Xmas Amp - Dibya's TDA7293 by Jhofland

[nautibuoy]

Rule #2?

 

[liva]

Sorry guys but i realized i have way to many projects already ,
Please kindly remove my name from the list .
Thanks

 

[xrk971]

No worries, there were a few who were asking if spots available.

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 * cancelled *
Hicoco / 2 boards / France
Liva / 2 boards / Canada * cancelled *
Kokanee / 2 boards / Canada
chermann/ 2 boards / Austria
twocents/ 2 boards / USA
s610adam / 2 boards / USA
hochopeper/ 2 boards / Australia
1883 / 2 boards / USA *Canvelled*
Jlevro / 2 boards / USA
nautibuoy / 2 boards / UK

Whoever needs boards, add your name. Plenty available now. 3 more sets available now.

 

[invaderzim]

yay! I thought I'd missed out. I'm a big fan of the 7293 chips.

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 * cancelled *
Hicoco / 2 boards / France
Liva / 2 boards / Canada * cancelled *
Kokanee / 2 boards / Canada
chermann/ 2 boards / Austria
twocents/ 2 boards / USA
s610adam / 2 boards / USA
hochopeper/ 2 boards / Australia
1883 / 2 boards / USA *Canvelled*
Jlevro / 2 boards / USA
nautibuoy / 2 boards / UK
invaderzim / 2 boards / USA

 

[kp93300]

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 * cancelled *
Hicoco / 2 boards / France
Liva / 2 boards / Canada * cancelled *
Kokanee / 2 boards / Canada
chermann/ 2 boards / Austria
twocents/ 2 boards / USA
s610adam / 2 boards / USA
hochopeper/ 2 boards / Australia
1883 / 2 boards / USA *Canvelled*
Jlevro / 2 boards / USA
nautibuoy / 2 boards / UK
invaderzim / 2 boards / USA
kp93300/ 2 boards/ Malaysia

 

[xrk971]

Great to see more interest.

We have good news to report. After some debugging and Jhofland ran some simulations of the DC servo, we found that by replacing R115 with a 47k ohm resistor, the DC servo works now with less than 5mV offset. So now, we have eliminated the electrolytic cap in the negative feedback path. Hopefully this translates to deeper bass.

 

[comicrcc]

I would like to get a pair of amps as well if available. 65 and love to keep my mind active building amps. Thanks very much.

 

[legis31]

Waiting list addition

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 * cancelled *
Hicoco / 2 boards / France
Liva / 2 boards / Canada * cancelled *
Kokanee / 2 boards / Canada
chermann/ 2 boards / Austria
twocents/ 2 boards / USA
s610adam / 2 boards / USA
hochopeper/ 2 boards / Australia
1883 / 2 boards / USA *Canvelled*
Jlevro / 2 boards / USA
nautibuoy / 2 boards / UK
invaderzim / 2 boards / USA
kp93300/ 2 boards/ Malaysia
Legis31/ 2 boards/ usa

 

[Pandpliers]

Waiting list addition.

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 * cancelled *
Hicoco / 2 boards / France
Liva / 2 boards / Canada * cancelled *
Kokanee / 2 boards / Canada
chermann/ 2 boards / Austria
twocents/ 2 boards / USA
s610adam / 2 boards / USA
hochopeper/ 2 boards / Australia
1883 / 2 boards / USA *Canvelled*
Jlevro / 2 boards / USA
nautibuoy / 2 boards / UK
invaderzim / 2 boards / USA
kp93300/ 2 boards/ Malaysia
Legis31/ 2 boards/ usa
Panellists/ 2 boards/ USA

 

[Pandpliers]

Please ignore Panelists. Typo by auto spell. I apologize. Should be..

