Hello,
I am very interested in the freedsp-octavia project mentioned above. I am looking for someone who would be willing to combine an order or someone who has already placed an order and is willing to sell a single unit of the finished device.
Please let me know if anyone can assist.
Thank you.
I am very interested in the freedsp-octavia project mentioned above. I am looking for someone who would be willing to combine an order or someone who has already placed an order and is willing to sell a single unit of the finished device.
Please let me know if anyone can assist.
Thank you.
Hi sirfragles;
there are more people in this thread being interested in a board. We decided to postpone the group buy a bit to make some performance improvements. CyberPit has made some more changes in the last days and I also have some more tests planned butI am currently waiting for my new test pcb.
@CyberPit Do you plan to build/assemble your new revision and test it?
Best Regards,
Ludwig
there are more people in this thread being interested in a board. We decided to postpone the group buy a bit to make some performance improvements. CyberPit has made some more changes in the last days and I also have some more tests planned butI am currently waiting for my new test pcb.
@CyberPit Do you plan to build/assemble your new revision and test it?
Best Regards,
Ludwig
Member
Joined 2018
Hi Ludilu-San,
Well, I have plan to ask my local committee members to join the ver0.33 board evaluation.
The difference between ver0.32 and 0.33 will Analog Series Regulator AMS1117 will change to LM317AG-TN3-R.
It will need to change the schematic design and parts layout, so I would like to update it after the evaluation.
The timeframe will be in September or later...
The change will be like this ...
PCB re-design will take some while. This change will just add a margin of heat dispassion.
CyberPit
Well, I have plan to ask my local committee members to join the ver0.33 board evaluation.
The difference between ver0.32 and 0.33 will Analog Series Regulator AMS1117 will change to LM317AG-TN3-R.
It will need to change the schematic design and parts layout, so I would like to update it after the evaluation.
The timeframe will be in September or later...
The change will be like this ...
PCB re-design will take some while. This change will just add a margin of heat dispassion.
CyberPit
Hi CyberPit-San,
thanks for the information. I suppose you have also not built a v3.0 or v3.1 version yet?
Until september i will also have my testboard tested, so we should have some measurements from it as well.
Ludwig
thanks for the information. I suppose you have also not built a v3.0 or v3.1 version yet?
Until september i will also have my testboard tested, so we should have some measurements from it as well.
Ludwig
Member
Joined 2018
I have not built the v0.3, v0.31, and v0.32 boards yet.
But those circuities are tested with modification on the existing ver0.1 boards.
LM317 has not been tried yet, and that is the reason to need to evaluate it before posting.
CyberPit
Member
Joined 2018
Today I went to Akihabara, where I could buy LM317G.
So, I can evaluate the new design before ordering the ver0.33 PCBA.
CyberPit
So, I can evaluate the new design before ordering the ver0.33 PCBA.
CyberPit
Hi CyberPit-San,
Anyway, good progess!
Ludwig
I asked because I am very interested in seeing the performance with the new output circuit and the pcb layout changes. We will see once a v0.33 is being made.
If only we had places like this over here. A few years ago we had one shop in town that had a few components available, but the company closed all stores. Now the only way is to order online...
Anyway, good progess!
Ludwig
Member
Joined 2018
Well also the same thing in Japan, In Akihabara many parts shops are getting closed and turning to Anime/Figure shops. Only a few shops keep various stocking electric components.
BTW, I evaluated LM317G circuit and I found a mistake in the upside-down value of the resistor divider. 😵
The attached circuit is a fixed PSU for version 0.33.
The resistor 110R was extended parts so I divided it into 100R and 10R.
Perhaps I can post the ver0.33 design and order PCBA soon...
CyberPit
My test board would have arrived yesterday if only I would have managed to order it to my new adress 😖
Now I can resend it or reorder it. I have to see what is cheaper. Good thing the test pcbs were only like 10 USD.
Now I can resend it or reorder it. I have to see what is cheaper. Good thing the test pcbs were only like 10 USD.
Member
Joined 2018
Member
Joined 2018
I uploaded the version 0.33 design files to GitHub.
The main change point is the series voltage regulator. (LM317)
Some trace patterns had changed.
I will look for volunteers to join the evaluation. Among the local committee members.
So this design will be built and evaluated soon.
CyberPit
The main change point is the series voltage regulator. (LM317)
Some trace patterns had changed.
I will look for volunteers to join the evaluation. Among the local committee members.
So this design will be built and evaluated soon.
CyberPit
FYI: I tried to meassure the output impedance of the DAC. My calculations resulted to about 17ohm. (I measured the voltage without load and with 1k load and calcualted the internal resistance)
Btw, my test PCBs arrived. I only wait for some more parts to fully assemble the PCB. I guess by the end of next week I will have some results.
Member
Joined 2018
I had ordered 10pcs version 0.33 boards. And it will be evaluated soon...
After evaluated this board, I will change the design of RCA-pin Jacks to RCJ-2223. It has a upside down L/R layout but it's easy to get over the world.
CyberPIt
After evaluated this board, I will change the design of RCA-pin Jacks to RCJ-2223. It has a upside down L/R layout but it's easy to get over the world.
CyberPIt
Very nice,
I am very excited and looking forward to the first measurements.
Ludwig
I am very excited and looking forward to the first measurements.
Ludwig
Thankyou CyberPit-San and Ludilu for your persistence with enhancing this very worthwhile project. It is really exciting and an amazing contribution to the DIY community. Many of us await the measurements with great interest! 🙂
Last edited by a moderator:
Hi everyone,
the first measurement with the test-board is in.
THD is definitly better, but my noise floor is a bit worse. This, however, is very likely due to the setup with flying cables...
So THD-N is similiar to before and THD is better. Maybe I can improve my setup a bit to get a better noise floor.
With THD of -98.7 we are probably at the spec of the DAC. I guess this will not get much better.
I'll keep you udpated if manage to get some more results.
BR Ludwig
the first measurement with the test-board is in.
THD is definitly better, but my noise floor is a bit worse. This, however, is very likely due to the setup with flying cables...
So THD-N is similiar to before and THD is better. Maybe I can improve my setup a bit to get a better noise floor.
With THD of -98.7 we are probably at the spec of the DAC. I guess this will not get much better.
I'll keep you udpated if manage to get some more results.
BR Ludwig
Attachments
Member
Joined 2018
My FreeDSP OCTAVIA PCBA board is now on my way to my residence.
Maybe a couple of days will arrive...
Oops!
ADAU1466 is now in stock at JLPCB PCBA parts library
I missed catching up on this chance
CyberPit
Maybe a couple of days will arrive...
Oops!
ADAU1466 is now in stock at JLPCB PCBA parts library
I missed catching up on this chance
CyberPit