made this one, its working but there is a humming sound on the left channel even at low volume. what could be the problem?
See the datasheet footnotes section where they give you more reasonable guidelines for the component values.
However, the schematics in the datasheet have problematic values listed, resulting in heat, midfi and poor bass.
At post 111 schematic, Bass Blockers include C5, C2, which are too small.
Change C5 to within the range of 47u to 100u
Change C7 to 330u//33n (nearby values work similarily)
Change C9 to 330u//33n (nearby values work similarily)
Omit C3
If R2 is 680R, change C2 to 1000u
If R2 is 1.2k, change C2 to 470u
Change C1 to 1u
Put 1 of 2u polyester cap from V+ to V-, reducing noise for cooler running.
Notes:
Gain of 70 is not valid for this chip--R2 is probably supposed to be 1.2k for the design shown.
Above, we added some bass harmonic clairty to the power circuit with the 330u caps.
Above, we have employed the newly revised bootstrap cap size guideline for better bass.
Above, we altered the NFB cap, C2, to allow bass to pass through it.
After increasing the NFB cap, we increased the input cap, C1, to allow un-hindered bass.
And we filtered noise, because LESS heat into the heatsink means more power avaiable to speaker.
If C2 is too small, bass will be "warm" "boomy" or "missing the lowest notes"
If C2 is too big, bass will be "monotony" "thuds" or "weak drums"
But, the right size will fix it.
Please report back and post when you get thunder. 🙂
However, the schematics in the datasheet have problematic values listed, resulting in heat, midfi and poor bass.
At post 111 schematic, Bass Blockers include C5, C2, which are too small.
Change C5 to within the range of 47u to 100u
Change C7 to 330u//33n (nearby values work similarily)
Change C9 to 330u//33n (nearby values work similarily)
Omit C3
If R2 is 680R, change C2 to 1000u
If R2 is 1.2k, change C2 to 470u
Change C1 to 1u
Put 1 of 2u polyester cap from V+ to V-, reducing noise for cooler running.
Notes:
Gain of 70 is not valid for this chip--R2 is probably supposed to be 1.2k for the design shown.
Above, we added some bass harmonic clairty to the power circuit with the 330u caps.
Above, we have employed the newly revised bootstrap cap size guideline for better bass.
Above, we altered the NFB cap, C2, to allow bass to pass through it.
After increasing the NFB cap, we increased the input cap, C1, to allow un-hindered bass.
And we filtered noise, because LESS heat into the heatsink means more power avaiable to speaker.
If C2 is too small, bass will be "warm" "boomy" or "missing the lowest notes"
If C2 is too big, bass will be "monotony" "thuds" or "weak drums"
But, the right size will fix it.
Please report back and post when you get thunder. 🙂
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Bill of Materials
The list of materials is the same as the picture soguiente (Bridge Mode)
Only a matter that holds a pen and paper, copy it on a leaf and ready.
luck
The list of materials is the same as the picture soguiente (Bridge Mode)
Only a matter that holds a pen and paper, copy it on a leaf and ready.
luck
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Last edited:
Hi All,
Here is my development pcb layout of TDA7293/4 Hi-End.
Board
https://www.dropbox.com/s/s33gkokcebg342h/tda72934%20hi%20end%20with%20zobel.PNG
Schematic
https://www.dropbox.com/s/kjqjmp9y8dgl5wt/tda7293 hi end.PNG
pcb for Print (size 33x51mm)
https://www.dropbox.com/s/17p9ywqszu4prme/tda72934 hi end with zobel.pdf
And other pics
https://www.dropbox.com/s/8chr23qa19wv4q6/2013-03-23 11.35.05.jpg
https://www.dropbox.com/s/v8szrhfbcpv2iet/22122011449.jpg
On the following link you can see one of my projects with this IC
4xTDA7293 2x160W HI-END amplifier | DIY Projects
Enjoy!
BR,
Lyubo
Here is my development pcb layout of TDA7293/4 Hi-End.
Board
https://www.dropbox.com/s/s33gkokcebg342h/tda72934%20hi%20end%20with%20zobel.PNG
Schematic
https://www.dropbox.com/s/kjqjmp9y8dgl5wt/tda7293 hi end.PNG
pcb for Print (size 33x51mm)
https://www.dropbox.com/s/17p9ywqszu4prme/tda72934 hi end with zobel.pdf
And other pics
https://www.dropbox.com/s/8chr23qa19wv4q6/2013-03-23 11.35.05.jpg
https://www.dropbox.com/s/v8szrhfbcpv2iet/22122011449.jpg
On the following link you can see one of my projects with this IC
4xTDA7293 2x160W HI-END amplifier | DIY Projects
Enjoy!
BR,
Lyubo
Last edited:
Hi to all!
This is my first post to the forum and I want your opinion.I already done this amplifier and it works grate!
I want to use it as a subwoofer amp.The original amp is off and it was using a pair of 2SA1943+2SC5200 transistors and claimed to be 150 watts,and it have it’s own preamp.So what changes to the circuit do you recommend for that application?Iforgot to say that the old subamp plate has a transformer of dual 35V ac and I reduce it to dual 24V ac.I want to use this TDA7294 bridge amp because it’s small and I can put it to the sub plate.
This is my first post to the forum and I want your opinion.I already done this amplifier and it works grate!
I want to use it as a subwoofer amp.The original amp is off and it was using a pair of 2SA1943+2SC5200 transistors and claimed to be 150 watts,and it have it’s own preamp.So what changes to the circuit do you recommend for that application?Iforgot to say that the old subamp plate has a transformer of dual 35V ac and I reduce it to dual 24V ac.I want to use this TDA7294 bridge amp because it’s small and I can put it to the sub plate.
Only some photos
I have built the amplifier with TDA7293 for test purposes. It works very well and has a rich bass and very, very easy rushing heights. But absolutely ok for the price and the effort.
I made a new PCB because more space for different components from the shelf.
regards Olaf
I have built the amplifier with TDA7293 for test purposes. It works very well and has a rich bass and very, very easy rushing heights. But absolutely ok for the price and the effort.
I made a new PCB because more space for different components from the shelf.
regards Olaf
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