ESL Direct Drive - 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 1st October 2008, 05:30 PM   #1
Atom666 is offline Atom666  Canada
diyAudio Member
 
Atom666's Avatar
 
Join Date: Oct 2005
Location: Toronto, Canada
Default ESL Direct Drive

I just wondered if anyone had ever built the Alan Kimmel/ David Lucas direct drive amplifier?
Thanks
Andrew
  Reply With Quote
Old 2nd October 2008, 07:25 PM   #2
diyAudio Member
 
Join Date: Nov 2005
Location: Southern Germany
Hi,

i would never put my fingers on such high voltage sources, by doing on my own, but its interesting.

In about 4 weeks i will listen to my ESL driven by:

www.innoxx.com

Capaciti
  Reply With Quote
Old 3rd October 2008, 09:07 AM   #3
Calvin is offline Calvin  Germany
diyAudio Member
 
Calvin's Avatar
 
Join Date: Nov 2004
Location: close to Basel
Hi,

had not the sand boxes but the KR845-Tube running at 2kV and will probabely soon modify the anode resistor to an active current source and later the tube to a new 5kV-KR tube.
Besides beeing faster, working without global feedback and not needing any fancy cascading of transistors -which is notorious against breakdown- the tube can deliver higher currents into the load! The rather small 25mA of the Inox will only drive rather small capacitances, hence small or segmented panels. The current defines the power bandwidth limit of the amp which can be as low as 5kHz!! To achieve sufficient power bandwidth is one of the key-problems of solid state HV-amps! So I assume, that the amp might work with the capacitis -which are of the segmented type-, but its a way not sufficient amp to drive something like a MartinLogan-style panel. You need something more beefy to drive those babies. This issue is adressed in the McKean/Lucas articles, you can find in an older thread here.
The 1kV anode voltage and the low current of 12mA of the Lucas-amp are designed to drive headphones with their low voltage and current needs. A loudspeaker panel needs more than that, typically >2kV and >25mA. Without a beefier output stage design the Lucas would only be able to drive a speaker panel to a middle volume level, before heavy distortion sets in.

jauu
Calvin
  Reply With Quote
Old 3rd October 2008, 02:28 PM   #4
Atom666 is offline Atom666  Canada
diyAudio Member
 
Atom666's Avatar
 
Join Date: Oct 2005
Location: Toronto, Canada
Calvin
I'm not sure we are talking about the same Lucas amplifier. The Kimmel /Lucas amplifier used 6HV5 compactron tubes in the output stage. I have the schematic somewhere if I can find it I will post.
Thanks
Andrew
  Reply With Quote
Old 3rd October 2008, 02:55 PM   #5
diyAudio Member
 
luvdunhill's Avatar
 
Join Date: Jul 2006
Calvin:

Searches are turning up nothing. Can you provide a reference to this article?
  Reply With Quote
Old 4th October 2008, 05:31 PM   #6
diyAudio Member
 
Join Date: Jan 2008
Location: Toronto and Delray Beach, FL
For about 15 years, I ran a Sanders-like amp with a 2400 volt B+ into Dayton-Wright elements in an array and later, Dayton-Wright speakers. If a table radio is a 5, good speakers a 10, then ESL with transformers at a 20 and direct HV drive is a 25... to my ears.

Direct drive is clearly the better way. Clearly, at least with Dayton-Wrights and their otherwise pretty good transformers. But even with transformers, you are way ahead of the dynamic speaker crowd.

Of course, dangerous! But I never had a shock that I can recall.
__________________
Dennesen ESL tweets, Dayton-Wright ESL (110-3200Hz), mixed-bass Klipschorn (35-110), and giant OB using 1960's Stephens woofer (20-35); Behringer DSP. HiFi aspirations since 1956
  Reply With Quote
Old 5th October 2008, 08:09 AM   #7
Calvin is offline Calvin  Germany
diyAudio Member
 
Calvin's Avatar
 
Join Date: Nov 2004
Location: close to Basel
Hi,

i thought of amp in the thread "horizontal deflection (or high voltage type) transistors to direct drive ESLs", opened by bigwill in 2006.

jauu
Calvin
  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
direct drive ribbon amp hancock Pass Labs 39 28th November 2012 08:55 PM
Direct Drive fun!!! Cobra2 Analogue Source 32 20th January 2007 02:23 AM
Another direct drive thread maudio Planars & Exotics 18 25th June 2006 06:53 PM
Technics direct drive SL-D35 Jason1976 Analogue Source 1 15th May 2006 06:28 AM
ESL Direct Drive SS amp jgwinner Solid State 34 30th August 2004 06:42 PM


New To Site? Need Help?

All times are GMT. The time now is 03:00 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