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Post by Deleted on Apr 28, 2012 11:23:01 GMT
I recently made a music room and to one side I have a nice stone table. I put my out of use record deck on it as an ornament really but got the urge to use it occasionally. Problem is it sits about a 4 metre cable run from the pre-amp etc. So I dug my Michell out of storage and then decided to have a look inside, thought the pics might be interesting to some.   That traffo is massive, about 5" and I see it's core is filled as per Mike's recent posts.  This is it in place. They match well as the covers are stainless and the ends are black, I think, acrylic same as the deck. It sounds pretty good considering the liberties with the long cable but at least it is the amplified signal not the output direct from the MC cartridge. Syd |
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mrarroyo
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Post by mrarroyo on Apr 28, 2012 12:40:02 GMT
Very nice, but isn't that platter a bit big for cd's?  |
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Post by Deleted on Apr 28, 2012 13:36:24 GMT
Very nice, but isn't that platter a bit big for cd's? Mass is all Miguel, although I only seem to get scratchy noises from my later CDs  Syd |
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XTRProf
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Post by XTRProf on Apr 28, 2012 15:35:46 GMT
Wow, all highend Dale high precision 0.1% resistors. Oh, you should be playing a LD on it too ................. Universal playe is quite the norm now.  Btw, you never describe the sound in a word! |
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joethearachnid
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Post by joethearachnid on Apr 28, 2012 23:21:18 GMT
Well I think that puts the phono preamp I'm planning on building to shame pretty effectively. I think the trafo from my one would fit inside that toroid about 18 times.  I can understand why the heavily filtered and regulated PSU for a phono preamp but why does the transformer have to be so gigantic? -JoetheArachnid |
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Post by Deleted on Apr 28, 2012 23:59:18 GMT
Dunno Joe but I'd forgotten about it for quite a while so when I started to lift it out of the cupboard I thought for a minute the rubber feet had stuck down! The other unit feels light as a feather in comparison but it all seems nicely built.
Syd
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Will
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Post by Will on Apr 29, 2012 9:43:26 GMT
Hi Syd, Nice photo's of some nice kit! Best thing about it is that Fran's will have the circuit diagram of the phono stage sorted out for just after lunch  On the big traffo front, looking at the bank of capacitance after gives an indication of the amount of current draw on power up, plus current demand capability. Does the PSU supply the phone and the record player? |
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Post by Deleted on Apr 29, 2012 10:31:35 GMT
On the big traffo front, looking at the bank of capacitance after gives an indication of the amount of current draw on power up, plus current demand capability. Does the PSU supply the phone and the record player? Hi Will Good to see you posting, hope the pressure's easing! The PSU supplies only the pre-amp, the deck motor goes directly to the mains:  I don't know why the PSU is so hefty, I just bought this at the time because of good reviews and it looked nice One thing I forgot to mention in the first post is that if I leave the power amp on but switch the phono amp off there is a switch off thump, not huge but I'd rather it wasn't there. Don't know if it would be possible to modify it. Maybe Frans will see a flaw whilst reverse engineering Syd |
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Will
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Post by Will on Apr 29, 2012 11:29:35 GMT
Hi Syd,
Yep, things are certainly easing up now, thanks!
I've seen some turntable PSU's with massive traffo's in them (like the aftermarket ones for that technics deck that's popular) as it responds well to having a motor supply that is very much in control.
As your phono is the only thing supplied from the PSU, then I can imagine that Michell wanted to ensure that the circuit was never starved!
On the anti-thump, something like Alex's small circuit in the AK class A would be useful, but would need a better understanding of your current circuit, and what supplies are available.
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Post by Deleted on Apr 29, 2012 18:20:35 GMT
Judging from the pics it already has a mute circuit but think it might kick in too late.
a simple relay, 1 transistor 2 resistors and a zener diode can be retrofitted and possibly get rid of the problem.
All I need to know is what voltages are present on the input connector (+Ve and -Ve)
Also is the thump immediate at switch off or after a few seconds.
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Post by Deleted on Apr 30, 2012 10:29:34 GMT
Hi Frans
The voltage is +22 and -21, supposed to be 22V both but my meter jumps from 20V scale to 600V so not very accurate.
Delay before thump is 5 seconds. It will be great if your mod works, thanks.
Syd
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Post by Deleted on Apr 30, 2012 15:39:53 GMT
Here you are Syd,  custom design ;D If you need any help PM me. Maybe one of the resistors may need a change of value to switch off even faster when needed, but I suspect it'll work O.K. |
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Post by Deleted on Apr 30, 2012 16:04:19 GMT
Thanks Frans but I think you mean WHEN .... very tactful. I'll start searching for the parts tonight, then you'll hear from me Syd |
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Post by Deleted on May 1, 2012 21:49:52 GMT
Sorry Chong missed this one! That's easy "analogue" Syd |
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Post by Deleted on May 2, 2012 23:10:22 GMT
Just a footnote to thank Frans, he came up with a very neat solution that has transformed the switch off experience , not to mention the very quick replies to my daft questions! I need to make a tidier board but here it is for now:  Syd |
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XTRProf
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Post by XTRProf on May 3, 2012 0:56:03 GMT
Sorry, those wires normal ones? Should use OCC. Not very expensive stuff. |
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Post by Deleted on May 3, 2012 2:15:27 GMT
But could he pick the difference in a DBT ? |
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Post by Deleted on May 3, 2012 9:39:14 GMT
Certainly not  They are lengths of Jon's recently offered stock. As I recall Teflon covered etc. If Jon reckons something's good that's good enough for me  What's OCC? No  As far as I understand it the audio side is totally unaffected by this mod, nothing interferes with the signal path whilst powered up and running. Syd
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XTRProf
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Post by XTRProf on May 3, 2012 12:51:48 GMT
Ohno Continuous Casting No need DBT! It's objective specs and explanation and no subjectiveness. So there is nothing objectivists can disagree with. Check it out here .............. www.furutech.com/news/cables_explained.pdfBut it also depends on whether you like that sound or not. Oops! ;D |
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Post by Deleted on May 3, 2012 15:51:16 GMT
Very interesting but I've tried very expensive mains cables and I'm more of "'good quality' is fine" for mains now. Interconnects I can hear up to a point but again my store cupboard is quite filled with 'high-end' versions. The ones I made recently, mainly for reasons of being easier to keep tidy 'round the back', I cannot honestly tell the difference. My progression on electronics I am happy with. Frans and Alex' HAs are as good as it gets to my ears, each has a sound I like very much for different uses and I can't see me ever feeling the need to change them. I'm keen to hear Alex/Wills new amp especially to compare it with my current main setup. All that said I know I lag well behind the aural abilities of many of the guys on here and I respect their abilites and quite often follow them for the satisfaction of knowing I have the current best gear, SQ wise, if that makes sense. I certainly know my systems' sound is streets ahead of where I started. Ramble over Syd |
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They are lengths of Jon's recently offered stock. As I recall Teflon covered etc. If Jon reckons something's good that's good enough for me 
