[Akathisia]

Is it possible to build an Alien DAC based on the Glass Jar Audio kit that has RCA outputs instead of TRS? Also as a follow up question, what kind of upgrades can be done on the Alien? I really want the best USB-in to RCA-out DAC I can get under $100 and I think DIY is going to be the way to go... Please let me know if there are other options or any opinions you might have.

 

[FallenAngel]

RCA - of course, and it's actually called 3.5mm (or Mini), TRS is 1/4".

Best upgrade : change output caps to nice film caps, I have a pair of AuriCap for home use and a pair of Sonicap for transportable, very well worth it.

 

[Daveze]

Agreed on the film caps. I've got one of FallenAngel's AlienDAC's with films (not exactly sure what type) and one with Black Gates. The films have that little certain something extra.

 

[Akathisia]

Cool, I will definately do a cap upgrade then, and any other components that could scale the DAC upward.

So, how would you do the RCA outs? Since it has a 3.5mm output now, isn't the ground shared? Wouldn't this cause problems when outputting with RCA?

 

[fault151]

im just wondering if i should make one for my millet max. I already have three dacs, not sure if id gain from it? How good is the alien compared to other usb dacs? I don't have a usb dac. I mostly use optical of my mac.

 

[Clutz]

I should talk to dsavitsk again about getting him to work on his HPDAC again, or even doing a release of one of his other USB DACs. HIs TDA1541A USB DAC didn't cost that much more than an AlienDAC to build and it beats the pants off it. In fact, in my humble opinion, it's better than the Benchmark DAC1 - but that's just me.

 

[kpeezy]

Quote:

Originally Posted by Akathisia /img/forum/go_quote.gif Cool, I will definately do a cap upgrade then, and any other components that could scale the DAC upward. So, how would you do the RCA outs? Since it has a 3.5mm output now, isn't the ground shared? Wouldn't this cause problems when outputting with RCA?

**Clueless noob posting

***

Isn't the ground for the 3.5mm jack 2 ground wires though? I would guess you would just separate them and use one for each RCA jack. I only make cables though. Is it different for a DAC?

 

[Akathisia]

Quote:

Originally Posted by kpeezy /img/forum/go_quote.gif **Clueless noob posting *** Isn't the ground for the 3.5mm jack 2 ground wires though? I would guess you would just separate them and use one for each RCA jack. I only make cables though. Is it different for a DAC?

I'm not sure if the Alien DAC has 2 ground going to the jack... I guess I could go look up a schematic

 

[Pars]

Almost all commercial stereo gear shares the ground between channels, so no, you don't need separate grounds for the RCA jacks, as they are likely tied together in the equipment anyhow.

 

[kpeezy]

Again, I'm an idiot who's never built anything.

So there is one place to solder the ground cable? Would you run two cables from that spot to the different RCA jacks?

 

[Pars]

Depends... you could. It all depends upon the construction of the jacks (ground tab? soldered directly to jack body?) and how you want to mount them. You could run a single wire (typical), run a pair of wires, or run a wire to one jack and daisy-chain the ground from that jack to the other one. Probably other ways to do it as well. I'd pick the one that you think would be the cleanest. The Alien DAC board has a single designated ground point, but there are other ground holes as well on the board, and they are all the same ground.

I just redid a board for strangedaze39 which had RCAs... I simply rewired them as he originally had them, with a single lead to the two ground tabs (with 3/4" spacing between the jacks which I believe is a defacto standard). I soldered the wire and the two tabs together at the same time.

 

[Akathisia]

Quote:

Originally Posted by Pars /img/forum/go_quote.gif Depends... you could. It all depends upon the construction of the jacks (ground tab? soldered directly to jack body?) and how you want to mount them. You could run a single wire (typical), run a pair of wires, or run a wire to one jack and daisy-chain the ground from that jack to the other one. Probably other ways to do it as well. I'd pick the one that you think would be the cleanest. The Alien DAC board has a single designated ground point, but there are other ground holes as well on the board, and they are all the same ground. I just redid a board for strangedaze39 which had RCAs... I simply rewired them as he originally had them, with a single lead to the two ground tabs (with 3/4" spacing between the jacks which I believe is a defacto standard). I soldered the wire and the two tabs together at the same time.

Cool so both RCA grounds go to the same place. Would you want to twist the L and R signal cables with the ground in the between the jacks and their points on the PCB for EMI rejection correct? So the best solution would probably be an individual ground wire on each jack that meet on the PCB ground point, or am I way off?

 

[da_burl]

You could also put a short piece of stripped wire (buss wire) between the two gnd tabs on the RCA's and solder the single gnd wire from the Alien to that.