That’s sounds great, I’ll for sure want to use the DC servo when the amp is used at higher power, it would be unfortunate to lose this nice feature because of the LM317/337.
Eric
Eric
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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Hi Kokanee,
That PSU will work perfectly , 20,000uf per rail with resistor snubber will give really good performance.
That PSU will work perfectly , 20,000uf per rail with resistor snubber will give really good performance.
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
According to the ST TDA7293 datasheet, the maximum supply voltage for 4 ohms load is +/- 29 V. Apparently it is preferable to parallel two or more chips for higher supply voltages and 4 ohms loads. The chips allow for that rather easily.
Best regards!
Best regards!
Yes, this thread is for technical questions and discussions. I’ll create a new thread in swap meet forum to handle the shipping logistics.
Out of curiosity, has anyone decided to just make boards using the Gerbers?
Out of curiosity, has anyone decided to just make boards using the Gerbers?
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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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😉
I’m right on the edge with my trafo and psu, I’ll probably just go for this mod right out of the gate😉
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.
For the heatsinks with 4 ohm load would you be willing to add a pic, maybe a 0.5 C/W will be ok considering you need to dissipate above 30W.
Thanks
Eric
Thanks
Eric
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.
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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Dibya,
Thanks for the info on the SGC psu pcb's from Mark Johnson. I will check them out when I build.
X,
Would cpu cooler with or without fan be overkill for heat sink ?
MM
Thanks for the info on the SGC psu pcb's from Mark Johnson. I will check them out when I build.
X,
Would cpu cooler with or without fan be overkill for heat sink ?
MM
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.
Dibya,
See the Alpha Big Boy with Buttah (ABBB) thread by X. Look at post 7 and post 20 for pics of the cpu coolers.
MM
See the Alpha Big Boy with Buttah (ABBB) thread by X. Look at post 7 and post 20 for pics of the cpu coolers.
MM
You could use those CPU coolers and no fan would be my guess (unless you plan on playing at full power continuously). If you must use a fan, use a Noctua PWM and controller set to lowest speed.
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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.