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 * cancelled *
Hicoco / 2 boards / France
Liva / 2 boards / Canada * cancelled *
Kokanee / 2 boards / Canada
chermann/ 2 boards / Austria
twocents/ 2 boards / USA
s610adam / 2 boards / USA
hochopeper/ 2 boards / Australia
1883 / 2 boards / USA *Canvelled*
Jlevro / 2 boards / USA
nautibuoy / 2 boards / UK
invaderzim / 2 boards / USA
kp93300/ 2 boards/ Malaysia
Legis31/ 2 boards/ usa
Pandpliers/ 2 boards/ USA

 

[nautibuoy]

I think this is how it looks:

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 * cancelled *
Hicoco / 2 boards / France
Liva / 2 boards / Canada * cancelled *
Kokanee / 2 boards / Canada
chermann/ 2 boards / Austria
twocents/ 2 boards / USA
s610adam / 2 boards / USA
hochopeper/ 2 boards / Australia
1883 / 2 boards / USA *Canvelled*
Jlevro / 2 boards / USA
nautibuoy / 2 boards / UK
invaderzim / 2 boards / USA
kp93300/ 2 boards/ Malaysia
comicrcc / 2 boards / USA

Waiting List:

Legis31/ 2 boards/ usa
Pandpliers/ 2 boards/ USA

 

[DarpMalone]

I think this is how it looks:

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 * cancelled *
Hicoco / 2 boards / France
Liva / 2 boards / Canada * cancelled *
Kokanee / 2 boards / Canada
chermann/ 2 boards / Austria
twocents/ 2 boards / USA
s610adam / 2 boards / USA
hochopeper/ 2 boards / Australia
1883 / 2 boards / USA *Canvelled*
Jlevro / 2 boards / USA
nautibuoy / 2 boards / UK
invaderzim / 2 boards / USA
kp93300/ 2 boards/ Malaysia
comicrcc / 2 boards / USA

Waiting List:

Legis31/ 2 boards/ usa
Pandpliers/ 2 boards/ USA
DarpMalone / 2 Boards / Canada

 

[xrk971]

More great progress from Vunce. The verification build is now playing in stereo in the donor chassis. Source is AD1862 DAC, Yarra with ACP+ as preamp, TDA7293 amp with All Cee’s PSU loaded with 4x 10,000uF caps and 300w 25v trafo, and 10F/RS225 FAST TL’s speakers. So far everything plays and sounds quiet (no hum). One note: the mounting screws for the TDA7293 boards need to be insulated as the ground plane currently extends all the way to the edge. One of them has a ground loop breaker but the others do not. We will need to modify the final layout to have the remaining 3 holes electrically isolated from ground to avoid hum and ground loops.

So the only required mod for now with respect the components is the use a value from 10k to 47k for R15 to get the DC servo to work properly. With 47k we are getting about 4mV DC offset. The optional zener diode opamp power supply mod has been tested and works. Only needed if you plan to use power supplies > 40Vdc.

 

[r_jik45]

Are some parts of the power supply connected to the heatsink too?

 

[Vunce]

Only the GBJ2510 bridge rectifier touches the heatsink, but it barely gets warm. Probably can be left in “free air”.

 

[xrk971]

I just finished building my Xmas TDA7293 amp. I still need to drill and tap an M3 screw thread on the CPU cooler heaatsink. Will do that tomorrow and connect to my +/-37.4v PSU. I am using some 5uF polycarbonate input caps. I am using the DC servo with a 47k value for R15 (as tested by Vunce).

 

[chermann]

maybe i missed that information..sorry..why is the C28 shorted/not used?

 

[twocents]

Nice X! A lot sexier (with those fancy green inductors) than Vunce's build, which seem to be missing some components. 😀
Waiting in anticipation for listening impressions...

 

[Kay Pirinha]

maybe i missed that information..sorry..why is the C28 shorted/not used?

It isn't C28 that has been omitted and shorted, but C2. As yet been said previously, this capacitor in the NFB path isn't necessary with a properly working DC offset servo. Anyway, C17 could have been omitted also.

Best regards!

 

[Vunce]

Nice X! A lot sexier (with those fancy green inductors) than Vunce's build, which seem to be missing some components. 😀
Waiting in anticipation for listening impressions...

Yeah, my inductors are not up to my standards, I had to re-form existing pieces.
All parts necessary are populated on my boards, the “missing” pieces are because the HV dc servo psu is configured differently than using the LM317/337 regulators.