the issue with just swapping out the NADAC for a multi-channel PCM DAC? Is it the source music? Yes, the computer might be over-specified but wouldn't the remainder of the chain be kept in place?

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There is no issue swapping the NADAC for a multi-channel PCM DAC. In fact, I already do it at the moment. The RME DAC is an 8 channel PCM DAC. 

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7 hours ago, Keith_W said:

In fact, I already do it at the moment. The RME DAC is an 8 channel PCM DAC. 

And what has your experience been so far with the RME...

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Besides the technical issue regarding the PC, do you have any "musical" issues with your setup?

It sounds to me that you have overcome most technically issues, or have found a solution yet to be implemented, but it also sounds your search is far from over at the same time.

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@Rob181 the RME in some ways is better suited to my system. The reason why is because of the gain structure of my speakers. It has a very high efficiency horn, which has been made even more high efficiency by removing the passive crossover from the signal path. This is paired with a low efficiency woofer, which has been made even more low efficiency by swapping the standard driver with a modified one. Therefore I need to cut down the signal to the horns and boost the signal to the woofers as much as possible. 

 

The RME is capable -30dB to +20dB gain. In contrast the NADAC is -12dB to 0dB from memory. I emailed Merging to tell them that the range of the individual channel trim is not enough when you are running an active system but I don't think they wanted to listen. 

 

As for the SQ, the NADAC does appear to sound more refined than the RME. It's a taste thing. But what is not a taste thing is the obvious computer noise that you can hear with the RME at times. I don't know why or where it comes from, but it's there. 

 

@Primare Knob I knew that someone would eventually ask me that question! Measurements are one thing, but sound quality is another. What has been driving me nuts for months is a smearing effect that I can hear in some frequencies but not in others. My ears tell me it's around 2000Hz so I don't think it has anything to do with the crossover, or distortion from the tweeter or horn (because the horn should be running well within their linear range, and the tweeter crosses in at 3500Hz). It doesn't show up in my frequency sweeps or waterfall graphs or any sweep that I can think of. I have complained about this to some friends including another Acourate user who reads this forum but doesn't post (hello Aris!). And some other SNA'ers who have visited have remarked on it either voluntarily or noticed it after I point it out. 

 

This smearing effect seems more pronounced on the NADAC than the RME. It is also worse with HQPlayer compared to JRiver. It makes no difference if I switch HQPlayer from DSD to PCM. 

 

The other issue is that computer noise is transmitted to the DAC's. The folks at Computer Audiophile forum were quite unhelpful - when I asked the question, half the respondents denied there was a problem and refused to consider that the PC would be the source of the noise. The other half suggested magic cables. When I reported that switching from an SMPS to an LPSU helped reduce the noise, half of them accused me of making things up. 

 

I therefore no longer visit Computer Audiophile. 

 

I don't think anybody on this forum will be able to solve my problem short of actually visiting the system and hearing it for themselves. I will eventually diagnose it and fix it. 

Edited by Keith_W

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22 minutes ago, Keith_W said:

But what is not a taste thing is the obvious computer noise

WOW...now that does surprise me...

Your treatment by the CA forum made me smile...

You would have been quite the heretic...

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Just as a train of thought.
You are using high efficiency horn speakers, which could potentially blow up minor imperfections, where the noise floor isn't low enough.

Could it be bad channel seperation on the Nadac? Have you tried swapping channels?

My first thought is that it might have to do with the interface. Do you use the AES output from PC into the RME?

The Ethernet connection for the Nadac should actually be as good as it gets, as it would be galvanized isolated from each other.

My second thought was, if it could be related to difference in the power consumption between programs on the PC. But if changing to PCM doesn't make a difference than perhaps not.

Maybe there is a difference between JRiver and HQ Player in which package it delivers the data. Funny thing is, dat my DAC seems to perform better when I deliver the 24 bit data in a 32 bit wrapper. But this should effect the whole performance and not an isolated incident.

If the troubled frequency is around 2000Hz maybe you could use this as a starting point for finding a technical reason for something that could be a possible cause.

Maybe have a chat with@davewantsmore as he seems to have a good grip on the PC - DAC interface.

I think he posted a few times that the only thing you need to keep your PC out of your DAC is a large buffer and independent power supply. (Something along those lines)

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11 hours ago, Primare Knob said:

I think he posted a few times that the only thing you need to keep your PC out of your DAC is a large buffer and independent power supply. (Something along those lines)

That is over simplifying it somewhat....  but the point is that it is hard to generalise.   It depends on how sensitive your DAC is to unwanted electrical signals (via the mains and digital connection), and to the quality of the digital signal itself.   DACs vary widely in this regard.

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Quote

obvious computer noise that you can hear with the RME at times

If this is an actual audible distortion, like a buzzing/click/pop, etc.... then it is almost -always- a driver/configuration issue.

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13 hours ago, Keith_W said:

The other issue is that computer noise is transmitted to the DAC's.

Is the noise audible when nothing is playing? .... or does it only happen with the sound?

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13 hours ago, Keith_W said:

Measurements are one thing, but sound quality is another.

There are only two possibilities here.   Either you do no know how to measure what you are hearing, or what you are 'hearing' doesn't exist.

 

If you can narrow in on a specific frequency band, then that will help a lot to then poke into some measurements to identify what is happening.   Anything that you can clearly hear, will be clearly present in measurement data - it will just need to be the right stimulus, viewed in the right way.

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Part of the problem I think is that the measurement loop is different to the listening loop. 

 

Measurement loop goes like this: Acourate -> RME -> System -> Microphone -> RME -> Acourate

 

Listening loop goes like this: HQPlayer -> NADAC -> System -> Ears

 

I have no way to run an ideal measurement loop, which would go like this: Acourate -> HQPlayer -> NADAC -> System -> Microphone -> RME -> Acourate

 

The reason it is not possible is because HQPlayer does not have a digital input. So it is possible that either HQPlayer or the NADAC is generating the spurious frequencies which I can hear (and yes I can hear pretty well, thank you very much). I have tried eliminating both variables by doing these permutations: 

 

- JRiver -> NADAC -> System -> Ears

- HQPlayer -> RME -> System -> Ears

- JRiver -> RME -> System -> Ears

 

Some permutations get rid of the problem frequency better than others. And before you ask, the frequency response neither shows a peak at the problem frequency nor a "finger" on the waterfall graph. 

 

And yes, there is a SQ difference between HQPlayer and JRiver. Neither of these players is ideal. 

Edited by Keith_W

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