A toast to PGGB, a heady brew of math and magic

[austinpop]

There aren't many products where I can say "I was present at the inception." But with PGGB, that is definitely the case. For several months, @ray-dude, @romaz, @Zaphod Beeblebroxand I had been comparing notes on how to optimize the SQ of our Chord DAVEs using various strategies with HQPlayer and other options. In the course of these, @Zaphod Beeblebrox came up with the seed of PGGB, built a prototype, and the rest, as they say, is history. The last few months, as PGGB went from prototype to alpha to beta, and imminently, release, have been a whirlwind. I am amazed at just how big an impact this process makes on SQ. 

 

The website describes the principles around which the tool is based, so I'll focus instead on the end result. What do PGGB remastered files sound like on my DAVE?

 

When I compare a native PCM track to a PGGB remastered track, the areas of improvement are:

1. Density. Instruments and voices have far more realistic body and dimension to them
2. Timbre. Instruments sound like real instruments. When a drum gets thwacked, you sense the volume of the instrument, the texture of the "skin" being struck, whether it's fingers or mallets being used, etc.
3. Soundstage. PGGB portrays a holographic, 3-dimensional sense of the performance space.
4. Coherence and detail. There is just a wealth of detail that rises out of the lowered noise floor, that you just didn't notice before. You hear new things in your recordings, new sounds, new bass lines.
5. Bass articulation. The presentation has a tighter, more articulate bass.

And what's amazing is that the biggest impact on SQ in many cases has been on 1FS (redbook) recordings that had been languishing for years in my library. Many of my 1FS albums are now sounding as good as, or even better than, some more recent hi-res purchases.

 

Finally, and most important of all: PGGB has led me to rediscover, and fall in love all over again, with my library. That's priceless.

[austinpop]

1 hour ago, rando said:

Since you are acting ambassador(s) for this commercial entity, correct?

 

Echoing @ray-dude's point: I have no commercial affiliation with this product, and paid the same $500 fee as all customers do/will.

 

I've actually known @Zaphod Beeblebrox  a long time as a fellow audiophile and DAVE owner, and while I knew he did "DSP stuff" in his day job, I did not realize he had such hidden talents! So yes, I do wish him well in this enterprise, but in truth, all I'm suggesting is people try this for themselves. The results will speak for themselves.

[austinpop]

  

1 hour ago, Exocer said:

Sounds interesting but I wonder if I can utilize this effectively with the Yggdrasil DAC. I have a rather small library of flac files which sound really good in their default redbook format. Would the idea be to upsample these files using PGGB to the highest input sample rate of the DAC? Or, would it not be so worthwhile with a DAC that accepts only up to 24/192?

 

Cheers,

-Rob

 

 

 

Hey Rob,

 

I'd strongly recommend folks check out the website at https://www.remastero.com/pggb.html, as there's a fair amount of detail there. Specifically, the DACs section will address your questions: https://www.remastero.com/pggb.html#dacs

 

This project started with the DAVE as the target, but we (collectively) are learning that this approach works on other DACs too. While this is not a definitive association, the improvement due to PGGB on a DAC seems to be higher:

• as the max sample rate increases. Chord DACs go up to 705.6/768 or 16FS. Users have reported great results with 32FS DACs like the Terminator+ and the May - although the latter is difficult to get functional at 32FS. I have personally only tried PGGB on 3 DACs, and the improvement I observed was:
  • DAVE (16FS): massive
  • iFi Pro iDSD (16FS): large
  • Ayre QX-5 Twenty (8FS): marginal.
• if the DAC does NOS when presented a signal at the max rate. For example, the Chord DACs will skip the internal WTA1 filter stage when presented 16FS.

The Yggy, being only a 4FS DAC, may not benefit as much - I don't know. But download the trial and give it a try to see what you think.

[austinpop]

1 hour ago, Jean Paul D said:

I don't have enough RAM to generate PGGB files, I have a SD DAC I feed SDM via HQP per @Miska 's recommendation and logic behind HQP and thus PCM is not at its best with my DAC, PCM 8 fs capable though,  but I'll be happy to test if a proponent is willing to send/process me a file

 

Pardon my ignorance... what is an "SD DAC?"

