active shielded speaker cables - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 9th April 2007, 11:02 AM   #11
diyAudio Member
 
sunrise's Avatar
 
Join Date: May 2005
Location: delta quadrant
Send a message via ICQ to sunrise
it can also be discrete but if i use lets say mosfets they can't have input higher than 15-18V i think...so it is a question what to use that would be able to consume +/- 50V at the input...it seems to me it is a problem and i don't have any ideas what to use,....
__________________
when you burn it - burn it good
  Reply With Quote
Old 9th April 2007, 12:25 PM   #12
phn is offline phn  Sweden
diyAudio Member
 
phn's Avatar
 
Join Date: Oct 2004
I cannot see how you can remove the capacitance.

I probably oversimplify things here. But you can only lower the capacitance, and when you do you increase inductance.

Capacitance you have to deal with in the active components. And then you have the capacitance load of the loadspeakers. The latter should alone make whatever capacitance of your cables irrelevant.
  Reply With Quote
Old 9th April 2007, 12:43 PM   #13
diyAudio Member
 
sunrise's Avatar
 
Join Date: May 2005
Location: delta quadrant
Send a message via ICQ to sunrise
http://www.iop.org/EJ/article/0957-0...st6_11_004.pdf
phn - look at this link above....this is how they do it with instrumentation....the problem is that i have higher input signal in loudspeaker cables....
that is why i need that partucular opamp (discrete or integrated doesn't matter).....

the capacitance of the cable is still there - you can't remove it physically doing this way but at least you do not have the voltage to charge that capacitor....
the use it in signal trasmission and in measuring eqipment - i want to use the same principle in speaker cables and in interconnect cables....

i need suggestions what to do with that opamp i need - for interconnect cables it is simple - but for the speaker cables i need opamp that can work with +/-50V input signal for my power amplifier.....
__________________
when you burn it - burn it good
  Reply With Quote
Old 9th April 2007, 01:10 PM   #14
phn is offline phn  Sweden
diyAudio Member
 
phn's Avatar
 
Join Date: Oct 2004
The problem with coax only concerns high-bandwidth transfer. We talk gigahertz here. It's misfortunate that DVD-A and other formats are called high resolution. That's nothing but marketing. Audio is the same low-bandwidth world it has always been. You are chasing ghosts here for all I care.

"Power chips" like the LM3886 easily handle +/-50V.
  Reply With Quote
Old 9th April 2007, 02:00 PM   #15
diyAudio Member
 
sunrise's Avatar
 
Join Date: May 2005
Location: delta quadrant
Send a message via ICQ to sunrise
o.k. but i have learned from my experience that when working in audio you have to chase some gosts from time to time.....
i don't care - i want to see if this thing will affect the sound.....

LM3886 can handle +/-50V at the input....i will see that in datasheets....if this is true and if they are unity gain stable than i have solved my problem..
__________________
when you burn it - burn it good
  Reply With Quote
Old 9th April 2007, 02:04 PM   #16
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Everybody loves Sunrise...i love too.


I am glad to see you back to activity.

Good research about cables.....hehe.

You've got a friend on me!

regards,

Carlos
__________________
A Darlington audio amplifier, a toy for your weekend enjoyment; https://www.youtube.com/watch?v=yk0qvkwsAOY, No overshot; https://www.youtube.com/watch?v=CEgK4l0MH8k
  Reply With Quote
Old 9th April 2007, 02:15 PM   #17
diyAudio Member
 
sunrise's Avatar
 
Join Date: May 2005
Location: delta quadrant
Send a message via ICQ to sunrise
thanks Carlos.....

i can't see anywhere that LM3886 is unity gain stable and also i can't see that it can withstand +/- 50V swing of input voltage...
maybe i don't see right ... advise ??
__________________
when you burn it - burn it good
  Reply With Quote
Old 9th April 2007, 02:39 PM   #18
phn is offline phn  Sweden
diyAudio Member
 
phn's Avatar
 
Join Date: Oct 2004
My mistake. I didn't think you were talking about 100V p-p input.
  Reply With Quote
Old 9th April 2007, 02:50 PM   #19
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Radio frequency coaxial cables are normally low capacitance units


As they will need to receive frequencies up to 1 Gigahertz travelling inside..you can imagine how problematic will be capacitance in that sittuation...losses will be enormous.

They are, normally, low impedance cables..so, the pre-amplifier will need to work in a very low impedance and the amplifier input will need some resistance to ground to match.

Have you tried Radio frequency cables?

Distance from the inner conductor related to the shield is very big...resulting very low capacitance.

regards,

Carlos
__________________
A Darlington audio amplifier, a toy for your weekend enjoyment; https://www.youtube.com/watch?v=yk0qvkwsAOY, No overshot; https://www.youtube.com/watch?v=CEgK4l0MH8k
  Reply With Quote
Old 9th April 2007, 03:17 PM   #20
Nordic is offline Nordic  South Africa
diyAudio Member
 
Nordic's Avatar
 
Join Date: Sep 2005
Alot of chips will accept inputs up to the rail voltage... in fact I don't think I worked with one that didn't so far....
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Shielded cables - success Brit01 Tubes / Valves 10 10th August 2009 04:08 PM
cables for diy amps, preamps, and speaker cables ... paulspencer Solid State 5 3rd August 2004 07:14 AM
shielded cables in enclosure MBK Solid State 25 16th March 2004 03:31 AM
Shielded cables? Dxvideo Chip Amps 6 22nd January 2004 06:54 AM
Shielded speaker suppliers bimbla Swap Meet 0 24th November 2002 07:41 AM


New To Site? Need Help?

All times are GMT. The time now is 10:21 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2