diyAB Amp The "Honey Badger" build thread - Page 71 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 9th November 2013, 07:20 PM   #701
PJN is offline PJN  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Pa, USA
Hi Guys,

I finally got some time to work on my boards, still no luck. I had to change out R8,9,15,16, & 26. Changed them all to 100R as spec'd in BOM, in the original order Digikey set 100K instead of 100R and I hadn't double checked. I triple checked all of the transistors they are all as called for in the BOM. When power is applied I get 126 VDC across the 10R resistor on F1, and 0.014VDC across the 10R on F2. When I junped the bases of Q14 and Q15 to the end of R43 closest to the bottom of the board, nothing changed. One thing though I checked across each of the legs of the larger transistors for continuity all had now with the excepting of Q13. On Q13 I get 1.16K between the base and the end pin, but no continuity between the base and the middle pin, I don't know enough to know itf this means something.

At this point I'm stumped, I'm beginning to wonder if I got a bunch of bum transistors, or something. Any guidance would be appreciated. I've attached some close up pics.

Thanks

PJN
Attached Images
File Type: jpg Frontside 1.jpg (292.2 KB, 510 views)
File Type: jpg Frontside 2.jpg (305.5 KB, 495 views)
File Type: jpg Backside 1.jpg (330.8 KB, 470 views)
File Type: jpg Backside 2.jpg (350.4 KB, 459 views)
  Reply With Quote
Old 9th November 2013, 07:52 PM   #702
diyAudio Member
 
ostripper's Avatar
 
Join Date: May 2008
Location: Albany , NY (smallbany)
Your VAS heatsink looks like 1/8" stock. That might short out Q11/12.
I just have roof flashing (thin) for this HS and the devices are ideal.

If your meter has the "diode"setting test every device B-E and B-C. On both
of my DMM's ....
Big diodes = .530
small diodes -=.670
small transistors = .7xx (.732 etc.)
Large transistors = .6xx

Remember - red lead to base (or diode anode) for NPN , black lead to
base for PNP.
PS - also check any C-E for a dead short 000-005....I'm doin' this on a Japanese amp now .
OS
__________________
Mongrel website , always current and updated :
http://www.fidelityforce.com/ostripper

Last edited by ostripper; 9th November 2013 at 08:02 PM.
  Reply With Quote
Old 9th November 2013, 08:47 PM   #703
PJN is offline PJN  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Pa, USA
Hi Ostripper,

Thanks for the advise, I'll start checking. The heat sink on Q11/12 is a bit thick but I did check the transistors, and none were shorting out to the heat sink.

PJN
  Reply With Quote
Old 10th November 2013, 11:01 AM   #704
cod3gen is offline cod3gen  Norway
diyAudio Member
 
Join Date: Nov 2007
Send a message via MSN to cod3gen
What could cause high current through R25? It has got dark, and Q9 seems to have some heat to it.
  Reply With Quote
Old 11th November 2013, 01:32 PM   #705
PJN is offline PJN  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Pa, USA
Hi Guys,

R25 is fine, the picture makes it look dark I checked it again and it's Ok.

Here are the results of checking things with the diode setting of my DMM
Diode checks :
D1 : 0.005 (looks bad, I checked new spares and they read 0.716)
D2 : 0.005 (bad ?)
D3 : 0.847
D4,5,7, 8 &9 : 0.635 to 0.655
D6 (red led, reads 1.55 and dimly lights up)
D7(blue led, reads 1, doesn’t light up, maybe burnt out, was installed with correct polarity as shown on board)
Transistor checks :
Q 1,2,3,4(NPN) B – C : 0.826 – 0.861, B-E : 0.829 – 0.863, C-E – 1
Q 5 (PNP) B-C : 0.83, B-E : 0.835, C-E : 1.215
Q 6 (PNP) B-C : 0, B-E : 0.756 C-E : 0.754 (looks bad)
Q 7 (NPN) B-C : 0.823, B-E : 0.826, C-E : 1.132
Q 8 (NPN) B-C : 0.76, B-E : 0.279 C-E : 0.915 (B-E very different is this bad ?)
Q 9 (PNP) B-C : 0.815, B-E : 0.821, C-E : 1.89
Q 10 (PNP) B-C : 0.113, B-E : 0.821, C-E : 0.861
Q 11 (NPN) B-C : 0.668, B-E : 0.167, C-E : 0.813(B-E very different is this bad ?)
Q 12 (NPN) B-C : 0.757, B-E : 0.763, C-E : 0.816
Q 13 (NPN) B-C : 0.757, B-E : 0.763, C-E : 0.816
Q 14 (NPN) B-C : 0.757, B-E : 0.763, C-E : 0.816
Q 15 (PNP) I installed the wrong transistor, put a MJE15032 here instead of MJE15033, I screwed up when placing the order. I’ll need to replace this with the correct part.
Q 16,17,18 (NPN) B-C : 0.618, B-E : 0.623, C-E : 1.28
Q 19,20,21 (PNP) B-C : 0.583, B-E : 0.595, C-E : 0.638
So it looks like my mistake with Q15 cost me, D1 & D2 are bad, D7 is burned out, Q6 is bad, Q8 & Q11 look questionable. I’ll replace Q15 and these other parts and give it another try. Thanks for your guidance.
PJN
  Reply With Quote
Old 11th November 2013, 05:16 PM   #706
diyAudio Member
 