 

If you're finding it works best with DSD from HQPlayer, and that it tops out at 8FS, I'm not sure how much it would benefit from PGGB.

[austinpop]

Can you clarify specific brand and model?

[austinpop]

23 minutes ago, happybob said:

thinking I may just buy a separate PC (have a need for that anyway) 

 

This was my situation (had a need anyway) and so I bought a new desktop with enough capacity. My config is listed on ZB's website here: https://www.remastero.com/faq.html#Sample

 

30 minutes ago, happybob said:

And related, how long does a given 44K track take to convert on a very high performance machine (like a Taiko Extreme)?

 

Ironically, while the Extreme is a music server par excellence, it isn't exactly the ideal machine to run PGGB — mainly due to its memory capacity of 48GB. Most Extreme owners I know have chosen to do their PGGB processing offline on more suitable hardware.

 

9 minutes ago, Zaphod Beeblebrox said:

It depends on the length of the track on CDs but, if you have at least 32GB of RAM and a fast drive for virtual memory, you can expect 3x or higher rate. So a typical CD album may take  15 - 20 minutes to process.

 

Exactly. We find a good metric to track processing speed is to use the ratio of track time/processing time. On my machine (above), I easily get 3.2-3.8x for Redbook tracks. Even "heavy" loads like long DXD tracks come in at over 2x.

[austinpop]

1 hour ago, Johnseye said:

@ray-dude, @romaz and @austinpop here I thought you guys were just kicking back and enjoying your Extremes.  Great to hear you're continuing to explore new improvements.  Thanks for all your efforts, and of course thanks to Zaphod.  I'm looking forward to hearing how this impacts the music.  I'll be checking this out with the Hugo TT2 and Omegas as well as with the new Holo May in my main listening environment.  I know you guys are huge DAVE fans, but if you ever get the chance to listen to the May, I'd love to know what you think.  I'm very impressed so far and it's just breaking in.

 

Hi John,

 

Long time no see. Hopefully we'll get to meet in person at AXPONA some year.

 

Yes indeed, I am indeed content to be off the hardware hamster wheel, but my ownership of the Extreme has just underscored the importance of software. PGGB has been a major exploration, but equally important has been the collaboration with Emile and the Taiko team on their TAS player, and other software tweaks.

 

You're teeing up an exciting comparison for sure! Are you able to run the May at 32FS? I've been tracking the discussion on the thread, and getting the thing to operate at 20/32FS seems to be difficult. Hopefully you'll at least get it to work at 16/32FS and at 20/16FS. And as Ray already mentioned, be sure to process content for the TT2 at 32/16FS.

 

I will be curious to know for each DAC, the SQ difference before and after PGGB. Additionally, how they both compare to each other with the best configuration of PGGB.

 

1 hour ago, Johnseye said:

I had been enjoying real time upsampling with HQP's sinc-L filter and LNS15 shaper.

 

 

This is still my configuration for listening to streaming music through Qobuz.

[austinpop]

41 minutes ago, Dev said:

 

Unfortunately, I run only 8Gb for sound quality reasons. Yes, the DAC supports 768khz 32 bits

 

We're still establishing which DACs will benefit from PGGB. 16FS (768) is a good sign. A NOS mode is another. A practical way to tell if it's worth trying PGGB is to first see if real-time HQP PCM upsampling using sinc-L/LNS15 produces an SQ uplift. If it does, then by all means try PGGB and see what you think.

[austinpop]

1 hour ago, Johnseye said:

I expect to further be astounded and will share my experiences.

 

Looking forward to it.

 

Quote

I do have an open question however as the May is a 32 bit dac.  Jussi has recommended output at 20 bit for the Holo Spring.  I'm curious as to why we wouldn't be creating 32 bit upsampled files, as you mention 20/32FS.  Was that based on feedback in the thread alone?

 

I'll let the DSP experts talk to this, but my understanding is that R2R DACs have a region of linearity up to a certain level of precision, and this can be determined by looking at the published noise plots. I believe Jussi established that for the May, 20 bits was optimum — at least that's my recollection. If it's a different number like 22, please use that instead.

