Burning Amplifier BA-2 - Page 107 - diyAudio
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 14th March 2013, 07:41 PM   #1061
diyAudio Member
 
Join Date: Jul 2004
Location: Minnesota
Default and more

regards, Matt
Attached Images
File Type: jpg IMG_5099.jpg (967.7 KB, 314 views)
File Type: jpg IMG_5100.jpg (447.8 KB, 281 views)
File Type: jpg IMG_5101.jpg (710.5 KB, 226 views)
File Type: jpg IMG_5102.jpg (414.3 KB, 216 views)
  Reply With Quote
Old 15th March 2013, 10:15 AM   #1062
diyAudio Member
 
Join Date: Sep 2008
Hi Matt
That photo above, second from right, shows the speaker out terminals right? The central connection of each terminal, one is wired for output from the power boards and one from ground, correct? Oh I think I can see you have.
Chris

Last edited by Backbones; 15th March 2013 at 10:18 AM.
  Reply With Quote
Old 15th March 2013, 10:21 AM   #1063
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
Is that plate holding the mosfets down?
__________________
...Shape the sound , Man!
  Reply With Quote
Old 15th March 2013, 10:22 AM   #1064
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
how you wired that XLR and switch above ?
__________________
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 15th March 2013, 10:54 AM   #1065
diyAudio Member
 
Join Date: Jul 2004
Location: Minnesota
Default BA-2 problems

Backbones: Yes, the OUT from the output boards goes to the + speaker out terminal. The (-) speaker out terminal goes to the signal ground. Thanks!

buzzforb: The plate is just holding the output board against the sink. There are 6 standoffs on the board, the plate holds the board stable, and I verified that no metal from the holddown plate is touching any exposed traces on the board. Each MOSFET is secured to a tapped hole on the sink with compound and pads between the mosfet and sink. Thanks.

ZM: I have rca and xlr inputs. switch is used to ground pin 3 of the xlr to pin 1 when the rca input is used. All connections have been verified as correct. Thanks.

Matt
  Reply With Quote
Old 15th March 2013, 04:33 PM   #1066
diyAudio Member
 
Join Date: Sep 2008
Hi Matt,
I know this might sound wrong headed but have you actually wired up some speakers (not the good ones) and listened?
After all if the bias has been set and you can adjust the dc offset then the power boards are working fine. Could be the front end by a process of elimination.
Chris
  Reply With Quote
Old 15th March 2013, 05:36 PM   #1067
diyAudio Member
 
Join Date: Jul 2004
Location: Minnesota
Default trouble with BA-2 mono

Backbones: Hi Chris, yes, I did hook one up, did get sound, very quiet, then stopped as I increased the volume, as the 1.5amp fuse I had onboard blew. Same result with both monoblocks and even one monoblock with another gain stage board that I assembled with totally new components, all checked for proper values.

I have looked at these front end boards many times, and checked the components for orientation, value, etc, but plan to do that all over again this weekend.
Matt
  Reply With Quote
Old 25th March 2013, 09:58 AM   #1068
diyAudio Member
 
Join Date: Sep 2008
Hi Matt,
How are things progressing? Two things that came to mind whilst doing nothing in particular over the weekend were: fake components on the semiconductor side and the other as to whether you have disconnected the front end and fed a signal into the power boards directly to see how they behaved.
Best wishes,
Chris
  Reply With Quote
Old 26th March 2013, 02:33 PM   #1069
diyAudio Member
 
Join Date: Jul 2004
Location: Minnesota
Default BA-2 problems

Hi Backbones:

I am in the process of totally rebuilding one of the gain boards with new parts to see if I can get the proper voltage gain at the board output.

I had worried about counterfeits, too, but the 2SK parts all tested within the appropriate ranges using the listed testing procedures within this string and other Pass strings.

Once I get that done (having a hip replacement in about 2 weeks, so it is putting DIY on the back burner again) I will report back.

Thanks,
Matt
  Reply With Quote
Old 3rd June 2013, 03:21 PM   #1070
mns80 is offline mns80  Finland
diyAudio Member
 
Join Date: Sep 2010
Hi Guys, what do you think about these? I am thinking BA-2 output paired with BA-3b. Cut these babies in half and use two pieces per mono. ~6 FETs per corner was the idea but that is still on the drawing table..
Attached Images
File Type: jpg IMG_6235.jpg (59.6 KB, 105 views)
  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
Burning Amplifier BA-2 Nelson Pass diyAudio.com Articles 5 14th September 2011 06:11 PM
The Burning Amp Festival-Burning Gadgets Preview Zen Mod Everything Else 115 27th October 2007 05:50 PM


New To Site? Need Help?

All times are GMT. The time now is 05:35 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