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morris_minor
Moderator Group Joined: 27 Mar 2012 Location: Surrey Status: Offline Points: 6015 |
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Bob
Majestic DAC/pre-amp Accession MC/Enigma, Accession MM, Reflex M, Elevator EXP, Era Gold V Solo ULDE, Novo, Lautus USB and digital, Libran balanced, CuSat50 2 x Proprius + Spatia/Spatia Links |
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Paul H
Senior Member Joined: 13 Mar 2016 Location: Nottingham Status: Offline Points: 121 |
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Not doubting you at all, Graham. (I wouldn't dare be so rude and presumptuous.) I was merely expressing frustration at the advice that led me down a path to low capacitance cables. Me, I know nothing: I just go by the advice I can find. If I'd known I'd be able to tap into the expertise of someone who makes this kit for a living, I'd certainly have sought your advice first! I suspect that all that's happened is that I've taken their advice a little too much to heart and gone completely over the top, as is my nature. I confess to still being a little confused by it all. I'm absolutely no electrical engineer and the advice I was given was that I should be shifting that peak out of audible range which, for me, will be above 16kHz. That's all I'm trying to achieve. Your suggestion that I need some capacitance makes sense and doesn't conflict with previous advice: it's how much that seems to be at issue. I've been trying to get it down to as close to 150pF as I can in the expectation that this will shift the peak "out of harm's way". You're suggesting I need more, that's all. Edited by Paul H - 16 Mar 2016 at 6:06pm |
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ProJect 1Xpression Carbon UKX w/ Ortofon 2M Black; Arcam Alpha 7 CD player; Graham Slee Revelation M pre; Denon PMA 355UK amp; Epos K1 speakers; Blue Jeans LC-1 interconnects. Room: 2.9m x 3.1m.
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DaveG
Senior Member Joined: 26 Oct 2014 Location: London Status: Offline Points: 479 |
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Perhaps worth a mention the BJ cable is quoted as pF/foot which works out around 40pF per metre. So still low but not incredibly so as I first thought. Probably not much wrong with it in that respect. I think all you've done is focus on one particular aspect that may or may not be the answer. We all do the same - my latest is room acoustics. I found out my room is apparently exactly the worst possible shape & size, so I'm experimenting with room treatment. Failing that I'm waiting until next door go on holiday & ...ermm.. knocking through into their lounge.
Mark my words it'll be the built in phono stage. Edited by DaveG - 16 Mar 2016 at 6:37pm |
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Dave
Michell Gorbe + HR PSU -> Cadenza Bronze -> SME V -> Elevator -> Accession -> Proprius -> B&W CM6 s2 | Cusat 50 & Spatia cables -> |
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Graham Slee
Admin Group Retired Joined: 11 Jan 2008 Location: South Yorkshire Status: Offline Points: 16298 |
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Hi Paul, shift it "into harm's way" and it will work.
Here's a plot of the electrical response with different total capacitive loading. (remember, this is not the total electrical and mechanical response) The 137.2pf is what I'm guessing you probably have now, based on the Denon being 100pf - but who knows? |
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That none should be able to buy or sell without a smartphone and the knowledge in how to use apps
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Paul H
Senior Member Joined: 13 Mar 2016 Location: Nottingham Status: Offline Points: 121 |
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What assumptions did you make in order to calculate 132pF, Graham? Here are my calcs:
tonearm: 25pF (based on a comment of yours I read somewhere, that this is a good guesstimate for tonearms) cable: 12.2pF per foot x 2 feet = 24pF Amp: either 100pF or 220pF That gives me a total of either roughly 150pF or 270pF depending on what the amp's rating is. At your suggestion, I've swapped out the 2 foot cable for the 3 foot cable I have, which gives me a total figure of roughly 37pF for the cable. This increases my "score" to either 160pF or 280pF. Both are within Ortofon's suggested range of 150-300pF. I can add further capacitance by putting my mono switch back in. No idea what capacitance the switch would add but another length of cable would add in another 24pF. To be honest, part of the reason I was drawn towards introducing a pre-amp was the ability to alter the capacitance of the amp and simply knowing what capacitance it was adding. (I had been looking at other manufacturers' products that featured the ability to adjust settings but in the end decided against because I doubted I'd hear any noticeable difference. My thinking is: if I'm going to spend £x on an amp, I'd rather it all went on quality parts, design and construction than on bells and whistles. That's what's most likely going to give me an appreciable improvement.) Edit: I really must take a moment to thank you for taking the time to offer up this advice and information. It really is appreciated. Edited by Paul H - 16 Mar 2016 at 9:27pm |
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ProJect 1Xpression Carbon UKX w/ Ortofon 2M Black; Arcam Alpha 7 CD player; Graham Slee Revelation M pre; Denon PMA 355UK amp; Epos K1 speakers; Blue Jeans LC-1 interconnects. Room: 2.9m x 3.1m.
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Paul H
Senior Member Joined: 13 Mar 2016 Location: Nottingham Status: Offline Points: 121 |
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Ah, you're using the same room as me then. Small and square... |
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ProJect 1Xpression Carbon UKX w/ Ortofon 2M Black; Arcam Alpha 7 CD player; Graham Slee Revelation M pre; Denon PMA 355UK amp; Epos K1 speakers; Blue Jeans LC-1 interconnects. Room: 2.9m x 3.1m.
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Richardl60
Senior Member Joined: 04 Nov 2014 Location: Yorkshire Status: Offline Points: 1468 |
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Looked at the blue jeans cables and interestingly don't make any reference as to what the cables are made of (unless I missed it). I will stick with my moving cold and avoid the issue!
Richard |
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