Listen, Slim.a you seem to have some beef with me & I don't know what it is? Have I upset you somewhere? I'm just giving the information fairly as I know it & not trying to give any mis-information whatsoever! Let people read those threads & make up their own minds. Audioengr has a business selling expensive USB units that the Musiland threatens - I do not - you figure who is likely to have a biased opinion
I'm not going to get into the same argument with you as I did with him but just read the whole thread for a fair report on it not your skewed one-sided reporting of just his comments.
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Originally Posted by slim.a  Jkeny, the 300 ps is a best case theoretical figure given at the pin out of the FPGA. It doesn't say much about the real jitter of the unit.
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These are
theoretical maxima, slim - stop trying to make the words fit your world view. EDIT: So in fact it is a worse case figureYes, I agree the real jitter of the unit isn't mentioned but look at the graphs & do a search on audioasylum under fmak as I suggested.
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As for the link you gave me, Steve Nugent (audioengr / the designer of the Emirical off Ramp and a respected engineer) disagrees with your conclusions. He has already used FPGAs in his designs but only in non critical parts.
Below is a quote from an answer he gave you :
RE: Musiland 01 USD at 192k - audioengr 11:44:21 09/05/09 (3)
In Reply to: RE: Musiland 01 USD at 192k posted by jkeny on September 01, 2009 at 13:12:31
If you simply look at the output buffers on Xilinx PGA's and other programmable parts, you will find that they are generally a compromise. Really large buffers are required with dedicated power pins in order to get clean, fast, noise-free edges. This is what is needed for low jitter. These parts with hundreds of pins usually have maybe 4 power and 6-8 ground pins. The buffers cannot drive 50 or 75 ohms loads directly. There is no way that this can compete with simpler more discrete logic with more power pins and less sharing of the power currents. Highly integrated parts often have these shortcomings. Lots of functionality, but the signal integrity and drive may be issues in your circuit. |
If you are going to quote him why don't you also quote my reply to him & his final answer - it seems to me that you are keen to mis-represent me?
Here's what I said in response: [QUOTE]
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| I don't know about other FPGAs but this particular FPGA has 13 supply pins of which 6 (Vcco) are dedicated to output buffer stages. John Swenson did a good theoretical analysis of the potential jitter. Until someone measures the jitter accurately we are just guessing, however. |
To which he replied with just an opinion & nothing to back it up
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| I use Xilinx and I have not been impressed with the performance of their output buffers. |
Listen, I'm not going to get into this s**t - you've got your agenda - I'm just representing my research on the Musiland - take it or leave it - I'm not interested in revisiting old ground!
I suggest you read John Swenson's views, an unbiased non-manufacturer with technical no-how & be careful of sources with vested interests!
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| Jkeny, I really don't understand why you spread false information about the Musiland and discard everything that is being said to you. |
I don't discard anything that is being said to me about the Musiland - I tanked John Swenson for his fair & frank summary of the unit in which he said 300ps is not good performance in his eyes!
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| The thread is not named Musiland 01 USD at 192k by audioengr but Musiland 01 USD at 192k y the way. And when you read the thread, you understand that audioengr disagrees with you. What did you feel the need to rename the link ? |
Jeesus, slim, I didn't rename the link I simply copied it & that is what it came over as OK, christ you have got some bee up your arse, haven't you?
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| I am not saying the Musiland is bad. It is a very good unit for $75. But it is bad to spread false information and each time I tried to verify your sources, there were inconsistencies. |
Don't accuse me of spreading false information - you haven't shown any inconsistencies with my sources - you have just quoted snippets out of context for your own ends - so who is spreading the false info?
I will say it again, I'm a fan of the Musiland - I like the sound - I have reported as much of the technical information as I feel is appropriate to this forum (I have read the Xilinx datasheet & background papers about the jitter performance of their FPGAs so I know a lot more about it than you have demonstrated you know about the working of the M2tech). If I have made any mistakes, I apologise but don't accuse me of spreading mis-information - I have absolutely no need to do this.
I & others who wanted to look at & discuss the technology behind the Musiland, got a lot of stick on Diyhifi & in the thread you mentioned from the owners of companies who purvey expensive USB solutions. So a lot of mis-information was spread by them about this dirt cheap USB asynchronous 24/192 Chinese "piece of crap" according to them. You tell me who is mis-representing the facts?