 

By setting Output Bit Depth in PGGB (or DAC Bits in HQP), you allow its noise shaper to set the output precision to be optimum for the DAC. When you select 20 bit output depth, PGGB will generate 20-bit samples, although they will be written out as 24-bit numbers in the WAV container (file). Then, when your music player sends these samples to the DAC, it may further pad these 24-bit samples to 32-bit, but this varies by DAC, and its USB controller (XMOS, Amanero, etc). So things can get complicated, but the ultimate idea of the output bit depth is that after the data has been transported and received at the DAC, the data is at exactly the right precision to match the linear range of the DAC.

 

@Zaphod Beeblebrox please correct any errors in my description!

 

EDIT: In contrast, the DAVE and other Chord DACs have been found to sound best with Output Bit Depth set to 32. We suspect this is related to the Amanero controller used in these DACs, which is why DAVE users are advised to generate 32/16FS files with PGGB. 

[austinpop]

35 minutes ago, taipan254 said:

For all those that have used PGGB in scale... How are you storing your large, remastered libraries? NAS? SSDs / HDs on your all-in-one server? NVME Storage on your all-in-one server? I would imagine the latter would be VERY expensive given file sizes, but the latter is also widely agreed upon here to be the best sounding storage option? Has something happened that has lowered the gap in quality between NVME and other storage methods that I'm not aware of? Or is the quality improvement from PGGB so large that the storage media and method doesn't really matter? 

 

That's a good question, and serves as a reminder of several constraining factors of using this approach. PGGB is great, but does come with some baggage:

1. As already mentioned, you do need at least 32GB RAM, with 64GB or higher preferred, to process your music. Of course, this can be, and ideally should be, an unrelated machine to your music server/player.
2. The resulting files are very large. With 32/16FS files, the storage needed is about 15-20GB per album
3. Network streaming is not amenable to this approach, so for me as a DAVE user, I still rely on HQP sinc-L/LNS15 fed either from Roon or TAS (Taiko Audio Server). The latter's sound quality runs circles around Roon, but in discovery mode for new music, I can't deny the elegance of the Roon user experience.
4. For local playback, a network store like NAS isn't really a good option, as even with a 1Gbps home network, the load time for a 4GB file can be significant at a max read/write rate of 100-110 MB/s.

Now to your question. My entire local library of ~1600 albums at native sample rate occupies about 1.5TB. After PGGB conversion, this would need ~32TB. While Emile assures me that upgrading the NVMe SSDs in my Extreme will not negatively impact SQ, I am reluctant to do it due to the cost. I currently have 8TB. So I am approaching this as a sort-of jukebox, in the following way:

• Of the 1600 albums in my local storage, I only truly care about say half of it, or 800-1000 albums, so only these get the PGGB treatment preemptively.
• To store this content, about 16-20TB, I will use my NAS which already has adequate capacity. This will be my upsampled repository or warehouse.
• At any given point in time, I'll keep a subset of this repository on my music server, say 300 albums, or 6TB. This will be my jukebox.
• From time to time, I will rotate albums in and out, moving them to/from NAS (warehouse) to the server (jukebox).

I've toyed with the idea of using external USB storage, but am concerned about the SQ. Further, because of the size of these files, it really helps to have disk read speeds of 100s or even 1000s of MB/s, which NVMe drives do provide. A well implemented USB 3.2 SSD, with appropriately clean power with external PSUs might prove adequate, but this remains TBD in my setup.

 

[austinpop]

2 hours ago, ted_b said:

Hols,

Nice to hear from you.  I am specifically asking about the May as dac.  When you say "I would choose 24 bits" do you mean in PGGB, HQPlayer, or both?  If just HQPlayer then are we led to believe you are choosing 32 or 64 in PGGB, and doing the LS15 noise shaping in HQP?  And default settings for PGGB (except noise shaping)?

 

Ted, 

 

Due to the time difference with Hong Kong, and since I'm aware of @hols experiments, I think the three scenarios he describes are as below. Obviously, this is provisional until he confirms.

