Improving damping factor for OTL - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 22nd November 2004, 02:49 PM   #1
diyAudio Member
 
Join Date: Dec 2003
Location: hong Kong
Send a message via ICQ to ackcheng
Default Improving damping factor for OTL

Got interesting in improving the damping factor for OTL from transcendent OTL T8

Here is the notes form Transcendent site
"Letís look at the Transcendent T8 as an example. It uses 8, EL509 tubes in push-pull. Each 509 has a plate impedance of about 150 ohms. 150 ų8 = 18.75 ohms. This is unacceptable. Negative feedback is employed to achieve proper performance. The amplifier uses 33 dB of negative feedback which reduces the output impedance to 0.4 ohm thereby achieving outstanding woofer control and the ability to drive 4 ohm speakers. This specification was verified by Stereophile when they reviewed the amplifier."

Actually, I don't know how is 0.4ohms derived but guess there are 2 ways we can improve the drivability of the drivers
1. Use more output tubes
2. Connecting 2 drivers in series and increase the impedience

Am I correct? Can someoe kindly tell me how is 0.4ohm derived?
  Reply With Quote
Old 22nd November 2004, 03:56 PM   #2
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
33dB = 44, so the open loop output impedance of 18.75 Ohms is divided by the amount of negative feedback to give 0.4 Ohms.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  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
Damping factor in DIY amp jaya000 Solid State 25 25th September 2008 12:27 PM
Improving P3A damping factor palesha Solid State 4 3rd May 2006 11:38 AM
Damping factor Cro maniac Chip Amps 29 8th May 2004 02:16 PM
Damping factor thylantyr Solid State 9 14th March 2003 07:37 AM
Damping factor..????? emarald Solid State 15 30th January 2003 03:41 PM


New To Site? Need Help?

All times are GMT. The time now is 01:29 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