Preamp ideas for F5 - Page 27 - 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 3rd August 2012, 12:39 AM   #261
flg is offline flg  United States
diyAudio Member
 
flg's Avatar
 
Join Date: Jul 2005
Location: North East
Yes, Certainly. I beleive the article actually does not connect the output to the output stage does it?
__________________
"It was the perfect high end audio product: Exotic, inefficient, expensive, unavailable, and toxic." N.P.
  Reply With Quote
Old 3rd August 2012, 10:11 AM   #262
diyAudio Member
 
Join Date: Jan 2012
Location: Pennsylvania
Blog Entries: 1
Quote:
Originally Posted by flg View Post
Yes, Certainly. I beleive the article actually does not connect the output to the output stage does it?
Hello Mr. dB and flg. The schematic of the input board for BA3 shows it to be a Transconductance Amplifier [TCA]. Its output has opposed drains and it is void of loop feedback. diyAudio is a fertile ground to share new ideas, and to experiment with the proposed devices. Conventional wisdom has its place. But nothing [unless unsafe] should be cast in stone. The thinking that this is how it was, is, and will always be done is unhealthy and a counter productive approach for this hobby. For example; who would have guessed that Mr. Pass will ever use an interstage transformer in a power amp like F6? He never used this approach before; knowing the ills attendant to a transformer..

I continue to enrich my two topics in Headphone Systems to be commensurate with my philosophy above. Best regards.
  Reply With Quote
Old 3rd August 2012, 10:34 AM   #263
neoinc is offline neoinc  Singapore
diyAudio Member
 
neoinc's Avatar
 
Join Date: Dec 2008
Quote:
Originally Posted by Mr. dB View Post
Pardon me for being dense, but do I understand correctly that some people are suggesting the BA3 input board for a line-stage preamp?
I used it as a preamp for my F5, and it is sweet. The soundstage is very wide.
Personally i felt the magic isnt there when i put it in a F4.

Last edited by neoinc; 3rd August 2012 at 10:36 AM.
  Reply With Quote
Old 3rd August 2012, 10:39 AM   #264
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
neoinc,
Did you drop the input Jfets on the F4? THis would make it a true BA3. Intersting that you like it in front of F5. Might have to try that. Seems like you are hearing the F5 and not the BA3 FE.
__________________
...Shape the sound , Man!
  Reply With Quote
Old 3rd August 2012, 10:48 AM   #265
neoinc is offline neoinc  Singapore
diyAudio Member
 
neoinc's Avatar
 
Join Date: Dec 2008
Quote:
Originally Posted by buzzforb View Post
neoinc,
Did you drop the input Jfets on the F4? THis would make it a true BA3. Intersting that you like it in front of F5. Might have to try that. Seems like you are hearing the F5 and not the BA3 FE.
The jfets were taken out for F4. However i do put a B1 infront of BA3 for volume control. Imho, F5 need good pre-amp, a B1 is not good enough to enjoy the F5.
  Reply With Quote
Old 3rd August 2012, 10:57 AM   #266
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
I did not like the B1 in front of the BA3. MY favorite was Salas 6V6 in front of BA3. I do in fact like the DCB1 in front of the F5T. Good synergy. Throw volume pot on front of BA3. No need for B1.
__________________
...Shape the sound , Man!
  Reply With Quote
Old 3rd August 2012, 11:01 AM   #267
flg is offline flg  United States
diyAudio Member
 
flg's Avatar
 
Join Date: Jul 2005
Location: North East
Quote:
Originally Posted by Antoinel View Post
...The schematic of the input board for BA3 shows it to be a Transconductance Amplifier [TCA]. Its output has opposed drains and it is void of loop feedback...
Yes, this would be true but, by saying that, you are indicating, like a current source, it has high output impeadance. It does not. The output is loaded heavily effectively changing it to a voltage source.
__________________
"It was the perfect high end audio product: Exotic, inefficient, expensive, unavailable, and toxic." N.P.
  Reply With Quote
Old 3rd August 2012, 11:02 AM   #268
neoinc is offline neoinc  Singapore
diyAudio Member
 
neoinc's Avatar
 
Join Date: Dec 2008
Thanks buzzforb, i am thinking of putting a volume knob too but should i put it infront or after the ba3? Is 10k pot good enough?
  Reply With Quote
Old 3rd August 2012, 11:05 AM   #269
diyAudio Member
 
Join Date: Jan 2012
Location: Pennsylvania
Blog Entries: 1
Quote:
Originally Posted by neoinc View Post
I used it as a preamp for my F5, and it is sweet. The soundstage is very wide.
Personally i felt the magic isnt there when i put it in a F4.
Hello buzzforb and neoinc. My philosophy for diyAudio is like yours. Experiment, experiment etc. Best regards.
  Reply With Quote
Old 3rd August 2012, 11:11 AM   #270
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
Quote:
Originally Posted by neoinc View Post
Thanks buzzforb, i am thinking of putting a volume knob too but should i put it infront or after the ba3? Is 10k pot good enough?
In front of Ba3, IMO. 10k is good, as you have Ciss of input Jfets and Mr Miller to deal with.
__________________
...Shape the sound , Man!
  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
Discrete Op Amp Ideas for a Preamp analog_guy Solid State 16 16th June 2007 04:18 AM
Preamp signal wiring ideas ? gurevise Tubes / Valves 7 30th January 2007 07:19 PM
Ideas for preamp box design paulspencer Analog Line Level 5 26th August 2006 06:46 PM
Ideas for using one ECL82 in a preamp Tyimo Tubes / Valves 17 6th May 2006 05:35 AM


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