Burning Amp BA-3b (Balanced) - Page 11 - 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 1st December 2011, 01:12 PM   #101
generg is offline generg  Germany
diyAudio Member
 
generg's Avatar
 
Join Date: Jul 2009
Location: Near Frankfurt
Better connect - out to the ground and use +out and ground for the output stage.

In the other case + and - combined = zero ....

Excuse my bad English....
__________________
and the First Wtt is......a really First Class PSS Idea
  Reply With Quote
Old 1st December 2011, 01:36 PM   #102
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Quote:
Originally Posted by generg View Post
Thanks Zen Mod the switch is a very good idea to test the sound difference between a half dead BBA-3 and a complete alive BA-3!
so , conclusion after test is ........

?

__________________
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 1st December 2011, 01:52 PM   #103
generg is offline generg  Germany
diyAudio Member
 
generg's Avatar
 
Join Date: Jul 2009
Location: Near Frankfurt
Oh, sorry Zen Mod, was too lazy today......

Was only hearing and enjoying music.......

The only experiment I made was to go from 1:5 to 1:2,5 with the xformer before F4 and to my great surprise the sound got darker...... Maybe the RC correcting the resonance is now to active.....

Have a lazy day too, weather here is for the first time dull ... .! As it should be in November.
__________________
and the First Wtt is......a really First Class PSS Idea
  Reply With Quote
Old 1st December 2011, 03:16 PM   #104
rsdio is offline rsdio  United States
diyAudio Member
 
Join Date: Feb 2008
Location: Seattle
Quote:
Originally Posted by generg View Post
Better connect - out to the ground and use +out and ground for the output stage.
That's a bad idea if you use 0 Ω for the connection between -out and ground. This can distort most balanced output circuits. In the specific case of the BA-3b, there is already 100 Ω*and capacitance on the output to save you from certain destruction, but at a minimum a grounded -out circuit will be working harder than the +out section that's driving a non-zero impedance.

Better to match the input impedance that you've connected the +out to, and use that same resistance between -out and ground. For some circuits you can just leave -out floating for best results.
  Reply With Quote
Old 1st December 2011, 07:56 PM   #105
generg is offline generg  Germany
diyAudio Member
 
generg's Avatar
 
Join Date: Jul 2009
Location: Near Frankfurt
yes I wrote it this way because BA-3 has a cap and 100 Ohm....

I tried with pumpkin balanced in and unbalanced out both variants, neg output closed and open.

For me the sound with closed neg output had more bass......and dynamics so I decided this way....
__________________
and the First Wtt is......a really First Class PSS Idea
  Reply With Quote
Old 2nd December 2011, 04:05 AM   #106
rsdio is offline rsdio  United States
diyAudio Member
 
Join Date: Feb 2008
Location: Seattle
Quote:
Originally Posted by generg View Post
I tried with pumpkin balanced in and unbalanced out both variants, neg output closed and open.

For me the sound with closed neg output had more bass......and dynamics so I decided this way....
You might try a third option: A resistor with a value that matches the impedance of your unbalanced load as closely as possible. That way you're not overworking the "unused" output.
  Reply With Quote
Old 2nd December 2011, 06:19 AM   #107
generg is offline generg  Germany
diyAudio Member
 
generg's Avatar
 
Join Date: Jul 2009
Location: Near Frankfurt
Yes I will try it, thanks!

Maybe I will try the same with the unused imput...... tuner output is of course unbalanced...
__________________
and the First Wtt is......a really First Class PSS Idea
  Reply With Quote
Old 2nd December 2011, 10:42 AM   #108
rsdio is offline rsdio  United States
diyAudio Member
 
Join Date: Feb 2008
Location: Seattle
Quote:
Originally Posted by generg View Post
Maybe I will try the same with the unused imput...... tuner output is of course unbalanced...
Hmm, I don't think it's quite the same thing, though. Balanced input is not the same thing as balanced output. An input is not going to distort from excessive current when it is grounded, so there seems to be no danger in grounding via 0 Ω.

That said, if you know the output impedance of your tuner, then you could ground the unused input through a resistor that matches the output impedance. It wouldn't hurt to try, but my hunch is that you'll end up with thermal noise from the resistor that could be avoided by skipping the resistor altogether.
  Reply With Quote
Old 2nd December 2011, 10:46 AM   #109
generg is offline generg  Germany
diyAudio Member
 
generg's Avatar
 
Join Date: Jul 2009
Location: Near Frankfurt
Accepted! THX
__________________
and the First Wtt is......a really First Class PSS Idea
  Reply With Quote
Old 2nd December 2011, 06:36 PM   #110
steveu is offline steveu  United States
diyAudio Member
 
Join Date: May 2005
Location: Colorado Springs
High power often means that larger, slower transistors are needed which may adversely affect sound quality, especially for older designs. A Mac truck does not do well on the slalom run. On the other hand, a large amp is probably not as sensitive to load impedance nasties. A very real problem with large amps is that they can fry your drivers in milliseconds. This is a very important reasons it's better to use a separate amp for each driver/band, and use an electronic crossover. ie keep the high end driver amp power no bigger than necessary.
  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 Amp BA-3 Backbones Pass Labs 1695 3rd July 2014 12:25 AM
Burning Amplifier BA-2 Variac Pass Labs 1125 1st July 2014 01:39 PM
Burning Amplifier BA-2 Nelson Pass diyAudio.com Articles 5 14th September 2011 06:11 PM
WTB: Burning Amp BA-1 or BA-2 jdubs Swap Meet 0 23rd March 2011 03:16 AM
FS: two burning amps (one each BA-1 and BA-2) without drivers Eric Weitzman Swap Meet 15 17th February 2010 02:35 AM


New To Site? Need Help?

All times are GMT. The time now is 06:59 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