Xmas Amp - Dibya's TDA7293 by Jhofland

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Vunce, X,

I bought a bunch(10) of the cpu coolers when I thought I was going to build an arsenal of Class A amps. I only have the AN, VSQA, and maybe the ACA (JPS pcb) left to build for Class A.

I am assuming one cooler per channel for each of the amps above (based on 100W dissipation) for a rough estimation, which would leave me with 4 coolers left. I would like to try a couple on shaan's V4H amp, which would leave me with 2 coolers either for the Xmas amp or an extra 2 if needed on the Nirvana.

With the AN and the VSQA, I may just keep the ACA pcbs in storage for a rainy day or sell them, as they may not be needed.

Anyways, good to hear that they could be used.

MM
 
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We should create a waiting list in case some folks in the original list don’t follow through with shipping charges etc.

I would do more but packing these and making mail labels and collecting funds is a lot of work. 25 packages is about 3 hours of work minimum to pack and ship. You guys are welcome to make your own giveaway if anyone is up to doing it.

Xmas Amp Giveaway list:
MaxReboBand / 2 boards / USA
as8912 / 2 boards / USA
ahtllc / 2 boards / USA
dBel84 / 2 boards / USA
Flamethrower1 /2 boards/ USA
Signal Lost / 2 boards / USA
diy.tiger / 2 boards / NZ
MShipmanPE/ 2 boards / USA
Angchuck / 2 boards / Singapore
Francois G / 2 boards / USA
Asuslover /2 boards /USA
Guerilla / 2 boards /Denmark
astromo / 2 boards / Australia
Kay Pirinha / 2 boards / Germany
pinkfloyd4ever/ 2 boards / USA
Sixto / 2 boards / USA
Tubesguy / 2 boards / USA
E_Fortier / 2 boards / Canada
Hicoco / 2 boards / France
Liva / 2 boards / Canada
Kokanee / 2 boards / Canada
chermann/ 2 boards / Austria
twocents/ 2 boards / USA
s610adam / 2 boards / USA
hochopeper/ 2 boards / Australia

Waiting List:
1883 / 2 boards / ?country?
Jlevro / 2 boards / USA
 
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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

Thanks a lot X.

Your enclosure link has heatsinks (250x40x120) of 0.45 C/W per channel so awesome.

BR,
Eric
 
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I Guerilla am bailing out, so I guess my two boards should go to 1883. I shouldnt learn more electronics before Ive sold of my many surplus hifi devices. My wife would agree, and I really want to keep her too. Thank you for the generous gift-offer. If I will need a 100watts amp. I will try to find it in swapmeet. I wish you all continuesly happy holidays.
Cheers!
 
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Xmas amp giveaway list update

MaxReboBand / 2 boards / USA
as8912 / 2 boards / USA
ahtllc / 2 boards / USA
dBel84 / 2 boards / USA
Flamethrower1 /2 boards/ USA
Signal Lost / 2 boards / USA
diy.tiger / 2 boards / NZ
MShipmanPE/ 2 boards / USA
Angchuck / 2 boards / Singapore
Francois G / 2 boards / USA
Asuslover /2 boards /USA
Guerilla / 2 boards /Denmark * cancelled*
astromo / 2 boards / Australia
Kay Pirinha / 2 boards / Germany
pinkfloyd4ever/ 2 boards / USA
Sixto / 2 boards / USA
Tubesguy / 2 boards / USA
E_Fortier / 2 boards / Canada
Hicoco / 2 boards / France
Liva / 2 boards / Canada
Kokanee / 2 boards / Canada
chermann/ 2 boards / Austria
twocents/ 2 boards / USA
s610adam / 2 boards / USA
hochopeper/ 2 boards / Australia
1883 / 2 boards / USA *added from waiting list*

Waiting list
Jlevro/ 2 boards / USA
 
I’ve decided to bow out of this as well. While it would be interesting to compare to the Mauro Penesa LM3886 amp of somewhat similar design, my free time and funds are fairly limited. So I’ve decided to stay focused on my main goal of building a very nice SE Class A amp of Pass lineage, and also maybe play around with some tubes...after finishing my other projects that are currently in progress.

Thanks again though to x, jhofland, and dibya. I very much appreciate the offer.

I believe this leaves 1 pair of Xmas amp boards up for grabs.
 
