MicJames

Wow, thanks for the detailed explanation. That makes sense (in a general way, as I'm unfamiliar with details of digital audio processing), and also corresponds with what I found in a very limited experiment yesterday. I purchased an spdif iPurifier, and much prefer the sound I hear from it feeding a Lampizator L4/G4 than I do from the stand-alone ASCR jitter-reducer that I already owned feeding the same DAC. The experiment I ran was placing the two jitter reducers in a daisy-chain to see if the ASCR up-sampling from 44.1khz to 96khz sounded better through the iPurifier into the DAC than simply redbook resolution through the iPurifier alone. What I think I've discovered so far (more listening tonight and over the weekend in store) is that putting the iPurifier in front of the ASCR sounded better than putting the iPurifier between the ASCR and the DAC. This seems to correspond with the theory you outlined above, i.e., sending a cleaned-up almost jitter-free signal into an ASCR should greatly reduce the jitter that would otherwise become re-encoded in the output data. I'm secretly hoping I prefer the two in some combination to just the iPurifier alone, so I don't feel I wasted 4 times the money on the stand-alone ASCR/jitter reducer. Of course, maybe the ultimate solution is one iPurifier in front of the ASCR and one also in front of at the DAC, so that I get to spend more money. Ha! BTW, I've always read that a benefit of upsampling before the DAC is to bypass a potentially more damaging digital filter inside the DAC. Could upsampling through the stand-alone ASCR/jitter-reducer in theory improve the sound, or is this just wishful thinking on my part? Thanks again for all the info, and for a great, affordable product.

I was mistaken--the post I was referring to is earlier in THIS thread, and states that DACs employing a SECOND ppl after the receiver chip will not benifit from the spdif ipurifier. I gather, then, that the 1st two DACs tested above do not employ that second PPL?

Fascinating results. Thank you for posting. In another thread (perhaps another forum, even) someone from ifi said that the spdif ipurifier would be redundant when used to feed a DAC that employs a PPL for jitter suppression. These results show otherwise, do they not? The author of that post also stated that the ipurifier would be benificial when used with a DAC that employs ASRC for jitter suppression. Could you elaborate on why that is? It does jibe with what I've read about jitter becoming "embedded" in the data with ASRC, but have never quite understood how that works. Thanks for all the info!

Hi, Al. Have you had a chance to do some comparisons, and, if so, what did you think?

I certainly did overlook the DSD via USB only part, thanks. I guess I'm still confused whether the R2R ladder is used to process DSD, and if so, why it can't be fed DoP. I had read other posters mention that Lampi had developed a DSD via R2R, so I thought maybe it was implemented in the Atlantic.

I am anxious for feedback on the Atlantic. I've been using a PCM only L4G4 & have been debating upgrading the system with a DSD board and perhaps the R2R discrete. It appears the R2R board in the Atlantic handles both PCM and DSD? If so, a trade-in may be the smarter move. I wonder if the Atlantic can handle DSD via sp/dif DoP, since it appears the one R2R board auto detects and processes both PCM and DSD.

Hi, Wisnon. When you say, "That DSD also stops at 256," are you referring to DSD via R2R ladder? If so, can DSD be processed through the same R2R discrete board that processes the PCM? In the past you've mentioned having some friends who were experimenting with it, so I'm wondering what you've been able to learn about it so far. Thanks.

Interesting. Any feedback from those 3 or so regarding SQ? I wonder if this would allow for DoP over spdif, as well.

Hi, Wisnon, time to try to pick your brain again. What is DSD via R2R on Lampi? The site doesn't mention the discrete R2R board processing DSD as well as PCM. Are you saying one R2R board would process both, or that a separate R2R board is being designed to convert DSD? Finally, have you heard how it compares to the current DSD board? Thanks.

I hear ya regarding the good and the bad of constant improvements. Ever since I picked up a second-hand L4G4 of early 2014 vintage, I've been gathering info while considering various upgrades. Reading about the considerable sonic benefits of the DSD module had me convinced to have that installed at the very least. However, as ironic as it is for me to be reading and writing on this board, I am still a disc-spinner who has yet to really dive into the computer audio side, so once I heard about the R2R pcm implementation I decided to wait until some comparisons between the DSD and the R2R pcm become available, in hopes I wouldn't have to fuss ($$) with a computer server as well to get the best possible sound out of the Lampi. Now I suppose I'll hit the brakes a little longer to see how folks find the R2R and the new delta-sigma chip. Like you, genjamon, once I take the time, effort, and $$ to ship it back for upgrades, I'll want to take advantage of other recommended upgrades to the board or whatever that will improve the performance. Do you mind sharing what internal upgrades you opted for? Also, do you happen to know what the new delta-sigma upgrade runs, price-wise, relative to the R2R board? Looking forward to your take on the R2R pcm and the other upgrades. Hope it sounds great for you!

I would love to hear your take on it when you receive it and have the opportunity. I'm particularly interested in how the R2R pcm sounds to you relative to the DSD, as well as compared to the old delta-sigma chip. When researching the discrete R2R board, I saw that Lampizator now feels their newest 2016 Delta-Sigma implementation is on par and indistinguishable from the R2R. Here's the quote from the R2R page of Lampi site, and the link to, as well. "Our company is famous for relentless R&D efforts and since we have two different people responsible for DAC digital works - one for R2R and one for Delta Sigma - we witnessed a furious competition to create the superior DAC engine. The R2R sets the bar so high that it seemed a mission impossible in 2015 for the delta sigma DAC to even approach the R2R. However in early 2016 we developed a new improved delta sigma DAC that redefined whats possible in this technology. In our internal (very accurate and long) testing we concluded, that both techniques became equally good. This allows us to offer BOTH technologies to our customers without any preference from our side which is used. The customer will not be able to distinguish himself which is which. It is only the matter of subjective, non audible preference of the end user." R2R DISCRETE If that's the case, what factors into choosing one over the other? Assuming for the point of argument they do sound indistinguishable from each other, are their other inherent advantages one method has over the other? For some reason I had assumed that R2R pcm conversion was limited to 16/44.1, but that doesn't appear to be the case.

How does that work if the clocking is coming from the USB module on the DAC? And I legitimately mean that as a question, not a disagreement. I'd like to understand it if I can. Thanks

It wouldn't eliminate the advantage, but I think it would be pointless since the clock is provided on the USB side rather than the data transport side. The USB input at the DAC is the "master" in the master/slave clock relationship in the asynchronous set up, I believe. That is my understanding from reading, but I've no first-hand experience with it.

Thanks, Bonzo. Did you find the L7 far superior for PCM as well as DSD? Most of the rave reviews I've read for L7 seem to cover the DSD side but barely mention PCM.

Did you ever get the chance to compare L4 & B7? I own an L4 and will either be sending it in to have the DSD module installed, or saving the upgrade $$ to apply to moving up to a B7, if the sonic difference between the two warrants that move. How did you find they compare? For that matter, since you had all 3 levels at one time, how did the B6 perform in comparison, as well? Thanks!