Adventures with a Soldering Iron Part 2 (DAC Build)

BrumjamBrumjam
edited June 2013 in DIY
Having enjoyed building (well, assembling) my nCore amps I've decided to have a crack at building a DAC.  This build will be a bit more complicated because the DAC will arrive as a pile of bits that need soldering onto the respective boards.

So which DAC is it I hear you say?  Here is a link to the designer's website that explains all about it:


It's a NOS DAC based on the PCM1794 chip. My initial build will consist of one DAC board but it is possible to stack the boards.  In standard form the only input is USB, but it is possible buy an S/PDIF board for it as well.  Output transformers or fancy caps can also be added but for now I'll stick with the basic build, consisting of:

DAC board
USB input board
5v power supply for USB
12v power supply for DAC board

Total cost for these parts was £350.

I've heard a version of this DAC with four boards/upgraded caps which was very impressive.  Just need to find a suitable case for it now and I can start building.  Pics and more information to follow soon.

 
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Comments

  • AlanAlan
    That's ambitious, James! Well done mate - I hope the build goes well.

    Has the DIY bug bitten? - I mean, do you simply fancy making your own gear - or do you expect to make something that is better than the Perfectwave, the Octave, Weiss, etc?

    I take it the modded DIY DAC you heard must have been pretty special?
  • uglymusicuglymusic
    That does sound ambitious James!

    I'm starting to feel left out from all you Soldering Iron Jockeys :-)

    I'm going to have a look at that link later.
  • BrumjamBrumjam
    That's ambitious, James! Well done mate - I hope the build goes well.

    Has the DIY bug bitten? - I mean, do you simply fancy making your own gear - or do you expect to make something that is better than the Perfectwave, the Octave, Weiss, etc?

    I take it the modded DIY DAC you heard must have been pretty special?
    The DAC I heard had four DAC boards plus mundorf caps. It's about three times more expensive in this guise. Sound quality was very good - didn't have my DAC with me to compare, so Im hoping the DIY DAC runs it close for SQ, although the features count will be well down on my current DAC.

    Definitely looking forward to the build and hoping to learn a lot more about electrical circuits than I do now.

  • sovereignsovereign
    What DAC do you currently use?
  • BrumjamBrumjam
    PS Audio PerfectWave DAC Mk2.
  • AlanAlan
    I read the story behind the DAC in that link James, and I can see why you want to build it. I would fancy it myself, TBH.

    I hope it goes really well, looking forward to your photo-diary, mate!
  • uglymusicuglymusic
    It does look good, doesn't it?

    Waiting to hear (and see) how you get on James.
  • DocfosterDocfoster
    I love hifi DIY when others do it.
    Imagining what might happen to treasured kit if I tried it terrifies me.
    :-t
    I have soldered a few cables and plugs without disaster or death, but that's about it.
  • sovereignsovereign
    Just skimmed through the linked web site, VERY interesting indeed.  I would love to give this a go myself.  Do post your step by step progress, GOOD LUCK!
  • sovereignsovereign
    I couldn't find it on the web site, but is it possible to have a volume control/digital pre amp on this DAC?
  • uglymusicuglymusic
    Now, that might be a good thing.
  • BrumjamBrumjam
    No mention of digital pre capability in any of the information I've read so far. You could insert a Lightspeed for volume control - that's the most transparent attenuator I've heard to date.

    Interestingly the output can be balanced, so I could try going direct into my power amps and using software volume control.
  • sovereignsovereign
    I am extremely interested in doing this DIY myself, I could raise the funds by selling other DAC's.
    I wonder if the £340 spent on the components will outclass the modified MDAC I have, I suspect it will 
  • uglymusicuglymusic
    No mention of digital pre capability in any of the information I've read so far. You could insert a Lightspeed for volume control - that's the most transparent attenuator I've heard to date.

    Interestingly the output can be balanced, so I could try going direct into my power amps and using software volume control.
    Going from software into Power Amps is dangerous. I destroyed speakers doing that when the software crashed and let out a howl.
  • sovereignsovereign
    edited June 2013
    No mention of digital pre capability in any of the information I've read so far. You could insert a Lightspeed for volume control - that's the most transparent attenuator I've heard to date.