 

24-bit

 

native file ---------> PGGB ----------> upsampled file -----> HQP ----------> DAC

                                    out = 32fs                                            filter = None

                                    output bits = 24                                  DAC bits = 24

                                    NS = Auto (On)                                   dither = None

 

32-bit

 

native file ---------> PGGB ----------> upsampled file -----> HQP ----------> DAC

                                    out = 32fs                                            filter = None

                                    output bits = 32                                  DAC bits = 24

                                    NS = Off                                              dither = LNS15

 

64-bit

 

native file ---------> PGGB ----------> upsampled file -----> HQP ----------> DAC

                                    out = 32fs                                            filter = None

                                    output bits = 64                                  DAC bits = 24

                                    NS = Off                                              dither = LNS15

[austinpop]

Turns out HQPlayer, in pass-through mode, is an excellent PCM music player, far better-sounding than Roon.

 

Too bad there isn’t a PCM Direct flag, but you can achieve the same with settings.

[austinpop]

@bbosler

 

There’s trial mode (AKA “the first hit is free”), so check it out!

[austinpop]

13 hours ago, AudioDoctor said:

@austinpop I am continually amazed at your willingness to go to extremes in the pursuit of absolute perfection in playback quality. While I am over here focusing on simplicity and robustness, you're pushing the envelope as far as possible with both hardware and software. Love it.

 

Thanks, what has made this so much fun is to have a like-minded group of tinkerers like @romaz @ray-dude and @Zaphod Beeblebrox. My experiments pale in comparison to some of the wacky things they're trying!

 

I will say that, ironic as it sounds, I really am on a quest towards simplicity! With the Extreme, I no longer have the spaghetti chain of little boxes and cables and power supplies. The network side is still the wild west — some day we will have a true breakthrough. But I have also found that with a music player like HQPlayer or Taiko's TAS, I can cue up an album or playlist, hit play, and just unplug the network. No more "my stack o' switches sounds better than yours!"

 

What about streaming, you say? Well, with PGGB, the gap between PGGB-remastered local content and real-time HQP-upsampled streaming content is now so vast, that I view streaming only as a window shopping experience. I browse, I discover, and what I like, I buy, and I PGGB.

 

All of us here know software is vitally important to SQ. OSes, music players, upsamplers — everything matters. But with my hardware stack as optimized as I could make it (or afford to), this last year has been a fascinating journey of discovery into how much software has an effect on SQ. This journey has been on two tracks. One is this one with PGGB, where I have learned so much about digital filters and noise shaping from @Zaphod Beeblebrox. The other is with Emile Bok of Taiko. Emile is a tinkerer par excellence, and he has enlisted some of us like-minded Extreme-owning tinkerers to "play" in his sandbox. This has given me a glimpse into impact of OS level tunings with the Extreme hardware, along with the nuances of music player design, the importance of USB drivers, and DAC USB-I2S controllers.

 

Since most of the above was embargoed or confidential, I have had little to say publicly over the last several months. While some if still is, I'm delighted I can at least now discuss PGGB in this forum. Although I can unequivocally state PGGB is a game changer on Chord DACs, and the DAVE in particular, I am genuinely curious to learn to what extent it makes an improvement in other DACs. 

 

That's why I encourage folks, especially those with 16FS and 32FS DACs to try it, and report back.

[austinpop]

12 minutes ago, ted_b said:

get the best version of your music, THEN PGGB it (or HQPlayer' it)

 

+1 to that.

 

5 hours ago, HeeBroG said:

In other words, would PGGB of 24/192 when available be superior to 16/44?

 

In general, my subjective experience is:

• PGGB improves on the original mastering, whether it is 16/44.1 or 24/352.8.
• PGGB's improvement seems greater, the lower the original resolution.
• With that said, there is no inversion: i.e. if the native DXD version sounds better than the native Redbook, then:
  • the PGGBed DXD will still sound better than the PGGBed Redbook version, although
  • the gap between the PGGBed Redbook and PGGBed DXD may be smaller.

