This thread is to organize the logistics of the subject amplifier PCB giveaway. Technical details of the amp can be found here:
Xmas Amp - Dibya's TDA7293 by Jhofland
For technical discussions please use the other thread (above link).
Schematics here:
https://www.diyaudio.com/forums/att...7293-jhofland-tda7293_-schematic_12_06_20-pdf
Photo of actual PCB:
The amp has been fully tested and verified by Vunce and myself. We have a few minor edits for Jhofland to include in the final layout. The full amp schematics, BOM, and Gerber files are freely available for anyone to make their own boards. But this thread is for those who signed up in the other thread to get a free board for the cost of shipping.
Vunce’s verification build:
My verification build:
Closeup of the assembled boards:
Edit Jan 18, 2021: Latest measurements show that this amp has excellent performance with low THD and a natural non-fatiguing harmonic distortion proifile. Here is a loud playing 6.4Wrms into 10ohms:
Very loud 40Wrms into 10ohms:
It’s a great sounding amp! Easy to build and works very well. I recommend either 200VA to 250VA 25v trafo (either dual secondaries or center tap) or dual mono 100VA to 200VA 25v trafos. Nominal voltage is +/-35v and as high as +/-37v for design as presented with LM317/337L regulators. For 50v rails, use the zener diode mod in the other thread and big heatsink. The +/-15v voltages are needed for the DC servo.
To keep things simple, folks who are on the current list will send the shipping funds via PayPal and please include your DIYA screen name and your shipping address name and address in the PayPal payment. To keep things simple I will use a fixed shipping costs as follows.
Amounts are in USD and covers cost of PayPal fees, bubble padded mailer envelopes, and shipping labels. Cost for shipping will be $5 in USA, $8 in Canada, and $15 everywhere else. Boards will be sent via USPS First Class mail. No tracking and no insurance to keep costs low. As I have mentioned, you can also download the Gerbers linked in other thread and have your own boards made for not much money if you don’t want to participate in the giveaway.
I will compare your DIYA screen name in the PayPal payment to the list below to track the number of people. I am giving away 25 sets of two boards, they will be 1.6mm thick with 2oz copper and green solder mask.
Please send your PayPal funds to my address at xrk971 “at” rfasystems “dot” com.
Don’t forget to include your screen name and address.
Thanks, and happy belated Xmas and New Year!
A big thanks to Dibya for the inspiration and original design features and thanks to Jhofland for the final design and layout. Big thanks to Vunce for verifying the build.
Here is the current giveaway list:
Xmas Amp - Dibya's TDA7293 by Jhofland
For technical discussions please use the other thread (above link).
Schematics here:
https://www.diyaudio.com/forums/att...7293-jhofland-tda7293_-schematic_12_06_20-pdf
Photo of actual PCB:
The amp has been fully tested and verified by Vunce and myself. We have a few minor edits for Jhofland to include in the final layout. The full amp schematics, BOM, and Gerber files are freely available for anyone to make their own boards. But this thread is for those who signed up in the other thread to get a free board for the cost of shipping.
Vunce’s verification build:
My verification build:
Closeup of the assembled boards:
Edit Jan 18, 2021: Latest measurements show that this amp has excellent performance with low THD and a natural non-fatiguing harmonic distortion proifile. Here is a loud playing 6.4Wrms into 10ohms:
Very loud 40Wrms into 10ohms:
It’s a great sounding amp! Easy to build and works very well. I recommend either 200VA to 250VA 25v trafo (either dual secondaries or center tap) or dual mono 100VA to 200VA 25v trafos. Nominal voltage is +/-35v and as high as +/-37v for design as presented with LM317/337L regulators. For 50v rails, use the zener diode mod in the other thread and big heatsink. The +/-15v voltages are needed for the DC servo.
To keep things simple, folks who are on the current list will send the shipping funds via PayPal and please include your DIYA screen name and your shipping address name and address in the PayPal payment. To keep things simple I will use a fixed shipping costs as follows.
