Pearl Two - Page 5 - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Thread Tools Search this Thread
Old 28th December 2009, 08:41 PM   #41
acaudio is offline acaudio  Germany
diyAudio Member
Join Date: Sep 2004
Location: Germany
The circuit seems to be very similar with simplified Aleph ono.
Best regards, A.
  Reply With Quote
Old 28th December 2009, 09:20 PM   #42
mlloyd1 is offline mlloyd1  United States
diyAudio Member
mlloyd1's Avatar
Join Date: Feb 2001
Location: Northern Iliinois
after reading these groups for so many years, the following response wouldn't leave my head until i typed it.

apologies to nelson for badly butchering an earlier comment of his that i especially like ...

"we don't need no values; we are fearless preamp builders.
but we have spare jfets, just in case ..."

btw, thanks wayne!

Originally Posted by wayne View Post
Here is the Pearl Two schematic. You will have to wait for values.
  Reply With Quote
Old 28th December 2009, 11:36 PM   #43
diyAudio Member
Benedetto's Avatar
Join Date: Nov 2007
Location: Knifetown-Germoney
u r such a teaser.

Happy new year
  Reply With Quote
Old 29th December 2009, 04:55 AM   #44
ra7 is offline ra7  United States
diyAudio Member
Join Date: Feb 2009
the first stage is similar to the pearl. second stage looks interesting. can't wait, wayne!
  Reply With Quote
Old 29th December 2009, 08:20 AM   #45
diyAudio Member
Join Date: Dec 2000
Location: Germany
Second stage is still a discrete OP Amp.

Clever mix of J-Fet, Mos-Fet as amplifier and Led/BJT as current sources.

  Reply With Quote
Old 29th December 2009, 05:45 PM   #46
Merijn is offline Merijn  Netherlands
diyAudio Member
Join Date: May 2002
Location: Arnhem, The Netherlands
This is sooo nice! Can't wait to order
===I prefer coffee for Mental Stability===
  Reply With Quote
Old 29th December 2009, 07:29 PM   #47
GuidoR is offline GuidoR  Italy
diyAudio Member
GuidoR's Avatar
Join Date: Jun 2006
Location: Bergamo
Originally Posted by wayne View Post
Here is the Pearl Two schematic. You will have to wait for values.
...or fully "open" the screen of your laptop and look at the schematic from a very open angle...and the values magically will appear...

sorry Wayne, it's

And many, many thanks, I can't wait...

Only a comment: 7824/7924: there's room for improvement, I think

  Reply With Quote
Old 29th December 2009, 09:25 PM   #48
MRupp is offline MRupp  Germany
diyAudio Member
MRupp's Avatar
Join Date: Dec 2003
Location: Frankfurt area
Only a comment: 7824/7924: there's room for improvement, I think
Just a suggestion - I was working on a VERY simple shunt regulator that is inspired by elements from previous "passdiy" designs, so it may actually fit here. The error amp is simply a differential pair, same as in the original Pearl series regulator, followed by two BJTs for the shunt element in place of the (series) FET in the original. The current source is basically a ZEN current source.

The circuit is very simple and you can off course get "better" performance (lower impedance) by means of higher amplification factor/feedback, through a more complex error amp (IC opamp or other) - there are numerous examples out there. And you can also go on for months toying with all kinds of variations but you may just be beating the subject to death (I spent a substantial amount of time on variations of the ctoole shuntreg and will not do this again).

At least my simulations look very promising and show flat load regulation over a very broad frequency range. I am quite confident that the circuit works well "as is" though I may be leaning myself out of the window a little bit by not having prototyped it. I am in the process of building such a prototype on a PCB, but that may take some time and you may not like my PCB version anyway, so if you are interested I strongly suggest not to wait and try it for yourself to see how it performs.
Attached Images
File Type: jpg Simple-shuntreg.jpg (35.8 KB, 2697 views)
Martin Rupp
  Reply With Quote
Old 29th December 2009, 11:44 PM   #49
hates ground loops
diyAudio Member
Rodeodave's Avatar
Join Date: Dec 2004
Location: in the alps
Blog Entries: 1
Originally Posted by GuidoR View Post
...and the values magically will appear...
omfglol, this reminds me of U.S. military security defeated by copy and paste - CNET News
Gravity - Making the G since 13.7 billion B.C.
  Reply With Quote
Old 30th December 2009, 12:02 AM   #50
wayne is offline wayne  United States
In the hills
diyAudio Member
Join Date: Jan 2002
Location: Northern California
Default Pearl PC Boards

The boards will be arriving after we return from CES in Las Vegas.
They are sized like the Pearl and will drop in. We will sell with matched fets.

A power supply board will follow if anybody wants one. ???
  Reply With Quote


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
Another diy-pearl... lykkedk Pass Labs 18 15th June 2007 04:44 PM
ono or pearl PCB's mantisory Pass Labs 1 28th September 2006 11:12 PM
Pearl need help dzkh63 Pass Labs 1 26th September 2006 03:16 PM
WTB: Pearl PCB aire Pass Labs 1 26th February 2006 10:51 AM

New To Site? Need Help?

All times are GMT. The time now is 01:37 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2