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 10th October 2011, 07:13 PM   #1
diyAudio Member
 
Join Date: Sep 2009
Location: Dortmund
Unhappy B! finished - HELP needed...

Hi everyone...

I've just finished my new B1. Schematic taken from Passlabs. But there is only dead silence at the outputs.

Here is the schematic:
Click the image to open in full size.

Here is my layout:
Click the image to open in full size.

I can't find any mistake... So please anyone help me with this problem.
  Reply With Quote
Old 10th October 2011, 07:20 PM   #2
diyAudio Member
 
Join Date: Jun 2007
The schematics are not showing up.

None the less, tell us what is working.

For instance is there a voltage after the smoothing caps? What does a voltmeter or scope show at the outputs, when a signal is on or off at the input etc....?
  Reply With Quote
Old 10th October 2011, 07:43 PM   #3
6L6 is online now 6L6  United States
diyAudio Member
 
6L6's Avatar
 
Join Date: Oct 2010
Location: Denver, Colorado
Your images --

Click the image to open in full size.

Click the image to open in full size.


If you can take any voltage measurements anywhere, that will help.

Also, could you take some photos of it and post them here?

For reference, the Original B1 schematic -
Click the image to open in full size.
__________________
Illustrated Build Guides - Pass F4 - Pass B1 - Pass F5 - Pearl 2 - O2 HPA - Hagerman Bugle 2 - Pass Aleph J - Me at BA '13

Last edited by 6L6; 10th October 2011 at 07:49 PM.
  Reply With Quote
Old 10th October 2011, 07:53 PM   #4
diyAudio Member
 
Join Date: Sep 2009
Location: Dortmund
Oh... I took some voltage measurements. VCC behind the smoothingcaps is 18,68V. I used 2SK170 as mentionend in the Passlabs article. No matching. I only want to see if this gem is working. But it won't make any noise.

Where are positions to measure which would be interesting?

I can take some pictures of the inside tomorrow when i'm back from work.
  Reply With Quote
Old 10th October 2011, 08:12 PM   #5
diyAudio Member
 
Join Date: Sep 2009
Location: Dortmund
Are you now able to open the pictures?
Attached Images
File Type: jpg 20111010_220157.jpg (430.4 KB, 129 views)
File Type: jpg 20111010_220211.jpg (436.7 KB, 123 views)
  Reply With Quote
Old 10th October 2011, 08:24 PM   #6
6L6 is online now 6L6  United States
diyAudio Member
 
6L6's Avatar
 
Join Date: Oct 2010
Location: Denver, Colorado
Yes, the photos of the preamp are visible.

Looking at your layout it seems that you have the signal going to the source of the 'top' transistor. I could be wrong, it's hard to see.

Check your transistor layout.

Here is the datasheet for the 2sk170

http://www.datasheetcatalog.org/data...shiba/1027.pdf
__________________
Illustrated Build Guides - Pass F4 - Pass B1 - Pass F5 - Pearl 2 - O2 HPA - Hagerman Bugle 2 - Pass Aleph J - Me at BA '13

Last edited by 6L6; 10th October 2011 at 08:28 PM.
  Reply With Quote
Old 10th October 2011, 08:44 PM   #7
generg is offline generg  Germany
diyAudio Member
 
generg's Avatar
 
Join Date: Jul 2009
Location: Near Frankfurt
Hi xandrell,

Is far as I can see, you used the pin layout of the IRF 610 or IRF 9610 were the gate is on the left side looking on the front of semiconductor, where the words are, but Sk170 has the gate in the middle and the drain and source outside.

So check your j-FETs and solder them new twisting the legs!


http://www.datasheetcatalog.org/data...shiba/1027.pdf

6L6 is right!
__________________
and the First Wtt is......a really First Class PSS Idea

Last edited by generg; 10th October 2011 at 08:47 PM.
  Reply With Quote
Old 11th October 2011, 03:16 AM   #8
diyAudio Member
 
Join Date: Sep 2009
Location: Dortmund
Yes. You both are right. Had this idea while sleeping ;-) I will try to fix that. So pin1 goes to slot2 and vice versa? 3 stays at slot 3.
Or is this also wrong?
  Reply With Quote
Old 11th October 2011, 04:42 AM   #9
6L6 is online now 6L6  United States
diyAudio Member
 
6L6's Avatar
 
Join Date: Oct 2010
Location: Denver, Colorado
If the board was designed for IRF610, then yes, you need to get a bit of teflon tubing and insulate a lead or two and cross the legs.

For reference, IRF610 datasheet -- http://www.hebertech.com/datasheet/vishay/irf610.html
__________________
Illustrated Build Guides - Pass F4 - Pass B1 - Pass F5 - Pearl 2 - O2 HPA - Hagerman Bugle 2 - Pass Aleph J - Me at BA '13
  Reply With Quote
Old 11th October 2011, 05:36 AM   #10
generg is offline generg  Germany
diyAudio Member
 
generg's Avatar
 
Join Date: Jul 2009
Location: Near Frankfurt
Pin 3 to slot 3, isn't then the drain of J-Fet connected to the source place of IRF holes?

In German im zweiten Pinbelegungsbild sieht man den Transistor von unten und im ersten von der Schriftseite.

It is so easy to get confused by the pin pictures, reflect 5 times please!


At least for me!

Nevertheless you did a fine work!
__________________
and the First Wtt is......a really First Class PSS Idea

Last edited by generg; 11th October 2011 at 05:40 AM.
  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
Help needed ! Inter M R300 schematics needed ! alexclaire Solid State 30 9th September 2009 06:14 AM
LT1964-adj Help Needed or Part Needed lgreen Parts 2 29th June 2007 02:50 PM
finished !!! tenderland Tubes / Valves 3 6th August 2006 01:59 AM
Finished sub perpetual Subwoofers 11 19th June 2005 01:42 AM


New To Site? Need Help?

All times are GMT. The time now is 01:06 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