[Sodacose]

I'd love to build a DAC. No design experience though.

 

[Avro_Arrow]

Don't worry, I am willing to do the circuit design and boards.
Boards would be put up on OSH Park for public use (thus no group buy needed).
 
Lets see how much interest there is...

 

[Rroff]

  Sounds good.
I'm up for a solid state amp and a pcm1794a based DAC.
 
These would be built with easy to obtain components that
anyone can buy, no NDA or bulk buy required.
 
The amp would be something like the PPA2 (op amp with diamond buffer)
but with either two or four channels.
Also, the power supply would use the Kubota topology.
 
The DAC would use the PCM1794a but I'm up for suggestions
whether to do SP/DIF or USB and what controller.
 
Lets get this DIY section started again!

 
DIY DACs are a PAIN - I've been playing around with the PCM2902C with very mixed results* - soldering SSOP28 by hand is fun and games as well. Been looking at options for using the PCM179x DACs via USB but quite a lot of limitations on useful USB/I2S bridge chips available to non-commercial entities (could always use XMOS, etc. but half the fun is a ground up implementation).
 
 
 
* Think my main problem is the 12MHz crystal requires better quality connections than I've got setup on prototype board.

 

[FallenAngel]

New DAC would be great. We can always stick to spdif for simplicity but keep i2s option open.

 

[Rroff]

Little impulse one day build - works but lack of space for volume control and using 100K resistor divider for source attenuation bit me in the behind as its picking up a fair bit of interference from the input lead :| scoped the power section after I'd built that and its reasonable so don't think its power supply noise despite being USB fed.
 

 

[FallenAngel]

  Little impulse one day build - works but lack of space for volume control and using 100K resistor divider for source attenuation bit me in the behind as its picking up a fair bit of interference from the input lead :| scoped the power section after I'd built that and its reasonable so don't think its power supply noise despite being USB fed.
 

 
Love it! It reminds me of the minimalist designs of Sijosae!
http://www.headphoneamp.co.kr/ftp/sijosae/Gallery/
 
I loved that guy, learned a lot about super efficient layouts from his builds.

 

[Rroff]

Sadly can't even come close to Sijosae's ability to optimally use every last hole on a board heh - certainly an inspiration and a lot of the reason I built it was for the challenge of getting everything to fit.
 
Using the new revision of FCA series acrylic film capacitors for DC filter - seem quite good though I suspect the claims in the datasheet are a bit optimistic but I lack the experience or equipment to measure that.

 

[FallenAngel]

Sadly can't even come close to Sijosae's ability to optimally use every last hole on a board heh - certainly an inspiration and a lot of the reason I built it was for the challenge of getting everything to fit.

Using the new revision of FCA series acrylic film capacitors for DC filter - seem quite good though I suspect the claims in the datasheet are a bit optimistic but I lack the experience or equipment to measure that.

Don't sell yourself short my friend, your build looks really awesome! Why else would it remind me of a guru like Sijosae?

Great job!

 

[FallenAngel]

Building a sexy wire and realized that the braiding is off after the first six inches GRR! Most annoying!

 

[Rroff]

What is the cable for?

 

[FallenAngel]

  What is the cable for?

 
I actually just really love braiding string and wire, making different patterns and color combinations. This one was a gift for someone that bought an amp from me but I can't gift a cable that isn't perfect. It has to be perfect!
 
I think the first time I started braiding wires was around 8 years old for fun, using little wires to build square braids around pens. It was a lot of fun, so I just continued since then.
 
I'm probably going to complete the cable and have to cut off the ends to make it perfect.

 

[Fred_fred2004]

I have loads of CMOY pcbs so if anyone wants some for the price of postage??  just as a cheap way to give it a try
 
I should have a lot more boards that I need to quit as well I just need the time to sort them
 
cheers
FRED

 

[Rroff]

New DAC would be great. We can always stick to spdif for simplicity but keep i2s option open.

 
CP2114 starting to show in stock in places would have been ideal for i2s but its a QFN 32 package so way beyond feasible for most DIYers to hand solder shame they don't do it in a SOIC package.

 

[HiGHFLYiN9]

I've been depressed about this trend as well. Some of my favorite board designers/providers are getting out of the space, including Geek at Classic Valve and Shannon at DIYTube.com. As you've mentioned, Millett is doing most of his work with TTVJ, which makes sense, I'm sure he's much better reimbursed from that activity than providing boards and answering support questions for free. Hagerman Audio has also gone to turn-key products. I think what it really boils down to is offering DIY boards isn't terribly profitable, it's more of a community service. You can't really blame anyone for turning their priorities to something more monetarily rewarding, they may have family expenses or other financial obligations.
 
We still have some great kit and PCB options from Beezar, Dynakitparts, Tubes4HiFi/Bob Latino, Bottlehead, AMB, Kevin Gilmore, GlassJar Audio, and Decware (and more I'm sure I'm forgetting). I think Beezar and Bottlehead have discovered a good business model where some of the development cost is "baked in" to the kit cost. I don't think anyone would get rich from this type of thing, as DIYers tend to know the value of parts and would just migrate to other designs if the cost became prohibitive. 
 
I've moved my DIY activities to a blog where I have a bit more control of things, you may have stumbled on it.
 
This is a good spot for headphone amp DIY discussions:
http://www.diyaudio.com/forums/headphone-systems/

 

[Sodacose]

I reference your blog frequently when researching.  Thank you for the service you provide to the DIY community!