parafeed - Gyrator vs CCS anode load - Page 3 - 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 21st November 2010, 03:00 PM   #21
adamus is offline adamus  United Kingdom
diyAudio Member
 
Join Date: Apr 2008
dont know until i build it..

It simulates very much like a choke (a big one at that!) but the proof will be in the making and listening.

You can easily improve the PSRR, just stick a v reg infront of it. I am using the salas hv shunt > CCS (soon to be gyrator) > parafeed edcor.
  Reply With Quote
Old 21st November 2010, 03:38 PM   #22
bigwill is offline bigwill  United Kingdom
diyAudio Member
 
Join Date: Dec 2004
Location: UK
Quote:
Originally Posted by Bigun View Post
How does this gyrator design compare with using a choke load ?
Likely to have better bandwidth at either end, lower output impedance if the Mu output is used, better PSRR, adjustable quiescent voltage if needed....
  Reply With Quote
Old 21st November 2010, 07:34 PM   #23
Bigun is offline Bigun  Canada
diyAudio Member
 
Bigun's Avatar
 
Join Date: Jan 2009
Blog Entries: 2
Quote:
Originally Posted by bigwill View Post
Likely to have better bandwidth at either end....
that's entirely possible, unfortunately,I've discovered that 15kHz and above is no longer audible to me
__________________
"The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed." Robert M Pirsig.
  Reply With Quote
Old 21st November 2010, 10:25 PM   #24
athos56 is offline athos56  United States
diyAudio Member
 
athos56's Avatar
 
Join Date: May 2006
Location: Yakima, Washington
Quote:
Originally Posted by Bigun View Post
that's entirely possible, unfortunately,I've discovered that 15kHz and above is no longer audible to me
Yeah, you and me both, darn 357 magnums. I guess we get to save money on output transformers though ...

Athos
  Reply With Quote
Old 22nd November 2010, 02:11 AM   #25
diyAudio Member
 
Michael Koster's Avatar
 
Join Date: Jan 2008
Location: Eureka, CA
Quote:
Originally Posted by bigwill View Post
Wait - This will limit you to 0.7v on the gates due to the forward voltage....

Edit: Ignore me, back to back is not anti-parallel
The DN2540 is rated for +/- 20V gate-source but at normal operating temperatures saturates at about 0Vgs, so a single 15V zener connected with it's anode to the DN2540 gate (as you would a P-channel) works fine for protection.

PS Another option for driving headphone or speaker loads is this balanced current totem pole push-pull circuit using a gyrator. The zener is shown as well as a nice cascode.

Another big difference between the Gyrator/CCS and choke or series feed OPT is the need for higher B+ and consequent dissipation in the active load.
Attached Images
File Type: jpg CascodeGyratorAT.JPG (38.5 KB, 654 views)

Last edited by Michael Koster; 22nd November 2010 at 02:27 AM.
  Reply With Quote
Old 22nd November 2010, 02:50 PM   #26
adamus is offline adamus  United Kingdom
diyAudio Member
 
Join Date: Apr 2008
ok here is a cascode version with dn2540. any improvements welcome.

Click the image to open in full size.
  Reply With Quote
Old 22nd November 2010, 03:37 PM   #27
iko is offline iko  Canada
diyAudio Moderator
 
iko's Avatar
 
Join Date: May 2008
Location: Toronto
Another idea for the gyrator, which I borrowed from Anatoliy. I have built this headphone amp a few days ago and have been listening to it; I think the sound is very good, very dynamic, smooth, no lack of bass, nice full mids. The autoformers I got from a surplus shop for a few dollars. These are the type of line matching transformers used in store ceiling speakers.

I should add that I personally prefer using the mje350, since it's easily available at local shops and can get them easily. I doubt it'd make a difference in sound, when compared to using a dn2540. But that is just a guess.
Attached Images
File Type: jpg amp-hp-6s45pe-autof-2a.jpg (45.8 KB, 560 views)
File Type: jpg amp-hp-6s45pe-autof-2a-gain.jpg (64.3 KB, 550 views)
  Reply With Quote
Old 22nd November 2010, 03:37 PM   #28
Sheldon is offline Sheldon  United States
diyAudio Member
 
Join Date: Dec 2003
Location: San Diego
Looks fine to me. Since your gate is driven by the plate supply, I think protection diodes aren't necessary. A short from output to ground would be a problem, but that should be easy to avoid.

BTW, with the cascode, a low voltage JFET is an option for the bottom device.

Sheldon
  Reply With Quote
Old 22nd November 2010, 03:39 PM   #29
adamus is offline adamus  United Kingdom
diyAudio Member
 
Join Date: Apr 2008
Quote:
Originally Posted by ikoflexer View Post
Another idea for the gyrator, which I borrowed from Anatoliy. I have built this headphone amp a few days ago and have been listening to it; I think the sound is very good, very dynamic, smooth, no lack of bass, nice full mids. The autoformers I got from a surplus shop for a few dollars. These are the type of line matching transformers used in store ceiling speakers.
I am just this minute drawing up a similar version (but with much smaller cap and a pnp cascode). I'll sim it to make sure no boo boos.
  Reply With Quote
Old 22nd November 2010, 03:42 PM   #30
iko is offline iko  Canada
diyAudio Moderator
 
iko's Avatar
 
Join Date: May 2008
Location: Toronto
Quote:
Originally Posted by Sheldon View Post
BTW, with the cascode, a low voltage JFET is an option for the bottom device.
Sheldon
Indeed, I have made an excellent CCS using the dn2540 in the upper position, and a 2sk170 in the lower position. For higher current one can either parallel 2sk170s, or use a higher Idss jfet.
  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
New PNP HV tranny for anode CCS richwalters Tubes / Valves 12 8th November 2010 10:35 AM
Rod Coleman CCS/gyrator help zigzagflux Tubes / Valves 14 6th March 2010 11:40 PM
CCS or V.REG for OP anode pointy Tubes / Valves 0 20th January 2010 11:25 AM
chocke anode load, please explain me.. inertial Tubes / Valves 7 20th February 2009 11:47 AM
LL1673 as anode load? walkwalk Tubes / Valves 1 13th July 2005 02:04 PM


New To Site? Need Help?

All times are GMT. The time now is 11:41 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