Different values of C7 (CE) in Alephs - 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 4th February 2003, 03:28 PM   #1
Josep is offline Josep  Europe
diyAudio Member
 
Join Date: Jan 2002
Location: Europe
Smile Different values of C7 (CE) in Alephs

Hello all

I am making an Aleph 30 with Kristijan PCBs for Aleph 5.
It is easy to adapt but my doubt is about C7.
The only difference in my A30 is that C7 is from the collector to emitter instead collector to base in original A30.
BrianGT ask to Mr. Pass about similar problem and he say :
"The value of the npn compensation cap pretty much depends on the placment. .001 for CB or .01 for CE."
I see different schematics with 0.047 or 0.01 for collector to emitter placement. What it is the correct value in this case?
Thank you

Josep

Note : Sorry for my bad English.
  Reply With Quote
Old 4th February 2003, 03:39 PM   #2
uli is offline uli  Austria
diyAudio Member
 
Join Date: Dec 2002
Location: Vienna, Austria
Default try and error

hi,
this cap is either nfb (CB) or output to gnd (CE).
It forms a lo pass with R18 in the CE config.
in CB it forms a fb loop thus "slowing down" the npn
to avoid oszillation.
I would put either .001 in CB or .047 in CE.
Try it!
Uli
__________________

'Jazz is not dead, it just smells funny' F.Zappa
  Reply With Quote
Old 4th February 2003, 03:39 PM   #3
diyAudio Member
 
Join Date: Dec 2001
Location: Philadelphia
I would trust Mr. Pass!
__________________
Vince Harris
  Reply With Quote
Old 4th February 2003, 06:28 PM   #4
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
Lots of times it works fine without a cap, but not
always.
  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
Best Alephs for a bi-amp configuration Sony Pass Labs 2 12th January 2005 07:20 PM
Any old alephs dhole Pass Labs 1 10th December 2004 08:33 PM
Audioquest stuff between Alephs tortello Pass Labs 2 14th January 2003 07:47 AM
what are the differences between the different alephs? Bricolo Pass Labs 19 31st December 2002 05:48 AM
Parralleled Alephs audionut Pass Labs 6 22nd November 2002 05:26 AM


New To Site? Need Help?

All times are GMT. The time now is 05:38 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