Manoj Sivaraman
Member
Hi,
It's been a long time since I have had hands on. So this was a project for a friend who bought a Onkyo TXNR676.
The whole speaker setup was designed with a local carpenter. The finale was with a good subwoofer, he was so fixed with 8 inchers. As he wasn't having enough space to accommodate one in his living room.
The build
We had some Logitech z906 subwoofers laying idle. So designed a cheap yet powerful class AB poweramp with dual TDA7293 in BTL mode.
The Logitech drivers are capable of handling. They are made by Tangband themselves. Comes with a aluminium voice coil and a pressed paper cone. Rated at 165w RMS.
Components:
TDA7293 BTL board.
24-0-24 E core 6A Maxine trafo.
5000mfd capacitors 2x each per rail.
metal bridge rectifier.
12-0-12 1A trafo (for pre amp low pass) and speaker protection and delay circuit.
Mono speaker protection circuit built in delay.
Lowpass filter with freq control and gain.
The whole thing was built into a plate amplifer. Made of 3mm aluminium plates and 2.5"x5"x10" heatsink.
The entire backplate acting as a heatsink as well added dissipation.
Since these are AB poweramps as per datasheet they require large heatsinks or active cooling.
Unfinished raw backplate.
Used PU rubber mat as a sound deadner on the metal backplate.
So fired up for the first time, tight and deep accurate bass as expected.
Nothing so deep or muddy just accurate enough.
Zero hums and noises.
Just a small write-up didn't have much time to write the entire build also lost most photos.
Thanks....
Some pics while performing tests...
Also some ongoing projects
It's been a long time since I have had hands on. So this was a project for a friend who bought a Onkyo TXNR676.
The whole speaker setup was designed with a local carpenter. The finale was with a good subwoofer, he was so fixed with 8 inchers. As he wasn't having enough space to accommodate one in his living room.
The build
We had some Logitech z906 subwoofers laying idle. So designed a cheap yet powerful class AB poweramp with dual TDA7293 in BTL mode.
The Logitech drivers are capable of handling. They are made by Tangband themselves. Comes with a aluminium voice coil and a pressed paper cone. Rated at 165w RMS.
Components:
TDA7293 BTL board.
24-0-24 E core 6A Maxine trafo.
5000mfd capacitors 2x each per rail.
metal bridge rectifier.
12-0-12 1A trafo (for pre amp low pass) and speaker protection and delay circuit.
Mono speaker protection circuit built in delay.
Lowpass filter with freq control and gain.
The whole thing was built into a plate amplifer. Made of 3mm aluminium plates and 2.5"x5"x10" heatsink.
The entire backplate acting as a heatsink as well added dissipation.
Since these are AB poweramps as per datasheet they require large heatsinks or active cooling.
Unfinished raw backplate.
Used PU rubber mat as a sound deadner on the metal backplate.
So fired up for the first time, tight and deep accurate bass as expected.
Nothing so deep or muddy just accurate enough.
Zero hums and noises.
Just a small write-up didn't have much time to write the entire build also lost most photos.
Thanks....
Some pics while performing tests...
Also some ongoing projects