ostripper's Avatar
 
Join Date: May 2008
Location: Albany , NY (smallbany)
Quote:
Originally Posted by PJN View Post
Hi Guys,

R25 is fine, the picture makes it look dark I checked it again and it's Ok.

Here are the results of checking things with the diode setting of my DMM
Diode checks :
D1 : 0.005 (looks bad, I checked new spares and they read 0.716)
D2 : 0.005 (bad ?)
D3 : 0.847
D4,5,7, 8 &9 : 0.635 to 0.655
D6 (red led, reads 1.55 and dimly lights up)
D7(blue led, reads 1, doesn’t light up, maybe burnt out, was installed with correct polarity as shown on board)
Transistor checks :
Q 1,2,3,4(NPN) B – C : 0.826 – 0.861, B-E : 0.829 – 0.863, C-E – 1
Q 5 (PNP) B-C : 0.83, B-E : 0.835, C-E : 1.215
Q 6 (PNP) B-C : 0, B-E : 0.756 C-E : 0.754 (looks bad)
Q 7 (NPN) B-C : 0.823, B-E : 0.826, C-E : 1.132
Q 8 (NPN) B-C : 0.76, B-E : 0.279 C-E : 0.915 (B-E very different is this bad ?)
Q 9 (PNP) B-C : 0.815, B-E : 0.821, C-E : 1.89
Q 10 (PNP) B-C : 0.113, B-E : 0.821, C-E : 0.861
Q 11 (NPN) B-C : 0.668, B-E : 0.167, C-E : 0.813(B-E very different is this bad ?)
Q 12 (NPN) B-C : 0.757, B-E : 0.763, C-E : 0.816
Q 13 (NPN) B-C : 0.757, B-E : 0.763, C-E : 0.816
Q 14 (NPN) B-C : 0.757, B-E : 0.763, C-E : 0.816
Q 15 (PNP) I installed the wrong transistor, put a MJE15032 here instead of MJE15033, I screwed up when placing the order. I’ll need to replace this with the correct part.
Q 16,17,18 (NPN) B-C : 0.618, B-E : 0.623, C-E : 1.28
Q 19,20,21 (PNP) B-C : 0.583, B-E : 0.595, C-E : 0.638
So it looks like my mistake with Q15 cost me, D1 & D2 are bad, D7 is burned out, Q6 is bad, Q8 & Q11 look questionable. I’ll replace Q15 and these other parts and give it another try. Thanks for your guidance.
PJN
D1,2 = toast
Your blue led is most likely good , DMM does not have enough Voltage
to forward bias it.
By having the wrong driver , you most likely "stressed" the VAS , even if
they are not total "toast" , they might not be reliable long term.
The input stage/cascode run on a separate CRC supply and most likely are
fine.