One easy way to try it for yourself, is with samples from sites like 2L.no that make sample tracks available of the same recording, mastered to different sample rates. Try PGGBing the 16/44.1, 24/96, and DXD versions of a track and determine what you hear in terms of differences between the original, and between the PGGBed versions.

[austinpop]

4 minutes ago, ASRMichael said:

64gb ordered to take full advantage! @Zaphod Beeblebrox customer service is fantastic!  

 

Awesome. What is your DAC and digital chain, Michael?

[austinpop]

3 minutes ago, ASRMichael said:

DAC - TAD D1000, 384 dxd max.  you can see my profile pdf for the chain. 👍

 

Ah thank you, I should have checked your profile. Nice diagram!

 

Also glad to learn PGGB had a positive impact on your 8FS DAC.

[austinpop]

4 minutes ago, bbosler said:

OK, I tried it. I processed a variety of files with the default settings in PGGB to 16FS. I played them back using HQplayer with all processing settings set to none , volume at 0dB. 

 

Mac Mini >>> HQP >>> USB >>> Denafrips Hermes DDC >>> I2S >>> Denafrips Terminator Plus set to NOS

 

a little different but definitely not a "game changer." You may think the Mac Mini is the "problem" and maybe you are correct, but as is it sounds fantastic and no way I'll ever invest $25,000 in an Extreme computer to play music.

 

Maybe it is the difference in a Chord DAVE and the T+. If that's the case is it possible you are compensating for inherent deficiencies in the DAVE that the T+ doesn't have? Maybe I just prefer the R2R with no processing versus whatever additional processing the DAVE does. It does strike me as being a bit extreme to use PGGB to upsample to 16FS  and then the DAVE takes that file and upsamples it to 256FS. That said, if it works for you then I'm all for it ... for you. 

 

Not worth the trouble of converting and managing another library of files. Not worth buying all of the albums I really like that are included in my Tidal and Qobuz subscriptions. Not worth switching back and forth from Roon with HQP set to upsample  when I stream to HQP alone and changing settings each time I want to listen to the PGGB files. . Not worth $500... I would rather have 15-20 new records. 

 

Not worth means not worth it to me. I'm glad you guys are enjoying this so much but this isn't for me. 

 

Enjoy, and thanks to Zaphod for helping me get it set up.

 

Before you give up, do try PGGBing to 32FS, since the T+ does 32FS. Assuming you set output bit depth to something in the 20-24 range?

[austinpop]

It may be possible to reduce the PGGB output file sizes, depending on the preferred bit depth and sample rate.

 

One of the reasons PGGB outputs WAV is because the 32-bit, 16FS files needed for the DAVE cannot be stored in FLAC containers, since FLAC is limited to 8FS (352.8/384 kHz). WAV offers the ultimate flexibility, since it can accommodate higher sample rates like 16FS and 32FS, as well as integer and floating point samples. Once we discovered that WAV files can contain sufficient metadata tags to be useful, we just went with it.

 

Now that folks are finding that PGGB is beneficial with 4FS and 8FS DACs, it makes sense to perhaps offer a "Output compressed FLAC if possible" option, so that for these DACs, users can create much smaller remastered files (no bigger than commercial 4FS and 8FS (DXD) files), that could reduce the network and memory pressure of the kind @davide256mentions above. 

 

I mentioned this idea to ZB, and I could sense the wheels were turning.  

[austinpop]

34 minutes ago, davide256 said:

DDC = Denafrips IRIS which supports 768/24bits in over USB. Output is coax, max for IRIS is 192/24 PCM or DSD64 DOP

DAC's are Metrum Octave (192/24bits) or Chord Mojo (768/32bits). I prefer the Metrum for mid range integrity but the Mojo has better dynamics.

 

Are you feeding the Mojo through the DDC, or only the Metrum? I didn't think so, but just want to clarify: to get the benefit of PGGB on the Mojo, you'll want to process files to 32/16fs as ZB said, and pass them directly to the Mojo via USB.

