Hi All,
I would like to inquire if the Chip amp psu for the Bob Cordell Super Gainclone and Compact 3886 designed by Mark Johnson could be used for the Xmas amp project, as I have a couple of these. Tried to insert the link, hope it works.
MM
PCB available: PSU for Chipamps , such as Super Gain Clone and Compact3886
I would like to inquire if the Chip amp psu for the Bob Cordell Super Gainclone and Compact 3886 designed by Mark Johnson could be used for the Xmas amp project, as I have a couple of these. Tried to insert the link, hope it works.
MM
PCB available: PSU for Chipamps , such as Super Gain Clone and Compact3886
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Hi,
If anyone of you using more than ± 35v, These Chips can heat like fryer so make sure you got big heat sink.
At 35v , TDA7293 can produce 56W at 8ohms load , 82W at 6ohms load , 100W at 4Ohms at THD less than 0.1%.
One more thing , TDA7293 have two version , V6 is rejected batch for Chinese ODM , TV stuff like that and V7 is best batch aka Silicon lottery. ST is very shady in doing business.
If you use higher than 20-0-20 Trafo for V6 IC , it will blast like a fire cracker. Practically ST is providing fake IC to these people for pennies.
If IC is from mouser / digikey it will be V7.
If anyone of you using more than ± 35v, These Chips can heat like fryer so make sure you got big heat sink.
At 35v , TDA7293 can produce 56W at 8ohms load , 82W at 6ohms load , 100W at 4Ohms at THD less than 0.1%.
One more thing , TDA7293 have two version , V6 is rejected batch for Chinese ODM , TV stuff like that and V7 is best batch aka Silicon lottery. ST is very shady in doing business.
If you use higher than 20-0-20 Trafo for V6 IC , it will blast like a fire cracker. Practically ST is providing fake IC to these people for pennies.
If IC is from mouser / digikey it will be V7.
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Very good info, thanks.
Not much graph available for that IC.
Seems that at +/- 35Vdc the IC dissipation is 10W for 8ohm load but 30W for 4 ohm. Do I read this right ? I’d like to figure out the required heatsink per channel if I’m using my 4 ohm speakers.
Can we ask our technical questions on this thread?
Thanks
Eric
Here is how Jhofland suggests wiring the board with zeners and resistors for the high voltage mod. Use 1W resistors as the dissipation is about 1/2w. So two 15v zener diodes and two 3k9 to 4k7 1W resistors and populate C19/20/23/24 with 10uF caps. Jumper R12 and R13. Place Zener diodes across D6 and D7 with same cathode orientation. Put the 1W resistors across D4 and D5. Leave the other parts unpopulated. Pretty easy actually.
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I am using 7293 at 4ohms load with ±35v , no problem so far.
You need a big heatsink (mine is 1kg).
Funny thing in India they sell heatsink according to weight.
Hi e_fortier,
I don't know anything except it is 1Kg in Weight. It kinda overkill. They charged me less than $10 , its aluminum so i cannot complain.
Of course you can buy anodized one with specification but they are 3 times the cost.
(Again they sell in Kg).
I had plan to get anodized one but money went to Domino's & Haldirams.
Rate per Kg increases with increase in number of fins.
My country is weird. Or at least component manufacturers are weird.
I don't know anything except it is 1Kg in Weight. It kinda overkill. They charged me less than $10 , its aluminum so i cannot complain.
Of course you can buy anodized one with specification but they are 3 times the cost.
(Again they sell in Kg).
I had plan to get anodized one but money went to Domino's & Haldirams.
Rate per Kg increases with increase in number of fins.
My country is weird. Or at least component manufacturers are weird.
Nice work fellas!!
I’m right on the edge with my trafo and psu, I’ll probably just go for this mod right out of the gate
Haha, me too. I probably have some +/-42v supplies to try here too.
30w is under load. Idle quiescent current is not going to be 30w.
A chassis like this would be about perfect for this amp. I have used one for a 35W dissipation per side Class A and it worked fine:
US $98.00 | BZ-15 CNC All Aluminum Chassis Case Box for DIY Audio Power Amplifier 240*120*258mm
BZ 15 CNC All Aluminum Chassis Case Box for DIY Audio Power Amplifier 240*120*258mm|Amplifier| - AliExpress
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Hi Kokanee,
I hope you don't mean those crappy one Intel provide you in box.
It depends on the size of your heat sink.
If you have lab PSU , try running those ic at ± 25v then ramp up slowly and see if it is cooling properly if not add those fans.
Hope it helps. Can i have image of your CPU cooler?
I believe XRK can help you in this regard.
I hope you don't mean those crappy one Intel provide you in box.
It depends on the size of your heat sink.
If you have lab PSU , try running those ic at ± 25v then ramp up slowly and see if it is cooling properly if not add those fans.
Hope it helps. Can i have image of your CPU cooler?
I believe XRK can help you in this regard.
Hi Myles,
You know, the thought crossed my mind also. The Dell FD841 coolers with the large copper pad will fit the TDA7293 and have no problem dissipating the heat.