Bruno has provided everyone with the means of analysing this. You just have to realise that there are indeed sections in the NC500 data sheet which relate to the design of the input buffer.
I think it is you who are stereotyping with the "templars of science" here. Your comments would be appropriate if the audiophile foo I was referring to was actually just a product of my own imagination, but unfortunately I have came across all that stuff for real, all to often, on numerous "audiophile" boards - many of which actually have explicit rules against questioning (or even clarifying) any claims, no matter how absurd.
You might not know one. I definitely do.
If you say so.
Let's not commit the standard silly mistake of confusing making music with reproducing recorded sound. Two entirely different things.
No, but if you make a claim that a cable alters the sound, and make that claim purely based on your own subjective, uncontrolled observations without any other evidence, then you have stepped outside the fields of science and engineering and into belief, superstition and faith (or perhaps marketing).
I certainly hope so. It is just circuit analysis.
The rest is, well, boring and tiresome; and, I suspect, it is of little use to Boggit. 540+ posts and little actual content. Again. Best to simply walk away from the repetitively boring off-topic red herrings.
The rest is, well, boring and tiresome; and, I suspect, it is of little use to Boggit. 540+ posts and little actual content. Again. Best to simply walk away from the repetitively boring off-topic red herrings.
Well, talk to that guy then instead of talking about him behind his back. To me you are still part of the "templars of science". I think the tribe name suits you well. That or "bullies of science". Take your pick.
For you it is a silly mistake, for me it is pretty important.
My signal path continues from speaker to my through the room, to my ear, and even to my brain. So i allow myself to have a personal opinion or things i have actually tried. The main function of my hifi set is to make me a happier or more relaxed person. I have noticed that that cannot be achieved in my case, purely based on science we currently know. I don't care so much anymore about the "the real" as objective truth, but how things affect my perception (the subjective side), being it red color, or different R,L or C values on the cable.
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Come on guys. Enough already. If I were Boggit I would ask for all the posts in this latest able to be removed. (Including my own in 529.)
Interesting topic going on here. Seems like we have hit a dead end for the hard core objectivists. I am reaching out for solutions to my questions but can't seem to get any solid ones:
DACS Have they gone about as far as they can go? | Audio Science Review Forum
Why don't we just stay on topic and discuss Boggit's NC500 build? Boggit, do feel free to ask the moderators to clean up your thread.
Buffers
I wonder how this will eventually be sorted out as far as I understand we have one person saying 47k resistors are causing noise and another saying that they are not so what is the answer.
I wonder how this will eventually be sorted out as far as I understand we have one person saying 47k resistors are causing noise and another saying that they are not so what is the answer.
What do you think the answer is?
The physics of what I posted is very straightforward. However, a couple of points to remember... Boggit has not disclosed his circuit (or BoM). His circuit may be different from the one I posted/analysed. I have not had access to the physical one. I believe the Sparkos folk analysed the Hypex circuit. Again, perhaps this is different. What I did is look at the "recommended" buffer design and add in the components I would expect to see in such a circuit dealing with EMF rejection, DC blocking etc - the bit in the box on the left (of course, the physical circuit ought also to have supply bypassing at the op amps etc.) - and also add on, following Application Hint guidance, model components to analyse required op amp output currents. Maybe, for example, the actual circuit omits such things as DC blocking capacitors which would not, in my view, be a good idea.
(My analysis so far has been constrained to resistor noise generation and op amp output current demands. I've not examined other aspects such as stability.)
You are at an advantage - you have the physical circuit. Look at it and tell us what you think.
Were I to design an input buffer for the NC500 I'd be much more focused on how to lower the size of the resistors in the feedback network. I've already pointed to references as to how that might be achieved.
Once again, if you identify any errors in my analysis or thinking I welcome the correction. We are all hear to learn. What's not useful is sitting there saying "tell me the answer" or erroneous technical discussion (not even to mention the rest of the subjective babble).
PS: if you want another reference reading as to the discussion of noise relating to such "47k resistors" (not a good label but useful shorthand for the topic at hand) purchase Samuel Groner's article for Linear Audio relating to his low noise instrument amplifier. It will cost you about £3 and is well worth reading. The first part of section 4 relates to this topic but the entire article is well worth reading.
You can spend some of that time on building me an AB or ABX test box instead.
Productive use of time and helping bring some serious tests to the table. 😉
Boggit has already said what circuit he's going to be using. The schematic has been posted on this thread already. Did you not read anything that's been said on this thread? I'm not sure why you are trying to imply you had a part of any contributions what so ever with the development of any buffer boards just because you read the NC500 data sheet.
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"Going to be using"
Future tense. My reference was to what he is using. And the full schematic, not one with items omitted "for clarity".
And I am not implying anything at all. Your imagination runs wild...
Future tense. My reference was to what he is using. And the full schematic, not one with items omitted "for clarity".
And I am not implying anything at all. Your imagination runs wild...
Well you keep babbling on about buffer designs when a solution as well as measurements have been provided on this thread already. Colin has confirmed that he has tried this circuit and it works great. He's making a new board based on it. End of story.
I've also built an input board based on this circuit months ago. So unless Colin can come up with a better circuit, I think this issue is settled.
"Settled". In your opinion. Glad you will now be leaving the discussion. It will leave room for someone to contribute in a more meaningful way.
