WesionTEK Khadas "Tone Board" successfully integrated with agdr Audio Super CMoy. Full build can be viewed HERE.
An externally hosted image should be here but it was not working when we last tested it.
Nicely done man!
I'd never heard of that DAC before, but it looks like it's got some solid specs.
Did you decide to use two USB cables instead of piggy back the DAC off the same one as as the Super CMoy?
Thank you. Yes, since the first usb cable is power only. The second cable is both data and power.
0.005 ohm typical On resistance optical-mosfet solid state relay:
The COTO CT128 MOSFET relay mentioned is 0.05 ohms max, 0.033 ohms typical connected in AC mode, but 0.025 ohms max/0.016 ohms typical with outputs connected parallel in DC mode, DIP-6. Also available in SMD-6 package. About $7.
Increased current by connecting outputs from one device in parallel
https://cotorelay.com/wp-content/uploads/2014/05/CotoMOS-IncreasingCurrentCapacity.pdf
Parallel operation of multiple CS128/CT128 devices:
https://cotorelay.com/wp-content/uploads/2014/05/AmpacityCS128_ProductSheet.pdf
App note AN 1604-1 on Parallel operation of multiple CS128/CT128 devices:
https://cotorelay.com/wp-content/uploads/2018/05/Ampacity-AppNote.pdf
A less expensive alternative with even lower output On resistance is the Toshiba TLP3543.
0.04 ohm max, 0.02 ohm typical in AC “A” configuration but 0.005 ohm typical with outputs connected in parallel DC “C” configuration, SMD-6 Gull wing ($4) or DIP-6 ($5)
These output On resistance values are generally listed at full maximum current (Amps). Are they much different at low (mA) currents?
The COTO CT128 MOSFET relay mentioned is 0.05 ohms max, 0.033 ohms typical connected in AC mode, but 0.025 ohms max/0.016 ohms typical with outputs connected parallel in DC mode, DIP-6. Also available in SMD-6 package. About $7.
Increased current by connecting outputs from one device in parallel
https://cotorelay.com/wp-content/uploads/2014/05/CotoMOS-IncreasingCurrentCapacity.pdf
Parallel operation of multiple CS128/CT128 devices:
https://cotorelay.com/wp-content/uploads/2014/05/AmpacityCS128_ProductSheet.pdf
App note AN 1604-1 on Parallel operation of multiple CS128/CT128 devices:
https://cotorelay.com/wp-content/uploads/2018/05/Ampacity-AppNote.pdf
A less expensive alternative with even lower output On resistance is the Toshiba TLP3543.
0.04 ohm max, 0.02 ohm typical in AC “A” configuration but 0.005 ohm typical with outputs connected in parallel DC “C” configuration, SMD-6 Gull wing ($4) or DIP-6 ($5)
These output On resistance values are generally listed at full maximum current (Amps). Are they much different at low (mA) currents?
The one in the middle is the single chip version. Its IC2.
The outside pcbs are the dual chip version. Notice the double sets of pads for the 1688's.
Those small 1688's are a challenge to solder!
I have an original prototype from back in the beginning that still works, its doesn't have the muting relay but works fine....just turn down the volume and turn on then plug in your headphones...works great.
I even have used it with the cans plugged in and the small click or pop is really very small its not an issue.
That said AGDR is a perfectionist and had to insert the relay in it...
Alex
The outside pcbs are the dual chip version. Notice the double sets of pads for the 1688's.
Those small 1688's are a challenge to solder!
I have an original prototype from back in the beginning that still works, its doesn't have the muting relay but works fine....just turn down the volume and turn on then plug in your headphones...works great.
I even have used it with the cans plugged in and the small click or pop is really very small its not an issue.
That said AGDR is a perfectionist and had to insert the relay in it...
Alex
Glad to see all the continued interest in this project! 
I've only built one thus far, and when I get a chance I'll post build photos. But I use it everyday for audio editing and can testify to it's quality and reliability. Just super clean/neutral gain and basically nonexistent noise floor.
I know at this time AGDR isn't able to devote more time to this project, which I completely understand. But I've wondered if he might be open to making his PCBs available through either Tindie or OSH Park so that more people could easily join in on this project?
I've only built one thus far, and when I get a chance I'll post build photos. But I use it everyday for audio editing and can testify to it's quality and reliability. Just super clean/neutral gain and basically nonexistent noise floor.
I know at this time AGDR isn't able to devote more time to this project, which I completely understand. But I've wondered if he might be open to making his PCBs available through either Tindie or OSH Park so that more people could easily join in on this project?
![WP_20190402_15_19_46_Pro (2)[3791].jpg](/community/data/attachments/670/670197-345b11cefc57e0aa06e7da720ac6ab50.jpg)
Thanks for the reply!
I saw those files, but they're only png image files and I'm not currently versed how to convert them to Gerber (or other) files most of those fabrication houses use.
It's not much of a concern for myself as I was able to get parts straight from AGDR. I'm more thinking it would be great if there was a Tindie or OSH Park setup to where AGDR would receive a percentage of the sales. I know he put a tremendous amount of work and time into the project and I'd love to see the DIY community able to give back
I love your pre-assembly pile, Alex!
No gerbers guys, but I do have PC boards and assembled TPS boards. PM me. Several reasons for not releasing the Gerbers. One from unfortunate past experience is they instantly become products for sale in China.
Hey Alex discovered the 5% version of the 3.3uF film coupling capacitor is finally back in stock at Mouser! Part #505-MKS2B043301HJSSD . Those are extremely rare (the 10% is much more common). $1.13 each at Mouser, 4800 in stock right now, get 'em while u can!
Alex also discovered that C10 got caught up in TDK's MLCC part number switch-over. A current part is 810-FA22X7R1H33500 at Mouser.
No gerbers guys, but I do have PC boards and assembled TPS boards. PM me. Several reasons for not releasing the Gerbers. One from unfortunate past experience is they instantly become products for sale in China.
Hey Alex discovered the 5% version of the 3.3uF film coupling capacitor is finally back in stock at Mouser! Part #505-MKS2B043301HJSSD . Those are extremely rare (the 10% is much more common). $1.13 each at Mouser, 4800 in stock right now, get 'em while u can!
Alex also discovered that C10 got caught up in TDK's MLCC part number switch-over. A current part is 810-FA22X7R1H33500 at Mouser.
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