Burning Amp BA-3b (Balanced) - diyAudio
Go Back   Home > Forums > Blogs > My DIY projects

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
I returned to DIY electronics in 2009 after a 20 year pause by building a few kits to get in shape. This blog is for me to keep track of my progress.
Rate this Entry

Burning Amp BA-3b (Balanced)

Posted 9th April 2013 at 06:10 PM by alexcp
Updated 2nd November 2013 at 11:17 AM by alexcp (Added better photos)

Big, hot, and heavy! Just completed it and adjusted for distortion, have not had yet a real chance to listen to it. (Update: I have listened to this amp for some time, and it seems to be a keeper, at least for now.)

The build is in a 4U/400 case from modushop; each side has two 200mm heatsinks, each holding six MOSFETs (three complementary pairs) and a biasing circuit.

The construction is dual mono (separate transformers for each channel) with CRC filtered +/- 18V rails, quiescent current is 3A per channel. Eight Mundorf MLytic® HC High Current Power Caps and two 300VA toroids occupy the most of the chassis, while the actual electronics is mounted on the sides.

Now I need a balanced preamp. I contemplate building some variant of BoSoZ, but am also thinking about a SuperSymmetric balanced preamp using JFETs or tubes...

UPDATE: No- and low-feedback amplifiers have no (or little) control over output errors and thus poor PSRR. On this premise, I replaced the CRC filters in the power supply of my BA3B with CLCs, so instead of 22mF + (2 x 0.22ohm) + 22mF I now have 100mF + 10mH + 100mF per rail per channel. I still need to give it a listen after this upgrade.
Attached Thumbnails
Click image for larger version

Name:	diyaudio32.jpg
Views:	507
Size:	217.7 KB
ID:	1010   Click image for larger version

Name:	diyaudio33.jpg
Views:	664
Size:	158.8 KB
ID:	1011   Click image for larger version

Name:	diyaudio34.jpg
Views:	702
Size:	226.8 KB
ID:	1012   Click image for larger version

Name:	diyaudio35.jpg
Views:	1491
Size:	231.0 KB
ID:	1013   Click image for larger version

Name:	diyaudio36.jpg
Views:	653
Size:	242.5 KB
ID:	1014  

Click image for larger version

Name:	diyaudio37.jpg
Views:	1172
Size:	242.1 KB
ID:	1015   Click image for larger version

Name:	diyaudio39.jpg
Views:	483
Size:	156.3 KB
ID:	1016   Click image for larger version

Name:	diyaudio41.jpg
Views:	484
Size:	192.2 KB
ID:	1017   Click image for larger version

Name:	diyaudio43.jpg
Views:	512
Size:	167.0 KB
ID:	1018   Click image for larger version

Name:	diyaudio45.jpg
Views:	1638
Size:	253.2 KB
ID:	1019  

Views 2027 Comments 0 Email Blog Entry
Total Comments 0


Hide this!Advertise here!

New To Site? Need Help?

All times are GMT. The time now is 01:44 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.
Copyright ©1999-2015 diyAudio

Content Relevant URLs by vBSEO 3.3.2