This is why I run them 68R resistors from the driver emitters to L1 with the outputs disconnected.
Even if I put in a wrong part (I done it , too ), the error would equate to mA's instead of
AMP's !!
OS
__________________
Mongrel website , always current and updated :
http://www.fidelityforce.com/ostripper
  Reply With Quote
Old 11th November 2013, 07:00 PM   #707
RINNAV is offline RINNAV  United States
diyAudio Member
 
Join Date: Jan 2012
Power Supply test complete--62.5 volts + and - read good! I Just have one LED to straighten out = aggravating ...
Attached Images
File Type: jpg Power Supply Test.jpg (346.5 KB, 392 views)
  Reply With Quote
Old 13th November 2013, 05:20 PM   #708
PJN is offline PJN  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Pa, USA
While I was waiting for spare parts to arrive I thought that I'd study the schematic a bit. It turns out that B &C for Q6 are tied together so that's why the B-C reading was 0 so it looks like Q6 is fine. D1 and D2 are also fine taking a reading across either would just return the value of R4 (5R)because of the way the tracks are laid out. I pulled them off of one board and sure enough once out they tested fine (0.716). I also replaced Q11 which I though might have been bad using the diode test since the B-E diode reading was 0.167, with the new replacement the B-C reading is still 0.167 so it looks like Q11 was fine. this leads me to believe that Q8 is also fine. So for right now I'll just resist the urge to get out my hammer and smash these boards to bits, and just wait calmly for the spare parts for Q15 to come in and give it another try.

PJN
  Reply With Quote
Old 14th November 2013, 02:06 AM   #709
diyAudio Member
 
ostripper's Avatar
 
Join Date: May 2008
Location: Albany , NY (smallbany)
Quote:
Originally Posted by PJN View Post
While I was waiting for spare parts to arrive I thought that I'd study the schematic a bit. It turns out that B &C for Q6 are tied together so that's why the B-C reading was 0 so it looks like Q6 is fine. D1 and D2 are also fine taking a reading across either would just return the value of R4 (5R)because of the way the tracks are laid out. I pulled them off of one board and sure enough once out they tested fine (0.716). I also replaced Q11 which I though might have been bad using the diode test since the B-E diode reading was 0.167, with the new replacement the B-C reading is still 0.167 so it looks like Q11 was fine. this leads me to believe that Q8 is also fine. So for right now I'll just resist the urge to get out my hammer and smash these boards to bits, and just wait calmly for the spare parts for Q15 to come in and give it another try.

PJN


Have patience.

Some semiconductors will be affected by their associated components.
I neglected to tell you that not every one would read the same (B-E,B-C).

I actually simulated the Badger with your reversed (wrong driver). As I suspected ,Q9-10
drew 500ma+ - you most likely blew them... Q11-12 might also be suspect
(Replace your VAS).
The input stage/ cascode/mirror just seemed a little unbalanced , but none
conducted more than a few mA's (fine).

I know it is only simulated , but I have done this before to mirror my
major errors and what Spice predicted as "blown" was indeed "toast" .

OS
__________________
Mongrel website , always current and updated :
http://www.fidelityforce.com/ostripper
  Reply With Quote
Old 14th November 2013, 07:32 PM   #710
PJN is offline PJN  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Pa, USA
Hi Guy's

I'm back again without success, I replaced Q10,Q11,& Q12 in the VAS section (Q10,Q11,Q12), replaced Q15 with the correct one, replaced R8, R9, R15, R16, &R26 with 10R (got 100K mislabled from digikey). Tested all of the transistors with the diode function on my DMM all read fine. Replaced D1 & D2 although it turns out that they were good when I tested them after I removed them. Replaced Q8 which also turned out to be fine when I tested it after it was removed. When I apply power D7 (blue led, (-) rail) now lights and I get very low voltage (0.003) across the 10R resistors across F2. But D6 (red led,(+) rail) does not light up and I read the full rail voltage (62.3 vdc) across the 10R resistor across F1. The resistor across F1 does not get warm. and the DC offset reads -62.3 vdc. I checked all of the transistors on the heat sink and none are grounding out to the sink, and none of the VAS transistors on the little heat sink are grounding out to the little sink. I checked R32 to see if it burned out to prevent currend from lighting up D6 and it's fine and reading 22R, checked D6 and it's also fine. Where should I look from here ? Has anyone else used the ver 2.3 boards ?

Thanks,

PJN
  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
diyAB Amp - The "Honey Badger" Variac Solid State 1331 19th September 2014 07:35 PM
My LM3886 build thread CanAm Man Chip Amps 22 13th July 2012 07:48 AM
Ricci's dual B&C 21SW152 build thread. Josh Ricci Subwoofers 22 12th April 2010 09:39 PM
New Project Build Thread ryoung Multi-Way 5 19th April 2008 01:15 AM
Badger Badger Badger..... Mushroom !! 5th element Everything Else 15 20th September 2003 03:16 PM


New To Site? Need Help?

All times are GMT. The time now is 09:43 AM.


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