[Triode User]

What are customers saying/hearing is different about your cables then the others?

They don’t sound as harsh.

 

[Triode User]

So it is distortion that follows the signal, not noise... Are you sure about that? If so, it's easily detected in a null test. Can you tell me a DAC that is particularly subject to this kind of distortion so I can check it out? It probably would show up in the THD ratings, wouldn't it?

If you only answer one of my questions, please make it the one about the DAC that is particularly subject to RF.

A for instance, the last cable I sold was to a customer with a TAC DAC8. (I think I got that name right). I am not sure it is particularly susceptible to RF noise.

 

[bigshot]

I'd like to know a model where this problem has been identified and reported. If you don't know of any, that's OK.

 

[Steve999]

I remember measuring small improvements on my old ODAC when using the USB cable provided with a ferrite bead compared to some other random one. I believe JDS documented that at some point. but I can't say that I could hear a difference. also if a ferrite bead is the answer, why wouldn't the DAC manufacturer provide it or even better, have it inside the DAC? I agree with the possibility, but I'm talking about a small DAC that costs the price of some of the USB cables discussed in this topic. if I purchase an expensive DAC and the guy didn't implement some ferrite bead that could instantly improve the overall fidelity, it's probably time to go get a DAC from a better designer.


also in my limited experience, op amps and amplifiers in general tend to be the bigger issue with RFI and other unwanted signals(am I wrong about that idea?). I'd be slightly surprised to have significant issues in the DAC to the point where the total volume of a shielded cable would grab signals that make a noticeable difference compared to another random shielded cable, while at the same time having a problem free amplifier. I'm sure it happens, but it's certainly not what I'm used to.

I've got some kind of silver junky USB cable with a ferrite band I'm using right now (don't know what it came with) and Sony provides USB cables with ferrite bands once in a while based on my distant memory. I always wondered about them.

 

[GrussGott]

You've just dismissed all the objective data supporting theirs no audible difference between usb cables, but haven't provided any that supports your argument that there is.

Well sure, but in my defense that's only because that's not my argument.

Rather: "it's possible, I've heard a difference, many others have, thus observed phenomena deserves investigation until the mechanism is known and manipulable, or proven false." However, many do the unscientific thing and just jump to, "welp, no makes the most sense to me (because assumptions/speculation), so I'll just assume and advise that's scientific fact without the actual data proof it really is". And then for some weird reason (big ego, lack of humility, inferiority complex), they're so bold in their unproven opinion, they start asking others to disprove their unproven opinion! Bizarre right??

So my argument: if one is doling out advice, be able to prove it as fact or disclose you don't know for certain (and ideally advise the safe middle ground) I probably got that way because in all the sciency work I've done for my career, advice based on unproven assumptions kills people. (as far as I can tell, people in audio industry have a lower standard of knowledge for giving advice)

As they say in aviation: there are old pilots and there are bold pilots, but there are no old bold pilots.*

* Interesting Counterpoint: As they say in investment banking: boldness is genius.

So ... one can decide if science is more like aviation or investment banking.

 

[Triode User]

I'd like to know a model where this problem has been identified and reported. If you don't know of any, that's OK.

So far all customers irrespective of dac report a decrease in harshness. That implies widespread RF susceptibility but to be accurate I do not know of models where the problem has been identified and reported.

 

[gregorio]

My point is the RF noise overlay on top of the digital signal and how usb cables either by accident or design might change that RF noise and so give rise to the thought that usb cables can change the music we heat from a dac.

Yes but my point is, RF is not going to affect the digital signal itself and change the 0's or 1's. The only possibility is therefore RF leaking into the analogue section which indicates a poorly designed DAC, as even cheap DACs are able to isolate well enough to reduce interference to many times below audibility, so why apparently can't audiophile DACs? If you do have a faulty DAC, why wouldn't you want to fix/replace that DAC instead of buying a cable that costs more than a new non-faulty DAC? It's this logic I don't get, even if audiophile USB cables could fix some DAC leakage issue and I've not seen any evidence to suggest they can.

