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

[qusp]

I made a typo above too, had 2 x 25VA secondaries on the brain and typed 25VAC instead of 45VAC.

yeah the molex connectors are a minefield, you can pay stupid money for them, especially in small numbers, we really should have done a GB on them. I got some different and even pricier ones with machined sockets instead of stamped. but the ones you have linked are indeed a bit expensive at digikey, cheaper at mouser.

the main thing to watch if you dont plan on plugging and unplugging a lot is the thickness of the gold plating, this adds a lot to the price if you go for the thicker plate. I personally just buy the expensive sockets, but make my own male pins with hard annealed sterling silver wire that i have heaps of. if anyone would like some of the silver let me know and i'll send with your board. I even have some hard annealed solid 9ct yellow and white gold I was thinking of using for the main outputs lol just because I can. and really actually works out cheaper than the molex haha

[merlin el mago]

I haven't clear the heatsink for the I/V (not regulators), could you suggest anything I can buy in Digi-Key, Mouser, RS or Farnell?

[qusp]

hmm, I dont know about the large heatsink catalogue at DK or mouser. the only way this board can be mounted really is with the sink under the board and it must really be at least 0.60C for 80 degree rise and preferably better. very quiet here, nobody else has done any building? I have done all the SMD soldering for 5 boards and nobody else??

need to get these parts porn pics up, again my day flew by without getting that done and now everything is here pretty much. still waiting on my heatsinks as the drilling pattern for mounting holes was only just finalized, hopefully conrad can still get it done before their break. otherwise I will have to come up with another heatsink for matching if not and really that would be fine, because there is little chance of me being finished matching before then anyway.

one thing I will say WRT heat is that you will not be able to get away with using the floor of a small case, you will make a nice little toaster oven this way. if using the bottom of a case as the sink, it needs to be a biggish case and well ventilated.

[Horio]

I'm surprised how quiet it has been as well. I am going to do the SMD soldering this weekend. I'm planning to use the base of my case to spread the head over to two conrad sinks mounted vertically (much like OPC had shown in a sketch a while back). I'm hoping a 5mm-6mm thick aluminum base for my case will do the trick.

[qusp]

sure that should work, but you really will need to make sure there is good transfer to the sinks from the bottom plate. A plate that thick may of course be good enough all by itself depending on the size, perhaps do some calcs to see, as tghis will save a decent amount of money and effort if you can get away with it. as I said anything .55-.60C/watt for 80 degree rise and better will do.

[Horio]

The bottom plate may be enough, but I'd rather be on the overkill side. =)

I'm planning to use a chunk of aluminum bar (1" x 1") with a bunch of thermal paste to couple the sinks to the base.

[merlin el mago]

I think do the heatsink like the older Musical Fidelity Class A amps...

[qusp]

hehe these builds are gonna look way cool, dacs that look like power amps

well done opc youve created a new genre, the power DAC

[Horio]

A DAC with a soft start circuit...I like the sounds of that.

[qusp]

dont laugh, I have a hypex softstart, partialy because its also an LED and momentary driver, but the softstart doesnt hurt