Xmas Amp - Dibya's TDA7293 by Jhofland

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#244
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#245
keantoken said:
XRK, your flat-topped mains waveform actually improves the DC regulation of your linear power supply.

I cannot find a connection between the output and feedback on the PCB. R1 appears to be labeled P1 for some reason.

Generic ceramic insulators (alumina or aluminum oxide) are actually quite awful, please do not use these. They are mainly for high voltages and are far too thick to even approach sil-pads. Laird Keratherm is available from the DIYAudio store, in just the right size for the 7293 and is hard to beat.
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Hi Kean,
Thanks for dropping by.

So I should thank my local power company for the flat top sine wave power? It may be more efficient, but doesn’t that generate higher order harmonics?

I saw a review paper (can’t seem to find it) where the thermal conductivity between mica, silicone, Keratherm, and aluminum oxide were compared for transistor heat sink insulators. The ceramic was better than all of them. I can attest that the pad transfers 150w of dissipation from a TO-264 IXYS to a CPU cooler just fine continuously for days on days. Keeping the transistor body at 75C. Look at the thermal conductivity of aluminum oxide (circa 28 W/m K). Mine are 1mm thickness and with a thin layer of thermal grease, work well for Class A amps and so works splendidly for Class AB. They are quite durable and inexpensive too compared to Keratherm. You should try them. I use them exclusively now on my discrete Class A amps.

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The lack of a feedback trace you seek is on the backside. It is short and direct from one pin to the other. The “P1”’label is actually R1 but part of it got lost from an unfortunate overlap with a tented via.

Cheers,
X
 

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#246
Francois G said:
Turion64,

This was a free-pay-shipment offer by our friend X. There is a waiting list (see post #228) that may be filled due to non-payment by people on the list. Copy the whole list and add your name to the waiting list. If there is further demand I expect X to offer the PCBs in his Etsy Store in due time:

XRKAudio designs for superb natural sound. by XRKAudio on Etsy
Click to expand...

MaxReboBand / 2 boards / USA
as8912 / 2 boards / USA
ahtllc / 2 boards / USA *Paid Twice!!*
Flamethrower1 /2 boards/ USA *Paid*
Signal Lost / 2 boards / USA *Paid*
diy.tiger / 2 boards / NZ *Paid*
MShipmanPE/ 2 boards / USA *Paid*
Angchuck / 2 boards / Singapore *Paid*
Francois G / 2 boards / USA *Paid*
Asuslover /2 boards /USA *Paid*
astromo / 2 boards / Australia *Paid*
Kay Pirinha / 2 boards / Germany *Paid*
Sixto / 2 boards / USA *Paid*
Tubesguy / 2 boards / USA *Paid*
Hicoco / 2 boards / France
Kokanee / 2 boards / Canada *Paid*
chermann/ 2 boards / Austria *Paid*
twocents/ 2 boards / USA *Paid*
s610adam / 2 boards / USA *Paid*
hochopeper/ 2 boards / Australia
Jlevro / 2 boards / USA *Paid*
nautibuoy / 2 boards / UK *Paid*
invaderzim / 2 boards / USA *Paid*
kp93300/ 2 boards/ Malaysia *Paid*
comicrcc / 2 boards / USA *Paid*

Waiting List:

Legis31/ 2 boards/ usa
Pandpliers/ 2 boards/ USA
DarpMalone / 2 Boards / Canada
turion64 / 2 boards / USA
 
#247
#248
List update:

MaxReboBand / 2 boards / USA
as8912 / 2 boards / USA
ahtllc / 2 boards / USA *Paid Twice!!*
Flamethrower1 /2 boards/ USA *Paid*
Signal Lost / 2 boards / USA *Paid*
diy.tiger / 2 boards / NZ *Paid*
MShipmanPE/ 2 boards / USA *Paid*
Angchuck / 2 boards / Singapore *Paid*
Francois G / 2 boards / USA *Paid*
Asuslover /2 boards /USA *Paid*
astromo / 2 boards / Australia *Paid*
Kay Pirinha / 2 boards / Germany *Paid*
Sixto / 2 boards / USA *Paid*
Tubesguy / 2 boards / USA *Paid*
Hicoco / 2 boards / France *Paid*
Kokanee / 2 boards / Canada *Paid*
chermann/ 2 boards / Austria *Paid*
twocents/ 2 boards / USA *Paid*
s610adam / 2 boards / USA *Paid*
hochopeper/ 2 boards / Australia
Jlevro / 2 boards / USA *Paid*
nautibuoy / 2 boards / UK *Paid*
invaderzim / 2 boards / USA *Paid*
kp93300/ 2 boards/ Malaysia *Paid*
comicrcc / 2 boards / USA *Paid*

Waiting List:

Legis31/ 2 boards/ usa
Pandpliers/ 2 boards/ USA
DarpMalone / 2 Boards / Canada
turion64 / 2 boards / USA
Click to expand...
 
#250
Giveaway list update:

MaxReboBand / 2 boards / USA
as8912 / 2 boards / USA *Cancelled*
ahtllc / 2 boards / USA *Paid Twice!!*
Flamethrower1 /2 boards/ USA *Paid*
Signal Lost / 2 boards / USA *Paid*
diy.tiger / 2 boards / NZ *Paid*
MShipmanPE/ 2 boards / USA *Paid*
Angchuck / 2 boards / Singapore *Paid*
Francois G / 2 boards / USA *Paid*
Asuslover /2 boards /USA *Paid*
astromo / 2 boards / Australia *Paid*
Kay Pirinha / 2 boards / Germany *Paid*
Sixto / 2 boards / USA *Paid*
Tubesguy / 2 boards / USA *Paid*
Hicoco / 2 boards / France *Paid*
Kokanee / 2 boards / Canada *Paid*
chermann/ 2 boards / Austria *Paid*
twocents/ 2 boards / USA *Paid*
s610adam / 2 boards / USA *Paid*
hochopeper/ 2 boards / Australia
Jlevro / 2 boards / USA *Paid*
nautibuoy / 2 boards / UK *Paid*
invaderzim / 2 boards / USA *Paid*
kp93300/ 2 boards/ Malaysia *Paid*
comicrcc / 2 boards / USA *Paid*
Legis31 / 2 boards / USA *moved from waiting list*

Waiting List:

Pandpliers/ 2 boards/ USA
DarpMalone / 2 Boards / Canada
turion64 / 2 boards / USA
Click to expand...

Thank you to everyone for paying promptly for the shipping. I have my work cut out for me to pack these and ship them this weekend.

Btw, Digikey appears to have over 500 of the TDA7293V’s in stock.

https://www.digikey.com/en/products/base-product/stmicroelectronics/497/TDA7293/22627
 
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