which ebay DAC do I want?

[nullstring]

I am looking to purchase one of those assembled DAC kits that you find on ebay.

I'm looking for the best value under $150.
I know there are threads, but they are massive and full of possibly outdated information.

So, basically, want to know-

1. which DAC is the best value in my budget?
2. Is the transformer worth purchasing? If not, where do I get a different one?
3. Is there any comprehensive documentation on the best modification that might be done?

 

[nullstring]

alright, so I have been doing some reading of the gigaworks big dac.. getting bits and peaces of information.

Seems R-Core transformers are suppose to be ok, but I can't seem to figure out if this applies to the one that comes with the kit.. or if one can be obtained for cheaper than $30..

Looks like it's suggested to use a transformer instead of the second op amp, but I can't find much information about how you do this or anything.

Is there a keyword to use when searching for information like this?

 

[abraxalito]

[*]which DAC is the best value in my budget?

Really its a matter of taste for which features you want. I myself would lean towards a current output chip as the basis for the design - so either TI or AD rather than WM or CS.

Is the transformer worth purchasing? If not, where do I get a different one?

Depends - if its a toroidal I'd avoid it for the high capacitance to mains, which brings RFI problems. Otherwise, yes its worth getting with the DAC.

Is there any comprehensive documentation on the best modification that might be done?

Depends on which design you choose. If you choose one like in my blog, then yes, I'm writing some comprehensive documentation as I've modded it for excellent sound compared to how it started out.

 

[gripracer]

In the Delta-Sigma/Oversampling category:
The CS4397/8 DAC is one of the best when it is modded according to "Lampucera", search google for the page. Also, it doesn't even need an output stage. You can run directly out of the DAC and it sounds awesome. However, when you combine the differential outputs with high-quality output transformers (Lundahl, Sowter, UTC A-20), it's the best performance-for-money DAC there is.

In the R2R/Non-Oversampling Category:
The AD1865N-K board is the best, even completely stock. There is a reason that Audio Note uses that chip in all of their DACs. The on-board I/V stage is already pretty damn good, but a 6N2P-based tube I/V will sound even better.

 

[Bill Fuss]

IMHO, the newer stuff, R2R or Delta Sigma, is so damned good if modded correctly, that you will find the ultimate shortcomings in the signal that is fed to it larger than the differences between the units. When you can hear the differences in digital SPDIF cables and USB units that is a telltale sign.

I have PCM63 based, 1704 based, and CS4398 based. They are all great but the 4398 with OP trafos fed from I2S is the standout.

 

[nullstring]

Oh man, you guys couldn't make it easy on me could ya?

Bill, what is your opinion on these DACs in the case that I will never be feeding the DAC I2S? I will likely be using USB throughout most of it's life.. and perhaps getting a USB to SPDIF gadget, but I don't have any sources that would output I2S.
(Seems I would need a UDB to SPDIF gadget right away in the case of the AD1865 based DAC)

I am leaning toward the CS4398 DAC right now.. mostly out of lazyness and the promise of best potential and modest price.
My plan is to simply replace the opamp at first and then worry about output transformers when it comes time to build my cavalli EHHA. Right now I am using a puny SSMH headphone amp, and I am thinking that, that will be the definite down fall of the chain currently.

However, I am reading promises of better dynamics from the R2R category... tough call..

Decisions decisions...

On another note, if I were to buy a third party power transformer what are my options?
Or is the gigawork transformer really up to par?



Any further input will be greatly appreciated.

thanks,
nullstring

 

[Ipanema]

This AD1865 board looks fabulous iff it delivered as promise. Seller does not have any past sales record. Any comment?

AD1865 x2 differential mode DAC board with reclock USB - eBay (item 200495118826 end time Jul-19-10 13:16:04 PDT)

 

[SoNic_real_one]

I would be weary to buy from an user with zero feedback. Sure, looks nice in the picture and you can get the buyer protection, but still...
Then, the reclock is done in the Altera Max II chip - that implies some kind of software algorithm. How much can you trust that?

 

[tritosine]

I ve contacted the seller, if you want oversampling stay tuned for 32x version. Pretty sure its legit.

Duno about reclocking stuff, seems like http://focus.ti.com/docs/prod/folders/print/pll1705.html its used in this manner.

 

[SoNic_real_one]

That's just a programmable PLL clock. The Altera chip supposedly changes the sample rate of the incoming signals.

 

[tritosine]

That's just a programmable PLL clock. The Altera chip supposedly changes the sample rate of the incoming signals.

-well one has to turn that off then ,seriously IDK whats that supposed to do.

-not sure 32x os is good idea either cause glitch contributon might go straight thru the roof, I dont think this chip is either sign magnitude or has that ad1862 offset way to prevent glitch.