"Value" DAC Options

[cogitech]

Thanks to this thread, I decided to give this one a go:

CS4398 CM102 CS8416IC DAC KIT 192K 24bit SPI I2S Amplifier Board | eBay

Check out this thread:

http://www.diyaudio.com/forums/digital-line-level/211321-dac-cs4398-cs8416-cm102s.html

 

[matt_garman]

Indeed. I have noticed the fixation on NOS DACs and I too want to know what all the fuss is about. My plan is to buy this DAC NOS1 NON Over Sampling DAC TDA1543T I2S Input | eBay and go straight from my CM6631A to the DAC via i2s. I'll provide clean, regulated power to both and see how I like it.

Cogitech, it's more than your stated budget, but I think this tda1387 x8 is a good way to see what all the fuss is about. The only "mod" I've done so far is to drop in better op-amps, and I really like the sound. Every now and then I hear some things that could use some more refinement, though the overwhelming majority of the sound I find quite pleasing. I'm hoping those last few refinements will come with the mods that have already been discussed in that thread.

In that same thread, someone also recently posted a 4x tda1387 dac available on ebay. It's much simpler (USB powered, direct-out), but also much cheaper ($40 shipped, though that's USD, probably higher for CAD). I haven't heard it but given how much I'm enjoying the 8x, it might be a fun toy to play with.

 

[spzzzzkt]

Yup, it's R2R. I don't recall anyone talking about glitching in either of the big threads on it. .

The DAM1021 uses a sign-magnitude architecture which inherently minimises glitching around zero, which is why it isn't discussed.

There is a NOS filter which uses x1 filter co-efficents - which is basically a "bypass" filter. There are two x8 upsample stages but there is no filtering done at either stage with the NOS filters installed. It sounds pretty good with NOS filters but tbh I personally think the DAM1021 is giving better results with filters using deep stopband attenuation. YMMV

The op amps are optional. The DAM1021 lets you uses three output options a) direct unbuffered output from the R2R ladder, b) buffered SE c) buffered and electronically balanced.

 

[abraxalito]

That's the same technique as used in the PCM63 (termed 'co-linear' by Burr Brown) isn't it? In which cases glitches around zero are exchanged for extra glitches at the -6dB levels (positive and negative).

 

[spzzzzkt]

That's the same technique as used in the PCM63 (termed 'co-linear' by Burr Brown) isn't it? In which cases glitches around zero are exchanged for extra glitches at the -6dB levels (positive and negative).

You'd have to discuss the details with Søren because I'm not really sure of the precise ins and outs of the design.

From what Søren has posted the architecture is not the same as the PCM63. It's similar but there are distinct differences. PCM63 uses shared current sources for upper and lower ladders whereas the DAM does not. The DAM uses thermometer DACs for the two MSB's whereas the PCM63 didn't as far as I'm aware.

 

[cogitech]

Cogitech, it's more than your stated budget, but I think this tda1387 x8 is a good way to see what all the fuss is about. The only "mod" I've done so far is to drop in better op-amps, and I really like the sound. Every now and then I hear some things that could use some more refinement, though the overwhelming majority of the sound I find quite pleasing. I'm hoping those last few refinements will come with the mods that have already been discussed in that thread.

In that same thread, someone also recently posted a 4x tda1387 dac available on ebay. It's much simpler (USB powered, direct-out), but also much cheaper ($40 shipped, though that's USD, probably higher for CAD). I haven't heard it but given how much I'm enjoying the 8x, it might be a fun toy to play with.

Thanks Matt. I've had to abandon my plans for the other budget DACs that I ordered, because Canada Post delivered them to another (unknown) address, so when I find a vendor that will ship me electronics via UPS, DHL, etc. then I'll start reconsidering my options. I'll add the TDA1387 to that list.