[austinpop]

3 hours ago, davide256 said:

I'll try both. I eventually plan to upgrade to a Denafrips Pontus so that I can use I2S/768 from the IRIS. The Mojo really doesn't gain much from the IRIS

 

Just keep in mind that you're trying to offload the digital filtering in your DAC to PGGB. With the Mojo (and Chord DACs in general), this means your goal is to bypass the WTA1 stage in the DAC. To do so, you have to present the DAC with a 16FS signal, which you can only do through USB or DBNC (not sure Mojo supports this? H2, TT2, DAVE all do).

 

Inserting a DDC that can only output 4FS (176.4/192) in the path will defeat this. So for PGGB evaluation on the Mojo, you really do NOT want the Iris in the path!

[austinpop]

28 minutes ago, davide256 said:

Doesn't defeat it completely since a well mastered HDCD (44/20) recording improved.

Hi David,

 

Just try it both ways (with/without DDC in the path) and see what you think.

[austinpop]

5 hours ago, Jean Paul D said:

From your own FAQ : "What if a song is composed of many 30 second recordings that all got digitized and mixed together? Any tap length more than 30 seconds would be using bad information. "

 

Not to mention an artist (ie Bjork) recording her voice in her bedroom and then completing the track in 3 different studios, even a classical movement is more often than the other way round made of splices of different takes. Seems to me that without knowledge there's a risk of doing serious harm in many cases with modern digital productions. 

 

Of course, analog tapes digitized in one effort escape that risk.

 

A question : I would be thankful to know how you define short length in the following (reference to HQP filters would help me digging ) "For the above reason, for short lengths, minimum phase have a significant advantage over linear phase filters. " 

 

Hi Jean Paul,

 

In practice, I have not run into any album/track where this was an issue. I've PGGBed hundreds of albums now, mostly classical, followed by prog rock, jazz, and a smattering of others. I've yet to hear a case where the PGGBed track sounded weird, nor one where it sounded worse than the original. 

 

Naturally, YMMV, so I'd say just try it and judge for yourself with your favorite tracks.

[austinpop]

59 minutes ago, mrkoven said:

Is there a way 32fs pggb files can conveniently co-exist with HQPe streaming within one library? maybe via euphony stylus?

ideally itd be great if HQPe automatically applies filters when it detects qobuz/tidal, then automatically removes filters when a local file (pggb) is played, etc

 

Not sure this is possible, unless you make a feature request to HQPe. 

 

Simplest would be to play back PGGB files directly via Stylus, without HQPe in the path.

[austinpop]

9 hours ago, kelvinwsy said:

l a hHave set None on both 1x and Nx filters as well as zero dither on HQPlayer Control Panel

Gustard A22 set to SLow and Slow PCM settings. Sorry No NOS mode on this DAC.

 

We've received a glowing report from someone with the older brother X26 Pro. Apparently this DAC, while ESS9038Pro based, has a true (claimed) NOS mode, and accepts a 10MHz reference clock. Still only 16FS, but would be an intriguing one to try.

 

9 hours ago, kelvinwsy said:

Nice effect is that on a High Spec Overclocked PC, the fans just dont come on. That comes with an advantage that one can use a low powered machine to play back the 16fs files. For 32fs it will be still a high spec machine I guess.

 

I don't see the A22 supporting 32FS, unless I missed it? So 16FS would be the sweet spot, same as for the X26 Pro.

 

9 hours ago, kelvinwsy said:

The SQ is really nice. I can guess 32fs files would be up there against the DSD upsampled files using say HQPlayer. 

Still testing but was so excited I got up at 5AM this morning to reallt try the 16fs files on my system

Intial Findings:

1. Frequency response quite smooth across the audible range. 

2. I do not hear any audible HF or Ultrasonic nasties.  -

3, I find the presence in voices and instruments to be good. 

4. Even on HF dominated music, the music never gets edgy or hot to the hearing.

5. Sound stage is nice, wide and positioning of vocals and instruments is good.

 

Will be experimenting on more  tracks. Highly recommended for those with capable DAC's (16fs and even 32fs), dont want to invest in a super spec PC to upsample and wishes to go fanless without concern about overheating issues.

 

 

 

Sounds promising!