FreeDSP Classic SMD A/B plus II is on Development

[CyberPit]

Hi Folks!
Now I'm developing a new version of "FreeDSP Classic SMD A/B" which is named "FreeDSP Classic SMD A/B plus II"
This board has two additional features. Embedded PCM5102 for DIG6/7 output plus Ez-USB Fx2LP board slot for embedded FreeUSBi .
The other features keep the concept as FreeDSP Classic SMD A/B.

• Dual configuration EEPROMs for program A/B selection.
• 2V r.m.s. Unity Gain I/O
• Power ON/OFF and Reset muting.
• I6S(3 times I2S) buffered digital output Header
• I2S Digital Input
• Single DC12V power supply.

The current version board had PCBA done at JLPCB. Design information will be updated soon.


CyberPit

 

[weissi]

I would be interested in the other board you've showed in the other thread. From what I saw, it accomodates the ADAU1452/-66 chinese boards.
Any chance to get the gerber files?
'cause I think having the boards shipped from Japan to Austria would be verrrry expensive...

Thank you & Best regards!

 

[ErikdeBest]

Subscribed!

 

[CyberPit]

Hi Guys,


Okay, I will upload a little bit newer them and related files at the cheap aliexpress/ebay ADAU1452 development boards thread later. (That place will fit more than here...)


CyberPit

 

[CyberPit]

I had committed my design files to Git-Hub.
GitHub - CyberPit/FreeDSP_Classic_SMD_AB_plus-II: An extended version of FreeDSP Classic SMD A/B


SMT related files also committed. So it's easy to build if you want.





Enjoy!


CyberPit

 

[mikec24]

Hi all

Just downloaded the project files for this and I am interested in building the it, although there has been no activity since October last year! Is this still actively being developed or is it considered finished?


One query, the project files describe the USBi daughter board with an IDC connector whereas the photograph in this thread shows a USB micro connector, is a separate USBi programmer required or is all that is required a USB cable to the PC running SigmaStudio?

 

[CyberPit]

Design already evaluated and released

Hello mkec24-San,

Well, I'm asking to freedsp.cc to add on the list this design...

This version 0.2 design is my Design-Release. Previous version 0.1 board was evaluated by eight people. Fixing/changes between 0.1 and 0.2 are as follows...
(1)Change the Reset pull-up resistor R49 value from 47k to 4.7k
(2)Tie-down PCM5102A pin12 SCK to GND (Invoke PLL for 192kHz fs)
The rest of part is exactly the same as version 0.1, so I believe there's no changes ordered.


Embedded FreeUSBi Slot:
A daughter-board (Ez-USB FX2LP board) is completely the same as original FreeUSBi. One of compatible board image had attached below. You can use ADI's standard IDC-10P Cable from USBi or USB-mini cable even the cape-board installed. (Please use Only-One at a time)


CyberPit

 

[mikec24]

Thank you Cyberpit for clarifying my queries. I have a lifetime in technology but am new to DSP's. My project is to refurbish my 4 way TL's that I built some 43 years ago and are still in daily use (B J Webb Audio Amateur issue 1 1975). My requirement, If I make them fully active, is to have 1in x 4out, for each enclosure, assuming that is possible with the ADAU1701? This I am researching at the moment

 

[CyberPit]

Hi mikec24-San,
I've read that article.
Wow, I was impressed your made TL system in '75. 😱
I tried TL system only four years ago...

My requirement, If I make them fully active, is to have 1in x 4out, for each enclosure, assuming that is possible with the ADAU1701?

Well, you can easily to add 1-3 more PCM5102 output such as ready made DAC board(s) connect to the I2S output header.
SA9227 PCM5102 TDA1308 PCM5102A DAC Decoder I2S Player 32bit Amplifier Board | eBay
I believe, ADAU1701 embedded ADC/DAC has enough quality for the most of audio applications. 96kHz DSP processing with time alignment will be able to implement with this FreeDSP board.

 

[mikec24]

Thank you Cyberpit for that information


My plan would be to assemble two boards, one for each enclosure and so the onboard 4x o/p would, I hope, suffice. Each enclosure would then have power amps, power supplies in an enclosure that the speaker will stand on. Signal either via co-ax, balanced or eventually wi-fi
Looking at the data sheet for the ADAU1701, the ADC's & the DAC's have THD+N figures of 83&90db respectively so around <0.01%. Have you carried out any tests for your design?

The TL's were the best of the best back then and I still think that even with today's drivers, that they will be hard to beat, that is why I am so keen to bring them into the 21st century. I have also built and am now testing, the Blomley class B power amp that may well be part of this upgrade

 

[CyberPit]

Hi mikec24-San,
Here's FreeDSP Classic SMD A/B plus2's actual measured overall ADAU1701 embedded ADC-->DAC through performance...


[Fs=48kHz]

Overall THD=0.0036%, THD+N=0.032%(48kBW)
Input Short relative to clipping level S/N=88.0dB(22kBW)


[Fs=96kHz]

Overall THD=0.0058%(22kBW)
Input Short relative to clipping level S/N=86.2B(22kBW)

 

[mikec24]

Thank you for that information CyberPit

I have had a look at Jclpcb prices for a board populated based on your BOM/CPL and they are reasonable. Looks like I will be ordering in the near future

 

[Alex Madsen]

CyberPit, I like the design. I just ordered and received quantity 5 from JLC. Still need to populate the remaining parts.

I have converted the parts list/Bill of Material for both North American distribution (Digikey) and Aisain distibution (LCSC).

Alex

 

[CyberPit]

Hi mikec24-San, Alex-San,
I'm glad to hear from you, Let's enjoy DIY activities!


CyberPit

 

[maisdoidoainda]

Someone here want to group buy with me some populated boards from Jclpcb?
5 Is to much for me hahaha

I'll keep 2 or 3