Amounts are in USD and covers cost of PayPal fees, bubble padded mailer envelopes, and shipping labels. Cost for shipping will be $5 in USA, $8 in Canada, and $15 everywhere else. Boards will be sent via USPS First Class mail. No tracking and no insurance to keep costs low. As I have mentioned, you can also download the Gerbers linked in other thread and have your own boards made for not much money if you don’t want to participate in the giveaway.
I will compare your DIYA screen name in the PayPal payment to the list below to track the number of people. I am giving away 25 sets of two boards, they will be 1.6mm thick with 2oz copper and green solder mask.
Please send your PayPal funds to my address at xrk971 “at” rfasystems “dot” com.
Don’t forget to include your screen name and address.
Thanks, and happy belated Xmas and New Year!
A big thanks to Dibya for the inspiration and original design features and thanks to Jhofland for the final design and layout. Big thanks to Vunce for verifying the build.
Here is the current giveaway list:
Attachments
Last edited:
Thank you,
Jlevro, Astromo, and Nautibuoy!
The final layout Gerbers have just been completed and revised schematics abs BOM will be forthcoming. Just addition of 100k resistor to ground to keep the input connector from floating without anything connected. Mounting holes electrically isolated except top right one which has a GLB (ground loop breaker). Larger optional Wima 4.7uF 250v MKP for the input cap. So the board grew 7mm wider.
Jlevro, Astromo, and Nautibuoy!
The final layout Gerbers have just been completed and revised schematics abs BOM will be forthcoming. Just addition of 100k resistor to ground to keep the input connector from floating without anything connected. Mounting holes electrically isolated except top right one which has a GLB (ground loop breaker). Larger optional Wima 4.7uF 250v MKP for the input cap. So the board grew 7mm wider.
Here is the final layout with all corrections applied.
1. Isolate the mounting bolt pads from the ground plane, except the top right bolt is connected to the ground via a ground loop breaker (opposed diodes, 10R resistor, and 100nF film cap, all in parallel)
2. Add third set of optional pads for Wima 4.7uF 250v MKP film cap at C1
3. Add 100k resistor to input pin upstream of input coupling cap.
4. Update BOM to show 47k5 resistor for R15 to allow DC servo to work properly.
New and final board layout (107mm x 65mm):
Schematic here.
BOM here.
1. Isolate the mounting bolt pads from the ground plane, except the top right bolt is connected to the ground via a ground loop breaker (opposed diodes, 10R resistor, and 100nF film cap, all in parallel)
2. Add third set of optional pads for Wima 4.7uF 250v MKP film cap at C1
3. Add 100k resistor to input pin upstream of input coupling cap.
4. Update BOM to show 47k5 resistor for R15 to allow DC servo to work properly.
New and final board layout (107mm x 65mm):
Schematic here.
BOM here.
Thank you X (and others) for all the effort and a great project.
Payment sent, but this time PayPal did not give me the "Friend" option. If you incurred extra costs on your side, let me know please. I was actually hoping we could use the Etsy route as I actually wanted some All Cee boards at the same time, but can get that later.
Payment sent, but this time PayPal did not give me the "Friend" option. If you incurred extra costs on your side, let me know please. I was actually hoping we could use the Etsy route as I actually wanted some All Cee boards at the same time, but can get that later.
The boards have just been ordered and so I should have them in maybe 10 days. The little change to add the 4.7uF cap increased the board maximal dimension from 100mm to 107mm, exceeding the magic 100mm “budget” board limit. Some of you have donated to me more than the recommend amount, and it’s really not a big cost, all things considered.
Great to see so many people signed up for this project. I just hope you try and build the amp. It really is an easy and enjoyable amp to solder. All the parts fit and go where they are supposed to per the BOM and schematic.
Great to see so many people signed up for this project. I just hope you try and build the amp. It really is an easy and enjoyable amp to solder. All the parts fit and go where they are supposed to per the BOM and schematic.
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