Interesting, I suppose "brighter" can be considered as improvement by some. I came across some feedback on this DAC saying that it sounds muddy, perhaps this upgrade would make it less "muddy" for those reviewers. Hmm, I'm probably going to move this upgrade to the bottom of my wish list based on this. It would be interesting to see if the CS8414 SPDIF receiver alone provides any improvement over stock CS 8412 without swapping the digital filter, however they seem to be spec'd to the same 200pS jitter so probably not. Apparently some D/AC-1000s came with a YM 3623 SPDIF receiver that had significantly worse jitter performance (5000 ps?), so my guess the CS8414 upgrade alone (the YM-14-24 board from the German folks) would probably yield some improvements. I have yet to open mine to see what receiver I have.
I have 2 DAC, need help choosing 1
- Thread starter cortico
- Start date
xero-D-hero
Super Member
Probably could've taken care of the "brightness" situation with some basic opamp rolling. 
That's why I kinda have an "all-or-nothing" sorta POV on modding these Parasound D/AC-1000/1500.
In other words if one if going to do the 24/96 mod,,,then there's no reason NOT to put some sockets in there so you can roll opamps as well...
I personally have my eyes on the discrete opamps myself (SparkoS -or- Burson,have'nt made up my mind just yet).
Then all that would be left would be upgrading the -J to the -K chips,and IMO even that is'nt absolutely necessary.
Point is this thread reinforces the idea that these were some pretty dang nice DACs right outta the box.
And as such they can easily satisfy many users w/o additional mods (I have'nt felt seriously compelled to mod either of mine yet).
Also,I would be mildly curious how long that upgrade was in use before the "brightness" was deemed a permanent factor.
If it was a relatively short amount of time could be that those pieces did'nt really have time to (sigh,,,I hate this phrase) "burn in".
Anyhow,I dont think I'd bother with a NOS mod myself,as I'm not a "grass is greener" kinda guy,LOL.
But that definitely falls under the YMMV umbrella,,,to each their own...
Oh,BTW the D/AC-1000 I've had open so far has the Yamaha reciever chip (my first one)...
Dunno what the other one has yet ??? (as I have'nt cracked it open thus far)
JM2¢
Bret P.
That's why I kinda have an "all-or-nothing" sorta POV on modding these Parasound D/AC-1000/1500.
In other words if one if going to do the 24/96 mod,,,then there's no reason NOT to put some sockets in there so you can roll opamps as well...
I personally have my eyes on the discrete opamps myself (SparkoS -or- Burson,have'nt made up my mind just yet).
Then all that would be left would be upgrading the -J to the -K chips,and IMO even that is'nt absolutely necessary.
Point is this thread reinforces the idea that these were some pretty dang nice DACs right outta the box.
And as such they can easily satisfy many users w/o additional mods (I have'nt felt seriously compelled to mod either of mine yet).
Also,I would be mildly curious how long that upgrade was in use before the "brightness" was deemed a permanent factor.
If it was a relatively short amount of time could be that those pieces did'nt really have time to (sigh,,,I hate this phrase) "burn in".
Anyhow,I dont think I'd bother with a NOS mod myself,as I'm not a "grass is greener" kinda guy,LOL.
But that definitely falls under the YMMV umbrella,,,to each their own...
Oh,BTW the D/AC-1000 I've had open so far has the Yamaha reciever chip (my first one)...
Dunno what the other one has yet ??? (as I have'nt cracked it open thus far)
JM2¢
Bret P.
I should have explained the motivation for NOS better. This is not to listen to redbook in NOS mode per se, but rather to bypass all the ancient crap that's there in between the SPDIF input and the DAC chip itself, namingly the jittery Yamaha SPDIF receiver and the jitter-suspect DF1700 digital filter that runs a simple cascade FIR filter designed with compromises so it can run on limited hardware. Then you can upsample in software using high quality software filters such as those in HQPlayer, JRiver or SoX in Foobar (JRiver can do SoX too) and feed clean jitter-free signal directly to PCM63s over I2S. Yes unless you're a NOS fanatic this means you probably need to forgo the use with CD players and other traditional SPDIF sources, e.g. the CCA, but I don't use them anyway.
If you still have the chips, see what is the roll-off the DF1704 set to. I've been doing some reading on this subject lately and some suggested that the "Slow Roll-Off" mode can sound harsh and fatiguing, if set to Slow you can try setting it to "Sharp Roll-Off", there are likely soldering pads you need to short or open on the little PCB the filter sits on. In general though I came across multiple opinions from unrelated sources that the DF1704 isn't a very good sounding digital filter, and worse than the SM5813/DF1700 which is the original filter in the DA/C-1000.
I do wonder if replacing the input SPDIF receiver by itself is a better mod if one doesn't need hi-res (I know I don't). The CS8414 would need to be set to 16-bit LSBJ output (LSB - justified, or also called MSB-first right-justified) to work with the original filter SM5813/DF1700. Looking at the pictures you got a YM-14-24 upgrade (CS8414 replacing a YM3623) which is set to I2S output mode by default if the web-site is correct and I2S output format won't work with the stock filter.
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