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From a thread in the Market Place where a pair of Charge Coupled filters were being offered, this OT discussion emerged. I thought it might make sense to preserve it as a stand alone as I am sure others will also wonder about the subject. It has been covered in detail on numerous DIY threads, but the technology in general hasn't really been discussed. Perhaps those with experience could chime in here.
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I have a dumb question, why is there a battery on the board?
Thanks,
Nick
DC biasing?Quote:
Originally Posted by NickH
Modern Technology - some of the higher end JBLs use a technique called Charge Coupling ...Quote:
Originally Posted by NickH
you bias the crossover with the 9v battery -
lots of info on that and circuit descriptions in other threads on this site.
Ed Meitner suggested to Greg Timbers that he try baising the capacitors in his SOTA loudspeaker designs. Greg tried it, compared it to stock and has never looked back.
If you don't know who Ed is here are a couple links if interested:
http://www.emmlabs.com/
http://www.stereophile.com/content/e...audio-maverick
Harley: Where do you think digital audio sound quality stands in relation to analog?
Meitner: Delta-sigma [oversampling] converters get very close, and in a lot of ways exceed analog. But having said that, there were fleeting magic moments with a turntable when the cartridge was just right. But the next day it may not do the same thing anymore. At least with digital we can have more stability and repeatability.
What's sad about it is that a lot of the digital transfers on CDs were done before the advent of delta-sigma converters and have gone through some horrible, horrible processing. I have a feeling that this is part of history lost.
Harley: The poor digital transfers may be the only surviving sources for future generations. The analog tapes may be lost or destroyed.
Meitner: That's right. And recordings made digitally still went through brickwall filters and other stuff. That's the grief of digital audio. But the future is quite rosy.
There is a comprehensive explanation here:
http://www.lansingheritage.org/image...500/page10.jpg
http://www.lansingheritage.org/image...500/page11.jpg
http://www.lansingheritage.org/image...500/page12.jpg
It's from this thread:
http://www.audioheritage.org/vbullet...sed-Capacitors
Here are some simulations to demonstrate the voltages behavior
http://www.audioheritage.org/vbullet...l=1#post252588
Here are some infos about capacitor behahior
http://www.audioheritage.org/vbullet...l=1#post252124
This is going to take a lot of reading.
Thanks for the links.
Good thread ,have a lot to study.