Ideal bias supply? - diyAudio
Go Back   Home > Forums > Loudspeakers > Planars & Exotics

Planars & Exotics ESL's, planars, and alternative technologies

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 27th October 2006, 07:50 PM   #1
diyAudio Member
 
Join Date: Sep 2006
Default Ideal bias supply?

What are the features that make a good bias supply sound good? Would the best bias supply be a single toroidal tranformer?
  Reply With Quote
Old 27th October 2006, 08:37 PM   #2
diyAudio Member
 
Join Date: Apr 2005
Location: Utrecht
Hi,

I can recommend using a conventional Cockroft-Walton-kaskade with a neon oscillator at the output. The neonoscillator is made of a simple neonbulb + resistor with a capacitor parallel. It works like a filter and you can see the amount of charge running to the membrane by the frequency of the neon bulb going on and off.
No need for high power here.
__________________
drs M.J. Dijkstra
  Reply With Quote
Old 30th October 2006, 08:23 PM   #3
diyAudio Member
 
stokessd's Avatar
 
Join Date: Nov 2002
Location: Grantham, NH
A good ESL panel (IE low leakage) should be able to run for many minutes without a bias supply at all. My DIY panels, the Quads, and all the ESL's I've played with play perfectly fine for minutes/hours with the plug pulled after they charge up. There is a slow decrease in SPL as they discharge, but over a few minutes, we're talking fractional dB's.

So given that the bias supply charges the panel through a big-honkin (tm) resistor, and that charging and discharging frequency is closer to geological frequencies than audio frequencies, the bias supply plays a remarkably small roll in overal sound quality of the speaker.

I get a lot of folks asking about what power cables they should use for the original ESL's. I suggest that they pull the plugs and listen and see if they hear any difference. When they don't they should take that "power cord" money and go buy more music.

All that said, the bias supply should be noise free, which implies adequite filtering. I designed a switching supply that works up about 10KHz, which means that I can use slightly smaller caps than a standard 60 Hz (or 50Hz) supply and get way way way better noise filtering because my noise is many octaves above the 120 Hz noise from a sttandard linear supply run from that wall.


Sheldon
  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
ESL Bias Supply Polarity bolserst Planars & Exotics 30 23rd June 2010 01:38 AM
Need a bias supply how?? Original Burnedfingers Tubes / Valves 29 9th February 2009 11:33 AM
Bias supply idea astouffer Tubes / Valves 15 2nd October 2008 04:12 AM
ground of DC bias supply jarthel Tubes / Valves 1 31st May 2007 01:03 AM
Ideal power supply for CDs, DACs etc saczek Power Supplies 2 28th January 2007 12:43 PM


New To Site? Need Help?

All times are GMT. The time now is 07:33 AM.


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