But not suprising, given JC's low opinion of them that the JC3 is suboptimal in MM mode. Then again not many people in the market for a 3K+ phono stage even consider MM. The shame is I am convinced that a lot of people* don't realise what they have missed out on.
*where people means us group of strange deluded individuals who still have vinyl collections 🙂
*where people means us group of strange deluded individuals who still have vinyl collections 🙂
Dude, ridiculas, you've been the black cloud over this thread since you decided to scribble your ravings. So cut the whining, and look at your own posting history.
Several of the solder joints look a little thin, but that's it. Mark pointed out the oddities, but that's all they are. Heck, I'm sure John isn't even involved with the manufacturing.
Several of the solder joints look a little thin, but that's it. Mark pointed out the oddities, but that's all they are. Heck, I'm sure John isn't even involved with the manufacturing.
OK guys, here is the schematic. We make this design cheap enough today, that if you want to duplicate it, waste your time. '-)
Yes, Parasound is my 'cost-effective' version of what I design. I can't afford any better, can you? I don't completely approve of everything that the manufacturers do to save a little money here and there, but mostly they conform to our wishes. Personally I use SN62 Cardas solder for everything that I personally make, and better then FR-3 board material, including Teflon for the Blowtorch, but you know, extra care costs time and money, and THEY DON'T SCRAPE THE LEADS! '-)
Yes, Parasound is my 'cost-effective' version of what I design. I can't afford any better, can you? I don't completely approve of everything that the manufacturers do to save a little money here and there, but mostly they conform to our wishes. Personally I use SN62 Cardas solder for everything that I personally make, and better then FR-3 board material, including Teflon for the Blowtorch, but you know, extra care costs time and money, and THEY DON'T SCRAPE THE LEADS! '-)
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We changed the input IC to the LME49990 because it sounded just as good (just different) from the AD797 and it was much cheaper to buy.
The Vendetta Research discrete all-fet phono stage is a better circuit, but we had to make do with IC's, so I did my best. The input op amp could be swapped for a fet input IC or even a 5534, but then the moving coil option would be lost.
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The copyright only covers the exact layout of the PC board. I assume Parasound is a registered trademark so you could not use their name to sell clones.
Why bother to label the source and drain of Q2, since it's a symmetric device? And if they're going to bother labeling source and drain, why do it backwards?? The gate is shorted to the source, not the drain! Parasound's draftsman needs a better ERC.
What are the chances we could get someone to substitute Vishay MKP1839347164 at @1.20 for an honest no peeking listen? Past history is zero. 😉
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What would you recommend to replace the OPA2134 Dimitri? I chose this part more than a decade ago to replace the AD712, because it had better offset. I haven't 'subjectively' evaluated anything else for awhile.
1642 Would be a good start. AD released a very nice jfet input opamp recently but can't remember the code. Won't be in dip8 though.
Edit -- Hah! Chris beat me to the punch. IIRC the 2140 is a 1642 binned for DC precision. And thanks, Patrick!
Edit -- Hah! Chris beat me to the punch. IIRC the 2140 is a 1642 binned for DC precision. And thanks, Patrick!
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