BA-3 Amplifier illustrated build guide
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 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
MASantos
diyAudio Member

Join Date: May 2005
Location: Lisbon Portugal
Quote:
 Originally Posted by AndrewT most heatsinks are rated for a deltaT of 70C to 80C degrees. most heatsink manufacturers issue de-rating data/tables for their heatsinks when DeltaT is less. For a deltaT of around 13C degrees expect the de-rating factor to exceed 1.5 i.e. 60W into 0.2C/W and using a DF of 1.6 gives DeltaT = 60 *0.2 *1.6 = 19.2Cdegrees If Ta = 28°C, then Ts = 47°C
Since hifi2000 doesn't provide us with such data, the best we can do is to follow Papa's rules: always get the biggest heatsink you can, and after that use the palm rule! I have a small infrared laser thermometre, so that helps!

2 picoDumbs
diyAudio Member

Join Date: Sep 2013
Quote:
 Originally Posted by AndrewT For a deltaT of around 13C degrees expect the de-rating factor to exceed 1.5 i.e. 60W into 0.2C/W and using a DF of 1.6 gives DeltaT = 60 *0.2 *1.6 = 19.2Cdegrees
19.2 is pretty close to my estimated value of 20 after derating
I always knew deep down I couldn't be too dumb.

Hahahahaha
__________________
"If you leave this point unattached to some circuitry, an ideal constant current source will emit a small lightning bolt which will travel until it connects to something." Nelson Pass

2 picoDumbs
diyAudio Member

Join Date: Sep 2013
Quote:
 Originally Posted by MASantos Since hifi2000 doesn't provide us with such data, the best we can do is to follow Papa's rules: always get the biggest heatsink you can, and after that use the palm rule! I have a small infrared laser thermometre, so that helps!
No need to lose sleep over this, I have that very case you are inquiring about, the heat sinks can easily do what you are asking them to do.
__________________
"If you leave this point unattached to some circuitry, an ideal constant current source will emit a small lightning bolt which will travel until it connects to something." Nelson Pass

 12th June 2016, 09:53 PM #104 Tyson   diyAudio Member   Join Date: Feb 2009 I have a bit of an odd question regarding the BA3 I built together with 6l6(Jim). I'd like to change out the 10uf caps on the input board to a smaller value, so that the amp will roll off the signal below 150hz. What cap value should I change in order to make that happen? You might wonder why I want to do this.... its because my speakers run planar magnetic drivers for the midrange and I'd like to only send them a signal from 150hz and up. I have a separate bass section that has it's own amps, so I don't need a full range signal from the BA3. I know that the formula to calculate this is: 1/RC = 6.3 * F R= ohms C = farads (not microfarads) F = frequency I know that F will equal 150, but I need to know the input impedance of the BA3's output boards (I'm using the complimentary, push-pull boards from the DIY Audiostore). Does anyone know their input impedance? Because that should give me R, and then I can calculate C.
 12th June 2016, 11:14 PM #105 Zen Mod   Official Court Jester diyAudio Member     Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain aroundish 5-6K __________________ 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
 13th June 2016, 04:04 AM #106 Tyson   diyAudio Member   Join Date: Feb 2009 THANKS Zen Mod! So if my math is correct, I'd need a .2uF cap - does that sound right?
 13th June 2016, 08:09 AM #107 Zen Mod   Official Court Jester diyAudio Member     Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain yup __________________ 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
 10th December 2016, 07:34 PM #108 qwertyl   diyAudio Member   Join Date: Apr 2003 Location: UK Today I did a bit of listening to my newly built BA-3 (front end + power amp in separae chassis). I am impressed by dynamic, control, resolution, very delicate high frequencies, but comparing to Aleph J there is less colours, less presence and human voices sound a bit worse - is this something that can be cured by adjusting P3? I haven't touched it yet. Aleph J sounds better at low volumes, BA-3 I kept increasing volume, it is very relaxed. __________________ Builds: M2, Aleph J, B1 Korg, Pearl II, BA-3 Pre, BA-3 Power, F4, Sony VFET, 300B SET, Audio Note AN-E Last edited by qwertyl; 10th December 2016 at 07:36 PM.
Zen Mod
Official Court Jester
diyAudio Member

Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Quote:
 Originally Posted by qwertyl .....is this something that can be cured by adjusting P3?......
yup
__________________
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

 10th December 2016, 08:59 PM #110 6L6   diyAudio Moderator     Join Date: Oct 2010 Location: Denver, Colorado Also you are hearing the differences between the AJ and the BA-3... The BA is pretty neutral whereas Alephs are quite colored, but the colors are so incredibly beautiful that nobody cares. The BA-3 is still my favorite amp, with the AJ in a very close second, despite their differences. As ZM says, you can adjust P3 and tune to taste. __________________ Illustrated Build Guides - Pass F4 - Pass B1 - Pass F5 - Pearl 2 - O2 HPA - Hagerman Bugle 2 - Pass Aleph J - Me at BA '13 -Pass F5Turbo - BA-3 Amp - BA-3 Preamp - F6 AmpCampAmp Me at BAF '18https://www.youtube.com/watch?v=pl0GniCEoVk

 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 Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Room Acoustics & Mods     Music     diyAudio.com Articles     Car Audio     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Holton Precision Audio         CSS         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post 6L6 Pass Labs 3374 Today 03:48 AM 6L6 Pass Labs 1338 18th January 2019 07:24 AM 6L6 Power Supplies 786 4th January 2019 01:52 AM 6L6 Pass Labs 153 24th November 2018 08:18 AM 6L6 Pass Labs 472 30th September 2018 06:15 PM

 New To Site? Need Help?

All times are GMT. The time now is 08:17 PM.