    Interestingly the output can be balanced, so I could try going direct into my power amps and using software volume control.
    Going from software into Power Amps is dangerous. I destroyed speakers doing that when the software crashed and let out a howl.
    I had a similar problem and blew one of my A80's

    RD said my dac went AC or was it the other way round.
  • uglymusicuglymusic
    Oh, that's a pain.
  • sovereignsovereign
    Yup, 
  • DocfosterDocfoster
    RD said my dac went AC or was it the other way round.

    Your DAC went RD...?
    Blimey, that sounds violent and destructive.
  • uglymusicuglymusic
    Kept making upsetting noises, I hear. No one could figure out what it was on about :-D
  • BrumjamBrumjam
    The nice man from Parceforce has attempted delivery of a parcel for me yesterday - tracking details show it was sent from Germany.....I wonder what this could be?  [-O<
  • AlanAlan
    Get yer iron warmed up James! Best put some asbestos gloves on too...
  • BrumjamBrumjam
    I need to buy a new iron before I start  :-B.  The one I have is a cheapy from Maplins and it warms up my hand more than the metal  #:-S
  • AlanAlan
    I have the same iron...  ~:>
  • spacejayspacejay
    just bought the same dac although i suspect doede is on holiday.  can you tell me the size of the main board please?
  • BrumjamBrumjam
    edited June 2013
    Will do. Off to pick it up this afternoon.  

    Main motherboard is 14.5 x 12cm.
  • BrumjamBrumjam
    Here's what got delivered:

    image

    Top two boards are for the power supplies.  One 5v for the USB board and a 12v for the main board. The bottom board is the main board with the DAC board in position: 

    image

    Shot below shows how much case space will be required to accommodate the supplies, main board and USB board.  The power supplies can be stacked using spacers but I would prefer to have a wide slim case.

    image

    Plenty of soldering to do......

    image

    Close up of the DAC board.  Everything is very clearly labelled so this doesn't look like it will be a complicated build. The boards look to be very high quality:

    image

    One of the transformers with heat sinks:

    image

    Very much looking forward to getting going with this build.  I was concerned it might be beyond my basic DIY skills but having received the kit and looked through it I think I should be ok.
  • DocfosterDocfoster
    Merry bloomin' Christmas!
    :-)
  • uglymusicuglymusic
    Looks really good.

    I'm looking forward to seeing how easy it will be to build.
  • DocfosterDocfoster
    I'm assuming red PCBs sound better?
  • figlet108figlet108
    edited June 2013
    Hey James, I'm very drawn to following you down this rabbit hole with my soldering iron and seeing what lies at the end of the tunnel...
    My soldering isn't that great and I worry about making a mess of it, so I'll wait for you to do it first :)

    BTW, did you go for any of his  upgrade options?
    And do you plan to eventually go for the 4 DAC board option?
  • AlanAlan
    Well, my soldering is rubbish, but I reckon that doesn't look too scary. Srsly.

    Actually, this flush of confidence and bravado is usually an early warning sign of problems to come, IME... still, I never learn!

    Watching this with interest James!
  • BrumjamBrumjam
    Hey James, I'm very drawn to following you down this rabbit hole with my soldering iron and seeing what lies at the end of the tunnel...
    My soldering isn't that great and I worry about making a mess of it, so I'll wait for you to do it first :)

    BTW, did you go for any of his  upgrade options?
    And do you plan to eventually go for the 4 DAC board option?
    Hi Jason, no plans to go for 4 DAC boards or the Sowter transformers at this stage.  There are posts on DIY Audio indicating that there is more benefit to be had from using Tentlabs shunt regulators on a single DAC board, compared to buying four boards.  The regulators are about £35 each I think and four are required.  This is quite a bit cheaper than buying three more boards.....note that the 12v supply can support 8 boards which some people are now using. Costs soon mount up if you buy 8 boards, plus shunt regs for every one.

    The output transformers are meant to improve the sound but I don't want to end up with no play on my pre's volume control as a side effect.  They are also something line £650 per pair.

    I might look at upgrading some of the resistors over time.  Audio Note tantalum resistors are meant to offer an improvement over the supplied resistors, but I would need eight of them at £15 each :-O

    With regard to the soldering - if I can do it anyone can.  The only thing I've soldered before is the XLR and IEC connectors on my amps - in doing this I only melted two IEC inlet sockets ;)
  • sovereignsovereign
    I can solder copper plumbing pipes all day long, never tried little detailed stuff but I'm sure once I get the gist of it it will be easy.
  • sovereignsovereign
    I'll need to swap my torch for a soldering iron though
  • DocfosterDocfoster
    I'll need to swap my torch for a soldering iron though
    Presumably there's something in the DACs warranty...
    X_X

    Damn them and their small print.
  • figlet108figlet108
    James, that's really useful info on the upgrades and sounds like I should read up on diyaudio first and plan exactly what flavour of this I want to build before committing any cash.

