Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Pass Labs This forum is dedicated to Pass Labs discussion.

Building a Pearl 2
Building a Pearl 2
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 September 2018, 03:18 PM   #1061
Eric is offline Eric  United States
diyAudio Member
 
Eric's Avatar
 
Join Date: Nov 2000
Location: Central PA, USA
Building a Pearl 2
I was waiting for that one, Jack
__________________
My DIY Basement Theater, Aleph-X Amps, Avro Open Baffle Speakers, LDR based BA-3 pre, Pearl II, highly modded Technics SL-1200, F4, M2, a40, several ACAs, FHXL, Tang Band 1772 bass-reflex
  Reply With Quote
Old 21st September 2018, 07:38 PM   #1062
laverda is offline laverda  United Kingdom
diyAudio Member
 
Join Date: Nov 2004
Location: Hampshire
They don't measure very well....
__________________
Every Day In Every Way I Make It Pay
  Reply With Quote
Old 10th October 2018, 10:52 PM   #1063
metalman is offline metalman  Canada
diyAudio Member
 
metalman's Avatar
 
Join Date: Jun 2003
Location: Victoria, BC, Canada
Finally had a chance to test out my Pearl 2 Build ... Lady Luck was with me and she played perfectly straight out of the gate . Many of you will laugh at me, but I guess I need to go buy a good turntable now (borrowed a friends for testing purposes ).
I built the gain boards stock except for adding a 220uF series capacitor to R14 to stabilize DC offset. The offset slowly and slightly wanders, but stays less than +/-1mV.
For the power supply I went dual mono after the transformer (24V secondaries), which was a minor mistake because I had originally designed around one supply for both channels, and after splitting it the voltage rails crept up to 35V leaving no safety margin for the caps on the gain boards in front of the regulators. Used CLC with 10,000uF caps and 6.8mH inductors that also had 14.7 ohm DCR (measured). I'm really happy with how the PS turned out, as it has ~0.2mV ripple, and will really keep RF down as well.
I was really concerned about hum from grounding and from the PS radiated noise, so I made my power umbilical 10ft long just to be safe. I definitely have avoided hum, its dead quiet except for a slight Mosfet hiss if I crank the volume up and put my ear right next to the speaker. For giggles I stacked the two chassis just to see what happens, and it stayed just as silent. Thank you to 6L6 and everyone else on their grounding layout advice.
The sound was excellent straight out of the gate with an entry level ProJect turntable and an Ortofon OM-5 cartridge. I'm curious to see what some burn in time will produce, and how it sounds with the Dual 505-3 that I inherited from my Dad but now need to pick up from my dear ol' Mum. My suspicion is that I will find myself bit by the upgrade bug wrt to the turntable.
Attached Images
File Type: jpg Pearl Both Front.jpg (812.2 KB, 234 views)
File Type: jpg Pearl Both Back.jpg (819.6 KB, 224 views)
File Type: jpg Pearl Both Inside.jpg (821.3 KB, 227 views)
File Type: jpg Pearl Gain Overview.jpg (782.6 KB, 230 views)
File Type: jpg Pearl Gain Board.jpg (941.0 KB, 169 views)
File Type: jpg Pearl PS Overview.jpg (738.7 KB, 86 views)
File Type: jpg Pearl PS Board.jpg (862.9 KB, 82 views)
__________________
Darn career gets in the way of my audio addiction!

Last edited by metalman; 10th October 2018 at 11:03 PM.
  Reply With Quote
Old 10th October 2018, 11:29 PM   #1064
6L6 is offline 6L6  United States
diyAudio Moderator
 
6L6's Avatar
 
Join Date: Oct 2010
Location: Denver, Colorado
Building a Pearl 2
Absolutely fantastic !!!

My most sincere congratulations on a successful build.

As for turntable, keep your eye out for a good SP-10mk2. Might as well just buy your last table first...
  Reply With Quote
Old 14th October 2018, 06:40 PM   #1065
McQuaide is offline McQuaide  United States
diyAudio Member
 
Join Date: Jan 2011
Location: Southeastern Pennsylvania
Default New Pearl 2 - too sensitive

Hi all, just finished my second Pearl 2. Voltages check out OK, the LEDs light up, offset is set near zero. Both boards are super-sensitive and loud, especially with MM cartridges. They distort on loud passages but sound fantastic otherwise. With my O2 headphone amp I can't turn the volume past 7 or 8 o'clock.


R14 checks out at 1K. Any ideas what's going on?
  Reply With Quote
Old 14th October 2018, 06:44 PM   #1066
vinylkid58 is offline vinylkid58  Canada
diyAudio Member
 
vinylkid58's Avatar
 
Join Date: May 2005
Location: Victoria, B.C.
Quote:
Originally Posted by metalman View Post
Finally had a chance to test out my Pearl 2 Build ... Lady Luck was with me and she played perfectly straight out of the gate .
Congrats, that's a very nice looking build. Love to hear it sometime.

jeff
  Reply With Quote
Old 14th October 2018, 06:50 PM   #1067
KatieandDad is offline KatieandDad  United Kingdom
diyAudio Member
 
KatieandDad's Avatar
 
Join Date: Nov 2011
Location: UK
The Pearl 2 is designed to be used with low output MC cartridges, you will be severely overloading it with a high output MM cartridge. IIRC the Pearl 1 was designed for MM cartridges.

It would be counter advantage to have the extra gain of the Pearl 2 to then attenuate it as the Pearl 2 by its nature will be noisier than a Pearl 1.

Last edited by KatieandDad; 14th October 2018 at 07:06 PM.
  Reply With Quote
Old 14th October 2018, 07:05 PM   #1068
McQuaide is offline McQuaide  United States
diyAudio Member
 
Join Date: Jan 2011
Location: Southeastern Pennsylvania
Quote:
Originally Posted by KatieandDad View Post
The Pearl 2 is designed to be used with low output MC cartridges, you will be severely overloading it with a high output MM cartridge. IIRC the Pearl 1 was designed for MM cartridges.

The Pearl 2 default is 55db of gain for MM carts, reducing R14 to 300 ohm increases it to 65db for MC carts. I've been using a Pearl 2 for a long time with both.
  Reply With Quote
Old 14th October 2018, 07:08 PM   #1069
KatieandDad is offline KatieandDad  United Kingdom
diyAudio Member
 
KatieandDad's Avatar
 
Join Date: Nov 2011
Location: UK
I use mine with a low output Linn Aktiv and it performs perfectly. My point is that the OP is clearly over driving his.
  Reply With Quote
Old 14th October 2018, 07:23 PM   #1070
McQuaide is offline McQuaide  United States
diyAudio Member
 
Join Date: Jan 2011
Location: Southeastern Pennsylvania
Quote:
Originally Posted by KatieandDad View Post
I use mine with a low output Linn Aktiv and it performs perfectly. My point is that the OP is clearly over driving his.

I'm trying to figure out how it's being overdriven by a 4mv cartridge - this is my second Pearl 2, and the first one has no issues with the same cart. There is something going on with it.
  Reply With Quote

Reply


Building a Pearl 2Hide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
RIAA caps for Pearl and Pearl 2 AudioLapDance Pass Labs 7 22nd May 2015 07:19 PM
pearl HELP! d to the g Pass Labs 24 31st May 2007 01:56 PM
Pearl need help dzkh63 Pass Labs 1 26th September 2006 03:16 PM
Anyone building a pearl phono soon? mattjk Pass Labs 8 24th March 2005 12:20 AM
The Pearl-X Vince Maida Pass Labs 12 28th July 2002 07:28 AM


New To Site? Need Help?

All times are GMT. The time now is 03:41 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki