Thanks Ted! I had heard of MLP, but either didn’t know or forgot that it was a part of DVD-A. Now if I can just keep remembering this the next time it comes up …
Good points, I would never again buy a chip based DAC that maybe obsolete in a cpl of years. To me, the options are PS Audio and Chord that provide FPGA solutions, upgradable and pay attention to details most don’t.
PS. So you think Chord is only using FPGA for upsampling?
I don’t think the upgradability is a requirement… it is certainly nice, that is for sure. But not a requirement.
My very old Accuphase CD player/processor still sounds great today. Great stuff remains great stuff especially given the maturity of this technology and industry. There is always room for innovation and improvement, but really, we are the point that … well how much whiter can your whites get? I always want more but really…
Besides, what about “taste” and system synergies? Lot’s to consider beyond making one aspect a requirement at the exclusion of all others.
Peace
Bruce in Philly
I don’t know the details of all of the Chord DACs, but Rob Watts’ talk about his work only talked about upsampling in the FPGA and only showed upsampling in the block diagram, still I could have missed something, perhaps he was talking only about upsampling and didn’t want to cloud the talk/slides with other details. The output is clearly a nice discrete implementation, tho if someone looked closely at the DS they might categorize it as something complicated too, tho it’s only a low pass filter. I don’t really know which features of each non FPGA chip in the Hugo, etc. are used for what, and the DS also uses a separate chip to receive USB and another to talk to Ethernet. Still the Chord might support upgrades of the code in the ARM processor, tho it doesn’t support upgrading the USB receiver code.
Chord has a YouTube video up where a narrator talks in semi-technical marketing speak about how their FPGA system is so diffferent to a chip based design. They focus on the WTA filtering, upsampling to 102MHz, noise shaping, and output from the FPGA via a set of “flip flops” that are closely coupled to the clock. So it sounds more similar than different in terms of architecture – though they’re using an active output stage rather than a passive one.
There was some other stuff about ten streams of staggered parallel outputs with something to do with getting better time precision that I didn’t know what to make of.
OK, opening this up again… my follow-up is the DIFFERENCE between these two, if used as pre-amp as well?
I see the output levels on the two are quite different due to output stage, which works best for a solid state amp (Classe CA2100)? Is there a way to tell before trying? Like looking at spec of the amp and output levels of the DAC in mV?
Thanks
The output levels are essentially identical. There’s no practical difference between them as far as which to use on an amp, except possibly for very long interconnects or very high capacitance cables (say > 10nF)
Ok, thanks so as long as I am using good quality interconnects in short length, either should work just fine as pre-amp? I could use either Balanced or XLR, would it make a difference?
Reason I am asking is some other forum, a few mentioned they had issues using Jr, as pre-amp, but maybe an isolated case.
XLR (balanced) instead of RCA (single ended) would both eliminate a little common mode noise (not a problem in many systems) and it could get you a 6dB boost in gain (probably good in most systems.)
It’s hard to judge just from numbers whether you’ll get the dynamic range you’ll want without too much noise. If you have sensitive speakers or a high gain amp you may need to be running the volume at a low setting. There’s a 20dB analog attenuator in the DS Jr that will allow lowering the noise floor by 20 dB and letting you raise the volume setting by 40. That helps match the system levels in many systems. If that doesn’t get you to the right place some people use inline attenuators… The real answer is a preamp (which I recommend in any system, if you don’t need one now you will later.) But many systems (not all) work great without a preamp.
The DS Sr is has 6dB less noise (because it has 4 times as many output stages), that may matter in some systems without a preamp.
The sensitivity of 1V RMS for rated output means the DS will be able to drive your amp to it’s max. But then you need to take your speaker’s sensitivity and how big your room is, how loud you like to listen… into account. I really doubt that the DS Jr will be unable to get things loud enough, the real issue will be will it be so loud you’ll have to turn things down so far that you are getting near the noise floor of the DS. You should probably try it and if you have too much noise come back to the forums or call PS Audio support: we may be able to help you with “the standard tricks”, but you can be assured that at worst a preamp will work.
Thanks, my speakers are 88dB, Nominal impedance, 8ohm, min. 4.6ohm. Room is like 15x10 ft
Right now, using my receiver as pre-amp, I typically listen at -30 to -25dB level, barely ever get to -10dB from max!
Have another follow-up on this… I currently have a HT act as pre-amp, sending RCA out for 2-ch audio to my Amp, and it does the D/A as well as LFA to subwoofer, AND it’s the volume control.
Now, what happens when I add a DS or DS Jr to the mix? I have to keep the HT for 5-ch audio D/A and movies, so how do we connect the other? I could use Balanced audio from DAC to Amp, and program my remote to take over volume control when I switch to 2-ch audio… however, what happens for LFE output to the sub? Since I won’t be sending any sound to the HT, how could the subwoofer come into play? Could I use the RCA outs from either DS to the HT? Then use HT to send the sound below 80Hz to subwoofer?