The F5X Preamp - Page 3 - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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 11th December 2012, 06:43 PM   #21
gl is offline gl  United States
diyAudio Member
 
Join Date: Dec 2003
Location: Sierra Foothills - California
Hi Patrick,

I really like your circuit. It definitely does have a UGS look to it.

I don't see why you included R51 and R52. If it was an X type circuit then I would understand.

Graeme
  Reply With Quote
Old 11th December 2012, 07:06 PM   #22
diyAudio Member
 
wuffwaff's Avatar
 
Join Date: Aug 2001
Location: Ingolstadt Germany
Hi Patrick,

that sounds good. If you need a beta tester..........

Wiliam
__________________
een ooievaar is geen konijn want zijn oren zijn te klein!
  Reply With Quote
Old 11th December 2012, 07:30 PM   #23
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
R51, 52 are optional.

William, we'll get in touch when the time comes.


Patrick
__________________
xen-audio.com
  Reply With Quote
Old 11th December 2012, 07:48 PM   #24
gl is offline gl  United States
diyAudio Member
 
Join Date: Dec 2003
Location: Sierra Foothills - California
Is there a reason why I would want to include them as an option?

Graeme
  Reply With Quote
Old 11th December 2012, 07:51 PM   #25
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
No.

But there is also no reason why anyone would need a Porsche.
And many have one.




Patrick
__________________
xen-audio.com
  Reply With Quote
Old 11th December 2012, 09:05 PM   #26
gl is offline gl  United States
diyAudio Member
 
Join Date: Dec 2003
Location: Sierra Foothills - California
Thank you for the advice on cars. However, I don't think my wife would let me buy a Porsche.

By the way, in your post you forgot to give the technical reason why R51 and R52 would be 'optionally' included in your circuit?

Thank you.

Graeme

Last edited by gl; 11th December 2012 at 09:28 PM.
  Reply With Quote
Old 11th December 2012, 09:27 PM   #27
diyAudio Member
 
apassgear's Avatar
 
Join Date: Nov 2002
Location: Viña del Mar, Torreon
Might be wrong, but looks like a JC topology?
  Reply With Quote
Old 11th December 2012, 10:04 PM   #28
gl is offline gl  United States
diyAudio Member
 
Join Date: Dec 2003
Location: Sierra Foothills - California
Hi Patrick,

After re-reading your last post I see that you did answer my question regarding R51 and R52. Thank you.

Graeme
  Reply With Quote
Old 12th December 2012, 04:41 AM   #29
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
> Might be wrong, but looks like a JC topology?

If you read the article carefully, I immediately acknowledged the similarity to the JC-80 and gave the credit to John.
We did worked out the circuit ourselves before John published the JC80 schematics.
So like Nelson has to refer the F5X topology to ProFET, we do the same to the JC-80.

But the devils are in the details. And they will follow.

To answer your question directly, I personally like to include a ground return path of the outputs.
Especially when the input is a floated X or a H, like in the schematics in the article.
You can argue it is not necessary. Straightly speaking it is not.
But this is what I like. Hence it is optional.




Patrick
__________________
xen-audio.com
  Reply With Quote
Old 12th December 2012, 05:26 AM   #30
Blues is offline Blues  United States
Lightning In A Bottle
diyAudio Member
 
Blues's Avatar
 
Join Date: Sep 2003
Location: The Milky Way
I would venture to guess it's from PMA's interpretation of JC's Blowtorch (official circuit not published yet) embellished with jfet cascodes and F5 feedback to set the voltage gain.

9/23/2009:
http://www.diyaudio.com/forums/analo...ml#post1930881
  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
F5X -- the EUVL Approach EUVL Pass Labs 863 19th September 2014 11:31 AM
2 x EUVL F5X Designed Case toufu Swap Meet 4 3rd October 2012 06:21 PM
F5X Case Horio Pass Labs 34 14th August 2012 03:05 AM
F5X Transformers mravinsky Group Buys 122 16th February 2012 07:18 PM
F5X Transformers mravinsky Group Buys 1 10th January 2012 05:40 PM


New To Site? Need Help?

All times are GMT. The time now is 10:27 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