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Update on Giveaway Xmas amp:
MaxReboBand / 2 boards / USA
as8912 / 2 boards / USA
ahtllc / 2 boards / USA
dBel84 / 2 boards / USA *Cancelled *
Flamethrower1 /2 boards/ USA
Signal Lost / 2 boards / USA
diy.tiger / 2 boards / NZ
MShipmanPE/ 2 boards / USA
Angchuck / 2 boards / Singapore
Francois G / 2 boards / USA
Asuslover /2 boards /USA
Guerilla / 2 boards /Denmark * cancelled*
astromo / 2 boards / Australia
Kay Pirinha / 2 boards / Germany
pinkfloyd4ever/ 2 boards / USA * cancelled *
Sixto / 2 boards / USA
Tubesguy / 2 boards / USA
E_Fortier / 2 boards / Canada
Hicoco / 2 boards / France
Liva / 2 boards / Canada
Kokanee / 2 boards / Canada
chermann/ 2 boards / Austria
twocents/ 2 boards / USA
s610adam / 2 boards / USA
hochopeper/ 2 boards / Australia
1883 / 2 boards / USA
Jlevro / 2 boards / USA * added from waiting list *

Still 2 boards left

Thank you, Dbel84 and Pinkfloydforever.
 
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It’s yours!

MaxReboBand / 2 boards / USA
as8912 / 2 boards / USA
ahtllc / 2 boards / USA
dBel84 / 2 boards / USA *Cancelled *
Flamethrower1 /2 boards/ USA
Signal Lost / 2 boards / USA
diy.tiger / 2 boards / NZ
MShipmanPE/ 2 boards / USA
Angchuck / 2 boards / Singapore
Francois G / 2 boards / USA
Asuslover /2 boards /USA
Guerilla / 2 boards /Denmark * cancelled*
astromo / 2 boards / Australia
Kay Pirinha / 2 boards / Germany
pinkfloyd4ever/ 2 boards / USA * cancelled *
Sixto / 2 boards / USA
Tubesguy / 2 boards / USA
E_Fortier / 2 boards / Canada
Hicoco / 2 boards / France
Liva / 2 boards / Canada
Kokanee / 2 boards / Canada
chermann/ 2 boards / Austria
twocents/ 2 boards / USA
s610adam / 2 boards / USA
hochopeper/ 2 boards / Australia
1883 / 2 boards / USA
Jlevro / 2 boards / USA
nautibuoy / 2 boards / UK
 
Merry Christmas every one
since its a TDA7293 post may i ask for why i cant get a full power from that CHIP?
im using a trasnformer 24-0-24and 3300uF capacitors at power supply and wiring is identical to datasheet
i get a low volume when i measure its AC voltage amplitude it turned to be from 6 to 10 volt AC and even other family chips TDA7296 , TDA7295 ,TDA7294 ..... the sound is clear and good but volume doesnt seem to be even 25w ?
btw i tested a 8R speaker and 4R speaker it didnt differ a lot ...is this a fake CHIP?
help plelase
 
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@Vindiesel: Sorry I can’t answer your question. I’ll let you know once mine is built.

Hi Folks, Happy New Year!

Vunce made great progress on the verification build. It’s all powered up and the new zener diode HV supply mod is working perfectly. We are running into something with the DC offset servo though as it’s not hitting 0mV (offset at 41mV). So we are debugging that.

I expect first sound soon though, 41mV DC offset, notwithstanding.
 

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I wanted to add this info,
The TDA7293 chip is mounted on a 140mm x 65mm x 40mm heatsink with a ceramic TO-264 insulator between. After an hour of playing music at a moderate level, (just loud enough to still be able to talk to another person in the room), the heatsink temperature is 35°C (ambient temp 21°C) with a +/-36v psu. After a run of several Class A amplifiers this is barely warm :rofl:
 

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Hi Vunce, Thanks for building the verification build.
I think your speakers are 8ohms , on 4 ohms it's nice room heater in winter.
Nevertheless , it's produces much less heat than lm3886 due efficient DMOS stage.
Of course my vintage Philips speakers are 82db/w/m on top of being 6ohms. (All hail inefficiency).
 
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.
Vunce, you have a problem. :D Better keep a fire extinguisher at hand while listening. Where did you get those TDA chips?
 

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