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.

Aleph J illustrated build guide
Aleph J illustrated build guide
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 10th September 2019, 07:32 PM   #3871
Zen Mod is offline Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Aleph J illustrated build guide
everything OK

dc offset?
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 10th September 2019, 08:38 PM   #3872
ontool is offline ontool
diyAudio Member
 
Join Date: Sep 2019
Quote:
Originally Posted by Zen Mod View Post
dc offset?
Yes, on the resistors, the 0.47th output transistor at a temperature of ~ 70 * C, a voltage of 0.4 volts. That sounds very good.
Thanks to Mr. Pass , simplicity is the key to reliability and quality
  Reply With Quote
Old 13th September 2019, 09:09 AM   #3873
ontool is offline ontool
diyAudio Member
 
Join Date: Sep 2019
Quote:
Originally Posted by Zen Mod View Post
everything OK
The bias voltage and the quiescent current on both channels are the same, but the gain on one channel is slightly less, the question is how to combine them to get the same signal level?
Attached Files
File Type: mp4 IMG_0173.mp4 (1.52 MB, 13 views)
  Reply With Quote
Old 13th September 2019, 09:41 AM   #3874
mbrennwa is offline mbrennwa  Switzerland
diyAudio Member
 
mbrennwa's Avatar
 
Join Date: Mar 2005
Location: Zurich, Switzerland
Aleph J illustrated build guide
Quote:
Originally Posted by ontool View Post
The bias voltage and the quiescent current on both channels are the same, but the gain on one channel is slightly less, the question is how to combine them to get the same signal level?
As far as I can tell from your video, the DVM was set to read DC voltage across the speaker terminals. How is this going to tell you anything about the gain (AC!) of your amp?

You'd need to hook up your amp such that both channels get the same input (I'd suggest a 100 mV sine at 100 Hz or so) and then read the AC voltages across the speaker terminals of both channels in order to learn something about the gain balance of the two channels.
__________________
------
Group buy for augerpro waveguides for Scan Speak tweeters -- elliptical version -- circular version
  Reply With Quote
Old 13th September 2019, 09:53 AM   #3875
ontool is offline ontool
diyAudio Member
 
Join Date: Sep 2019
Quote:
Originally Posted by mbrennwa View Post
As far as I can tell from your video, the DVM was set to read DC voltage across the speaker terminals.
The video shows the voltage offset at the output of the amplifier.
The difference in gain on each channel is audible even without measurements. The question was what is regulated, how can I level both channels, ok?
  Reply With Quote
Old 13th September 2019, 03:51 PM   #3876
Dennis Hui is offline Dennis Hui  Canada
Hoopy Frood
diyAudio Member
 
Join Date: Aug 2002
Location: Toronto, Canada
Aleph J illustrated build guide
Hi Roo2,

Any news on your AJ build?

Dennis
__________________
We are fearless amplifier builders. A little heat doesn't scare us at all.
- NP 2002
  Reply With Quote
Old 18th September 2019, 03:12 PM   #3877
Myint67 is offline Myint67  Singapore
diyAudio Member
 
Join Date: Dec 2013
Location: Singapore
Default One Chanel no sound

Hello my aleph J one Chanel is no sound .
Basic is .47 MV and DC cannot set (-0000.00)
Pls tell me what can I do now ?

Best regards
Myint
  Reply With Quote
Old 18th September 2019, 03:26 PM   #3878
Zen Mod is offline Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Aleph J illustrated build guide
Quote:
Originally Posted by ontool View Post
The video shows the voltage offset at the output of the amplifier.
The difference in gain on each channel is audible even without measurements. The question was what is regulated, how can I level both channels, ok?
if you have genuine JFets in input ( BL range) , if all resistors are the same ,there is no reason that channels are having different gain

check all resistors , if there is no doubt in JFets

Quote:
Originally Posted by Myint67 View Post
Hello my aleph J one Chanel is no sound .
Basic is .47 MV and DC cannot set (-0000.00)
Pls tell me what can I do now ?

Best regards
Myint

pics
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 18th September 2019, 04:17 PM   #3879
ItsAllInMyHead is online now ItsAllInMyHead  United States
diyAudio Member
 
Join Date: Mar 2019
Location: The great state of Minnesoooota.
I got the Aleph J updated to dual-mono. Thanks to everyone for the advice, particularly ZM and @TungstenAudio. ZM, I'll get the fuses put into the SissySIT next.

It's getting back up to operating temp in the main system, but everything checked out wonderfully with the test rig.

Before and After...
Attached Images
File Type: jpg IMG_1530.jpg (758.3 KB, 219 views)
File Type: jpg IMG_1531.jpg (808.3 KB, 383 views)
  Reply With Quote
Old 18th September 2019, 04:35 PM   #3880
TungstenAudio is offline TungstenAudio  United States
diyAudio Member
 
Join Date: Jan 2014
Location: Kenmore, WA
Nicely done! Very tidy
  Reply With Quote

Reply


Aleph J illustrated build guideHide 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
An illustrated guide to building an F5 6L6 Pass Labs 1214 12th September 2019 08:23 PM
MyRefC build guide AndrewT Chip Amps 1119 29th July 2016 10:30 PM
An illustrated guide for Aleph 60 builders PKI Pass Labs 58 12th October 2013 07:13 PM
Aleph J Stuffing guide ? thor61 Pass Labs 2 4th September 2011 08:02 PM
My first step by step LM3886 illustrated build kgb_m3 Chip Amps 19 17th February 2010 04:46 PM


New To Site? Need Help?

All times are GMT. The time now is 12:48 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki