New Posts New Posts RSS Feed - Capacitance
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Welcome to the Graham Slee Audio Products Owners Forum

 

Open to all owners plus those contemplating the purchase of a Graham Slee HiFi System Components audio product and wishing to use this forum's loaner program: join here (Rules on posting can be found here)

This website along with trade marks Graham Slee and HiFi System Components are owned by Cadman Enterprises Ltd


Capacitance

 Post Reply Post Reply Page  <1234>
Author
morris_minor View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 27 Mar 2012
Location: Surrey
Status: Offline
Points: 6015
Post Options Post Options   Thanks (0) Thanks(0)   Quote morris_minor Quote  Post ReplyReply Direct Link To This Post Posted: 16 Mar 2016 at 5:24pm
Originally posted by Drewan77 Drewan77 wrote:

So a 1.5metre Lautus interconnect @55pf/m should fit the bill nicely - maybe Paul should add this to his loan items? Wink
Excellent idea, Andrew! Save for a couple of optical cables, my study system is exclusively cabled with Graham's bits of wire, and it sounds bloody marvellous . . Big smile
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
Back to Top
Paul H View Drop Down
Senior Member
Senior Member


Joined: 13 Mar 2016
Location: Nottingham
Status: Offline
Points: 121
Post Options Post Options   Thanks (0) Thanks(0)   Quote Paul H Quote  Post ReplyReply Direct Link To This Post Posted: 16 Mar 2016 at 5:44pm
Originally posted by Graham Slee Graham Slee wrote:

With all due respects to the good people over at Steve Hoffman, they
might not have my 43 years turntable user and electronics design
experience, and I doubt any can match Denon's 106 years!

And I have also heard of the "all capacitors are evil" witch hunt.

You can doubt me as much as you want at me suggesting you've insufficient capacitance but the capacitance is there for a reason.



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
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.
Back to Top
DaveG View Drop Down
Senior Member
Senior Member


Joined: 26 Oct 2014
Location: London
Status: Offline
Points: 479
Post Options Post Options   Thanks (0) Thanks(0)   Quote DaveG Quote  Post ReplyReply Direct Link To This Post Posted: 16 Mar 2016 at 6:36pm
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 loungeTongue.

Mark my words it'll be the built in phono stage.

Smile



Edited by DaveG - 16 Mar 2016 at 6:37pm
Dave

Michell Gorbe + HR PSU -> Cadenza Bronze -> SME V -> Elevator -> Accession -> Proprius -> B&W CM6 s2 | Cusat 50 & Spatia cables ->
Back to Top
Graham Slee View Drop Down
Admin Group
Admin Group
Avatar
Retired

Joined: 11 Jan 2008
Location: South Yorkshire
Status: Offline
Points: 16298
Post Options Post Options   Thanks (1) Thanks(1)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 16 Mar 2016 at 6:42pm
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)

Ortofon Blue HF Response at different capacitive loads

The 137.2pf is what I'm guessing you probably have now, based on the Denon being 100pf - but who knows?
That none should be able to buy or sell without a smartphone and the knowledge in how to use apps
Back to Top
Paul H View Drop Down
Senior Member
Senior Member


Joined: 13 Mar 2016
Location: Nottingham
Status: Offline
Points: 121
Post Options Post Options   Thanks (0) Thanks(0)   Quote Paul H Quote  Post ReplyReply Direct Link To This Post Posted: 16 Mar 2016 at 9:22pm
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
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.
Back to Top
Paul H View Drop Down
Senior Member
Senior Member


Joined: 13 Mar 2016
Location: Nottingham
Status: Offline
Points: 121
Post Options Post Options   Thanks (0) Thanks(0)   Quote Paul H Quote  Post ReplyReply Direct Link To This Post Posted: 16 Mar 2016 at 9:49pm
Originally posted by DaveG DaveG wrote:

I found out my room is apparently exactly the worst possible shape & size

Ah, you're using the same room as me then. Small and square...
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.
Back to Top
Richardl60 View Drop Down
Senior Member
Senior Member


Joined: 04 Nov 2014
Location: Yorkshire
Status: Offline
Points: 1468
Post Options Post Options   Thanks (0) Thanks(0)   Quote Richardl60 Quote  Post ReplyReply Direct Link To This Post Posted: 16 Mar 2016 at 10:37pm
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
Back to Top
 Post Reply Post Reply Page  <1234>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.01
Copyright ©2001-2018 Web Wiz Ltd.

This page was generated in 0.141 seconds.