Furthermore, I've done a fair bit of testing in the past on S/PDiff (using BNC coax), although only once on a consumer DAC (actually it was an AVR), I've not measured any interference even near audibility and that was in a high RF environment.

G

 

[bigshot]

So far all customers irrespective of dac report a decrease in harshness. That implies widespread RF susceptibility but to be accurate I do not know of models where the problem has been identified and reported.

Audiophiles claim everything they buy makes a "night and day" difference. If we accepted anecdotal testimonials on manufacturer's website, then Brilliant Pebbles makes a huge impact on soundstage and clarity.

If it's audible, it's measurable. Measuring isn't hard. If it's real, someone will have measured it. If dealers have to depend on anecdotal testimonials, it probably isn't real. If it is just a new problem and no one has measured it yet, you can help me get access to a unit that is clearly susceptible to this problem and we can set up a controlled listening test and measurements of it, I'm sure the folks around here would be happy to pitch in and help you do that. But just saying "all DACs have this problem" isn't good enough, because a lot of us have DACs that are audibly transparent and clearly don't have high levels of RF noise.

I would like to get access to any DAC that isn't audibly transparent for any reason. I've been asking that for over a year, and no one yet has been able to help with that. That tells me something.

 

[Triode User]

a lot of us have DACs that are audibly transparent and clearly don't have high levels of RF noise

How do you know that?

 

[GrussGott]

what parameter do you think is missing where the cable would measure a audible difference?. ... Obviously the person you quoted has a agenda to sell us dacs

(1.) Assuming your parameter question is even the right question (and that'd be an assumption, not science), it doesn't matter what you or I "think is missing" because we're not digital signals processing scientists, thus any conclusion we'd come to would be likely wrong or at least incomplete.

(2.) I have no idea what his "agenda" is or isn't, and - again - you're making a large assumption there. You might want to remember that doctors, lawyers, accountants, pilots, and many other professions all have "agendas" to give you bad advice. For example, a doctor gets paid when you're sick, a lawyer get paid when you need one, same with an accountant, a pilot gets paid as long as he's sitting in the cockpit so what does he care about delays?

I guess I'm wondering how you get through life never using doctors, accountants, lawyers, or anyone else that gets paid to solve a problem for you. (the person who represents themselves has a fool for a client and all that)

Anyway, I judge advice on its merits, and his advice was well written and matches that of many others I've heard from - if you choose to ignore it, I'm not surprised - I trust your advice way less since you don't make DACs or cables or anything. (nor does it match what digital signals processing engineers have shown me)

 

[bigshot]

How do you know that?

Specs, measurements, controlled listening tests. I have an Oppo HA-1. It is audibly transparent by all three of those. I've never seen any measurement of a DAC that had audible levels of noise or distortion, have you?

 

[jagwap]

Specs, measurements, controlled listening tests. I have an Oppo HA-1. It is audibly transparent by all three of those. I've never seen any measurement of a DAC that had audible levels of noise or distortion, have you?

I have. I can say that only if I use your own description of what distortion covers: everything that is different to the original signal. If it is THD and IMD then no. It had audable levels of phase error. I also heard an amplifier that had audable levels of crosstalk. Neither of these are usually described as distortion, as they generally have specific decriptions in audio design. However you have used the definition of dustortion broadly here before, so I am assuming that is how you continue to use it.

 

[bigshot]

Has it been measured to have differences, or has there been a blind controlled test that verifies that it's audible? If so, what make and model? I'm looking to find out if a colored DAC actually exists. All I've found so far is reports that are anecdotal and sighted with no real controls.

Do you have access to this DAC so we can set up a test and measurements as a group?

 

[jagwap]

Has it been measured to have differences, or has there been a blind controlled test that verifies that it's audible? If so, what make and model? I'm looking to find out if a colored DAC actually exists. All I've found so far is reports that are anecdotal and sighted with no real controls.

Do you have access to this DAC so we can set up a test and measurements as a group?

It was fixed. I try not to released know issues.

 

[bigshot]

Ah. It was a defective one. That happens.