My new, old DAC

J!m

Veteran and General Yakker
Joined
Dec 24, 2019
Messages
9,246
Location
Connecticut
Tagline
BOT
#1
So, about ten years ago I picked up an EBay DAC kit that was held in high regard over at diy audio.

I’m finally getting around to casing it up. I have tested it and it does function.

It uses an op amp output, so I picked up a few compatible replacements with better specifications to see if that is audible.

I also changed it from internal jumper position to external rotary switch for input selection. I’m adding a colored LED for each selected position for positive feedback of what is selected, even if you accidentally dropped your readers in the blender.

No copper this time (unless I do a copper knob) and the logo will be directly engraved into the black lace plate. (Unless it gets messed up, and then I’ll make it another silver face).

2FEA3E6C-0EA1-4E15-938A-C919B5BE367F.jpeg
 

J!m

Veteran and General Yakker
Joined
Dec 24, 2019
Messages
9,246
Location
Connecticut
Tagline
BOT
#4
Well, the ones in there are the cheapest available in China ten years ago… I have three or four possible replacements in hand. Some are “audio” and the others are just fast and quiet. Once (if) I hear the best sounding one I’ll identify it. Right now the numbers mean nothing to me, but I did make sure they are drop-in (same pin-out and voltage)
 

J!m

Veteran and General Yakker
Joined
Dec 24, 2019
Messages
9,246
Location
Connecticut
Tagline
BOT
#6
The actual converter chip is supposedly a decent one. But I found a drop-in replacement for a few bucks that takes lower end DA chips and runs several in parallel. I might go for that because that scheme usually lowers noise but also helps correct errors in the digital domain. Cheap to try…
 

J!m

Veteran and General Yakker
Joined
Dec 24, 2019
Messages
9,246
Location
Connecticut
Tagline
BOT
#10
Water jet finished the rear plate for the input connections. I’ll pick that up today.

Machine shop hasn’t got back to me on the front panel rework yet… I can work it enough to get it working but I’d rather assemble it once.
 

VSAT88

Veteran and General Yakker
Joined
Sep 7, 2017
Messages
1,798
Location
Phenix City Alabama
Tagline
Like my BlueTooth ?
#12
That's awesome. I built a Chinese tube preamp and put it in a cigar box. Lol. I have no idea what I was thinking. It actually looked kinda cool and didn't sound too bad.
 

J!m

Veteran and General Yakker
Joined
Dec 24, 2019
Messages
9,246
Location
Connecticut
Tagline
BOT
#14
I’ve got an R-core transformer to mount in the opposite corner and possibly a steel wall.

I put a line filter on the inlet, a better Schurter fuse holder and some gold bling Neutrik RCA connectors. The input plate ended up off the back wall a bit- for uh, ventilation. Yeah, ventilation.

I’ll get it all working and send out the front panel for machining when he’s ready for it.

I have already tested it so I know it works. I need to make sure the fancy selector with color coded LEDs works but it should.
 

VSAT88

Veteran and General Yakker
Joined
Sep 7, 2017
Messages
1,798
Location
Phenix City Alabama
Tagline
Like my BlueTooth ?
#16
Think someone will buy it? I couldn't give away the one I built.. HA! Naw for real it looks good to me. Those Neutrik connectors are great I think. Use them on all my interconnect builds.
 

J!m

Veteran and General Yakker
Joined
Dec 24, 2019
Messages
9,246
Location
Connecticut
Tagline
BOT
#17
Rean or whatever they call them. Good n cheap.

If I don’t sell it it was a fun project. And I’d sell it cheap because the DAC is at least ten years old now. I’ll see what I can do with it. And I can compare to the Aragon D2A, which is pretty decent, albeit old. Dual mono converters and discrete analogue stage.
 

VSAT88

Veteran and General Yakker
Joined
Sep 7, 2017
Messages
1,798
Location
Phenix City Alabama
Tagline
Like my BlueTooth ?
#18
Be willing to bet it sounds better than you might expect I may be crazy, well that point is not debatable but some of the older DAC's like in CD players I have had seem to sound better than some of the newer ones. Yeah, Rean, same stuff I think.
 

J!m

Veteran and General Yakker
Joined
Dec 24, 2019
Messages
9,246
Location
Connecticut
Tagline
BOT
#19
Well, I guess we’ll find out soon enough.

I can do a quick comparison of the converters in my $5 JVC DVD player to the DAC. Run them both to my boom box and see if it’s audible. I think the op amp experiments are better left for home with the good headphone amp and good headphones.
 
Top