| TubeDAC from Sheldon Stokes with PCM63 - Click HERE for Original Thread |
| stef1777 |
Hi Folks!
I built years ago the TubeDAC from Sheldon Stokes. It use two PCM63-K Burr Brown DAC and 6DJ8 at output stage.
What should do we it? Trash it :dead: , use components to build something else or tweak it to obtain something better? |
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| GeWa |
Hi Stef1777
I also have built Sheldon's Big Dac in the past and until today I like the sound verry much. As an experiment I replaced the SRPP output stage with a Mu-Stage (input tube 30 and top tube D3a) and this was a great improvement in soundstage and detail.
I would not scrap it, it's a good piece of equipment.
Happy listening
Walter |
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| Elso Kwak |
| quote: | Originally posted by stef1777
Hi Folks!
I built years ago the TubeDAC from Sheldon Stokes. It use two PCM63-K Burr Brown DAC and 6DJ8 at output stage.
What should do we it? Trash it :dead: , use components to build something else or tweak it to obtain something better? |
Hi Steff,
You can improve the digital inputreceiver by placing an AD8561 in front of it. And using the Wildmonkeysects loopfilter for the PLL of the CS8412. Also using a low noise analog supply for the PLL. You can also install my Asynchronous Reclocker. Schematic available on request. And last but not least you can modify the DAC to NON-OS. This will require a 74HC164 to get a normal sound output.
The combined effect of these measures will amaze you!
Though I prefer the TDA1543, the PCM63 is a good DAC similar in sound to the AD1865.
Cordialement,
:cool: |
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| rlim |
Guido,
"3ps rms, 3-sigma."
What does your spec actually mean? Isn't rms a 1 sigma number?
Thanks,
Richard |
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| Guido Tent |
| quote: | Originally posted by rlim
Guido,
"3ps rms, 3-sigma."
What does your spec actually mean? Isn't rms a 1 sigma number?
Thanks,
Richard |
No
sigma relates to distribution of Gausian ditributed phenomena, like noise
rms refers to a "weighting method" method in order to retrieve the enrgy from a random signal
cheers |
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| rlim |
| quote: | Originally posted by Guido Tent
No
sigma relates to distribution of Gausian ditributed phenomena, like noise
rms refers to a "weighting method" method in order to retrieve the enrgy from a random signal
cheers |
Please look up this pdf document and let me know what you think. Unless the pletronics is wrong in their analysis, 1 sigma without deterministic jitter sure sounds like an rms number to me.
http://www.pletronics.com/pdf/Determine%20PK.pdf
Perhaps you can let us know how you did the jitter measurement. That will clarify a lot of my confusion.
Thanks,
Richard |
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| stef1777 |
Thanks for all answers.
I can see that I'll have a lot to tweak when my VRDS10 and DEQ2496 will be finished.... |
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| Guido Tent |
| quote: | Originally posted by rlim
Please look up this pdf document and let me know what you think. Unless the pletronics is wrong in their analysis, 1 sigma without deterministic jitter sure sounds like an rms number to me.
http://www.pletronics.com/pdf/Determine%20PK.pdf
Perhaps you can let us know how you did the jitter measurement. That will clarify a lot of my confusion.
Thanks,
Richard |
Hi Richard
I now see your point
it should be 1 sigma, I'll dig up the typo at the website
thanks |
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