    I'm still going to wait for you to do it first though. And then I'll orchestrate a dac-off at your place and make you think it was all your idea and I'll invite myself round and eat all your muffins...
  • spacejayspacejay
    aaargh.  dd is away on business at the moment apparently so i have no idea when i will get the kit.  i am off work next week so had some time to make a start on it.  

    have you got a case sorted for it yet brumjam?  do those shunt regulators replace surface mount regs?  don't fancy desoldering/ resoldering surface mount items...... 
  • BrumjamBrumjam
    No case sorted yet. Will build it on a piece of board first. The shunt regs replace surface mount items (four of them) so It's better to have them before starting the build to avoid desoldering. I've not ordered mine yet as waiting on feedback as to whether they are a worthwhile improvement.
    aaargh.  dd is away on business at the moment apparently so i have no idea when i will get the kit.  i am off work next week so had some time to make a start on it.  

    have you got a case sorted for it yet brumjam?  do those shunt regulators replace surface mount regs?  don't fancy desoldering/ resoldering surface mount items...... 
  • PACPAC
    edited June 2013
    Great project James.  The only tip I can offer RE soldering is to steer well clear of lead free solder, especially if this is a first kit attempt. It's difficult to use properly and on a kit that involved, if soldering skills aren't well practised, you'll likely end up with a lot of "cold" solder joints.  Leaded solder is much more forgiving, flows better, is less prone to cold jointing and easier to use (lower melting point).

    Also, RE AN Tantilium resistors...lets just say that my strong belief is that sticking with the resistors you have and weeding out any that are over 0.5% out of spec would be a wiser choice.  The biggest difference using the AN ones will have I suspect will tend to be in your wallet and nothing else.  Avoid this penchant for foo resistors as its the rating, type of resistor and tolerance that matter, not what designer label they use. Do you remember the Deuland foo resistor debacle a short while back?  Someone paid silly money for them, and broke one accidentally.  What do you think he found inside the ceramic casing?  It was a pencil lead LoL (seriously).

    I'll watch this with interest as it's a kit I was considering myself.  Have your sorted wiring?  I'd be tempted to use (properly rated) solid core OFC hook-up wiring and use shielded wiring for the signal incomers and outgoing wiring.
  • BrumjamBrumjam
    Hi Paul. Thanks for that. The solder I bought is 60:40 tin/lead, so hopefully this will be ok. I tried before with lead free solder and I agree it's a nightmare to work with.

    The wiring I've ordered from Maplin. Will dig out the specs later - this was the area I wasn't sure about so took an educated guess.
  • PACPAC
    Solder'll be fine.  Avoid using silver plated copper or silver cable as that needs silver solder or one of the many quad eutectic solders using silver/lead/copper/tin (best ones but pricey).  RS components is another good source for wiring etc.
  • BrumjamBrumjam
    edited July 2013
    Both power supplies and DAC board assembled over weekend.  Just waiting on delivery of wire to run from output points on main board to the RCA outputs.  Both power supplies turn on fine but I've yet to measure the outputs with a multimeter.  That'll be a job for next weekend before doing the last bit of soldering.  

    The MDF board shown in the photo is the same footprint as my PS Audio DAC.  I think the final case might end up being taller than my existing DAC due to the height of the heatsinks on the power supply boards. 

    Top right-hand circuit board is the USB input.  This can be powered by the USB input cable or via the 5v power supply board (which seems a no brainer).


    image


  • AlanAlan
    Great job, mate! That looks Luke a really fun little project, & I look forward to your comparison with your existing DAC.
  • sovereignsovereign
    GREAT!

  • sovereignsovereign
    Where do you live mate?
  • uglymusicuglymusic
    That was quick!
  • PACPAC
    Nice job James. If you wanted a formed Ally case for the project, I may be able to provide a link if you can confirm dimensions.  All you'd need to do is form the cut outs required.
  • BrumjamBrumjam
    Thanks Paul. That would be great. I'll PM you the dimensions when I get home.
  • BrumjamBrumjam
    That was quick!
    The benefits of having a kid-free house for two days
    :D
  • BrumjamBrumjam
    Where do you live mate?
    I'm in Solihull.
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