A New Take on the Classic Pass Labs D1 with an ESS Dac

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I will use the AKM MCU unit for register setting and volume/input control of the dac (seen on the bottom left of the above pic, with the volume knob on it, its connected to my mac via an RS232->USB adapter and controlled using terminal (snapshot below)), but the display and monitor/control will be based on a network of 1mW xBee wifi modules and a beaglebone.

the ackodac MCU already has RS232 and non volatile memory for saving functions, plus dip switches and rotary controls; which means all functions can be controlled with both tactile controls, or over USB/wifi/ipad but the beaglebone will allow it to be somewhat antonymous without needing to be connected to my Mac the whole time. i'm treating the whole system of dacs and multiple amplifiers as one system under the control of the beaglebone, so that sequenced start up/shutdown, various voltages and temperatures can be monitored and influenced.

we will start by working with off the shelf modules connected in a network, but ideally I would like to spin a PCB
 

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qusp was about to email you but since it seems almost on topic given where we're at now with enclosures. I've been working my way through the old posts in this thread ... hard yakka I tell ya.

The final layout for component arrangement is essentially this here, right?


Given these power supply requirements for ess dacs you've posted back in Sept last year in the build thread here and I guess that info is interesting to bigpandahk given the shunt reg discussion in Ian's FIFO thread today too.

So my recollection of the last time I saw your acko+NTD1 enclosure is a bit hazy so I've been thinking through how I would go about arranging the two so I could work out just how big an enclosure I really would need.

The below assumes stereo setup, I'm not crazy enough to contemplate multichannel NTD1.

My question is would it be logical/feasible to use the acko where the shunt regs for the more critical supplies AVCC_L/AVCC_R & VDD_L/VDD_R are used but since they are connecting to 'short' edge of the ackodac pcb they hang over the edges of the NTD1 pcb and don't interfere with NTD1 PSU components. If you were to use an external MCLK rather than the onboard clock (say Ian's FIFO clock) then you don't need to connect any supply to VOSC connection right? That would leave only the DVCC_B power supply needing to get around the issues with the NTD1 onboard PSU components. Would one of those nice looking BLUE stick regulators be suitable for that supply? I was also contemplating 4 x salas shunt regs for the supplies to AVCC_L/AVCC_R & VDD_L/VDD_R actually.

I'm just trying to visualise a layout for how the ackodac AKD12 could be mounted and still use the NTD1 PSU.

For a stereo configuration then you won't need a metric acre of room for the ackodac, maybe just half an acre and some space to place FIFO and a USB interface board with supplies for each.
 
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The blue sticks are perfectly fine to run straight to the dac board for top and bottom ring supplies.

Edit: The only advantages of running the blue stick supply thru the usual acko regs in those positions are the CMC and big *** ferrite bead... which is only a requirement if the blue stick is in another case and then 2 feet away with an unshielded umbilical. IMO disclaimers of course.
 
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yep, you can use the blue stick regs for the less than critical supplies, just doesnt stack as neatly and you have to sequence them all. the acko MCU needs to be powered up first to manage the register sequence. the current requirements posted are based on using an 80MHz clock, you can buy the dac without the clock even fitted, which is what I would recommend you do, there is a u.fl header under the XO position. ideally with the ackodac you should either mount the NTD1 to a suitably thick floor, then the dac + fifo clock module and then the regs and USB module on a platform above, or invert the whole thing, use a heatsink like mine, with the shunt regs on the floor sinking to the floor, then the dac mounted on them, then the NTD1 + heatsink mounted above them, inverted with the heatsink fins pointing up and visually obscuring all your hard work for neat layout. this could be gotten around by having the enclosure designed so you can see in at floor level.

personally i dont really see the point of using shunts for such steady supplies, you can get steady low noise regs in much smaller packages. for very dynamic loads they are great, but none of the pins you mention are that.
which is only a requirement if the blue stick is in another case and then 2 feet away with an unshielded umbilical.
which is what i'm doing, maybe i'll go shielded, but I actually dont think your average screened shield does that much good. the choke also means the whole dac can float and I can tell you after feeding jh13 directly from the bal-bal wire, directly connected to the dac; is a pretty surreal experience. no music playing, full volume, not a whimper of noise, complete blackness....

also not having AC wires going anywhere near the dac makes routing signal (of all sorts) a lot less of a pita
 
yes, in the sense that if you use a dedicated secondary for each one they are floating. maybe I misunderstand and have to look it up, but for some reason I thought common mode chokes were like transformers and thats how they act on common mode noise? maybe its just the appearance. actually maybe i'm thinking of inductors.

ninja.... hiiaaaya!!

those who call me expert can now see i'm learning just as you. no background in this stuff, I learn as I go. i'm off to do some reading
 
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yeah I was about to add 'for DC' but you beat me to it. i've never really had cause to read up on them but I will now. starting with the simplified circuit. dont play with toobs or lightbulbs (sit reference for those watching) so havent really had any other contact with them other than on the acko regs

anyway....... 100W+ 4 channel dac..hmmmmm
 
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Use the 2 x LM317/337 bipolar reg pairs to power the NTD1. 5V reg left unpopulated or used to power XMOS USB interface. DAC power supplies separate but perhaps not use acko's AKR for the supplies that are on the same side of the board as the NTD1 regs, just to be sure they're clear of that part of the NTD1 circuit and minimal distance from DAC output to NTD1 input.
 
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my PSU is snapped off, I never bothered to try it connected with the ackodac, I still use the supply, but its mounted down on the floor, with the IV up on the sink. if you will be using a sink and not the chassis floor, you can mount the caps, regulators and heatsinks from underneath but reversed so the pinout still matches up. with the PSU section overhanging the heatsink. then you can do what you like. there are many ways to achieve it, myself I wouldnt be making any plans till youve built the thing up and used it, then design the case around it, not the other way around
 
If I'm not too late, another one for me
1. cersepn x 1
2. icewall x 2
3. pmchoong x 1
4. qusp x 1 this is tentative mate, but wanted to make sure my name was down
5. regal
6. randytsuch x 1
7. LK x1
8. greyrab x1
9. alexcount x1
10. adelias x1
11. Coolhead x1 + fets
12. Emphrygian x 1
13. tranhieu x 1
14. crazyfrog x 1
15. woresseo x 2
16. Algar_emi x 1
17. ggetzoff x 1
18. syklab x1 + fets
19. Magsy x 1
20. Vitalica x2 + fets
21. Pinnocchio x 1
22. hochopeper x 1
23. neb001 x1 + fets
24. bigpandahk x 2 + fets
25, Jean-Charles X1 +fets
26,iancanada X1 + fets
27. lll X1+fets
28. analog_sa x2 + fets x 2 (shipping to US)[/QUOTE]
29. savvas + fets
 
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