EVS modified Gustard X20/Gustard X20 thread

[MarkK02474]

Oh my. With some warm up, break-in, and just a low-end AQ power cable, this thing is sounding even more full and 3d than my old EVS Oppo-83se. The filters are quite audibly different. I think I prefer the apodizing filter closely followed by L-slow for hearing the walls of the recording environment (Mobile Fidelity CD of Muddy Waters Folk Singer). Now its sounding very worth the money. I found in the Oppo manual that it won't pass SACD out the coax and fiber, only HDMI, or convert to PCM. Can't wait to do some mods!

 

[Ric Schultz]

I never listened to a Gustard without at least 150 hours on it. Everything needs burn in. However, I think I will give a quick listen tomorrow (maybe 35 hours constant playing into load) as I really want to see what this thing can do......and then immediately do the total level one mod and re-listen. However, even with burn in, the stock older version was still not acceptable to me. Now, after some of the mods....well, now we are talking. The full set of AC mods alone will transform it. Remember, if you are not using usb then please remove the usb board. Sounds noticeably better without the usb board. Have fun and let us know what you find. I will post about the level one mods in a couple of days. Looking forward to hearing the ESS9028 sound......and see how it is better? than the old 9018s. We shall see....er hear.

I will also be listening to the differences between the $30 Crystek clock, the $65 Abracon oven clock and also in a few weeks the $400 Pulsar clock from Italy. Currently, I use the Crystek in my clock mod.

By the way, the new Pro DAC is slicker looking with shinier anodizing, better knobs and cool covers on the transformers. The display is new and you get more digital filter settings than the old one and the very coolest thing is that the phase control actually works like a normal thang. You can just toggle back and forth while playing. The old version required you to turn off the machine and turn it back on every time you wanted to change absolute phase! Also, there is a usb stick with the driver, manual and test tones. Before there was just a small CD with the usb driver.....So, the machine is more slick looking and works mucho better. And hopefully, sounds better too! Amazing what less than $900 delivered can get you these days. Good job Gustard!

 

[Ric Schultz]

Oh my! This new ESS 9028 DAC chip is out of this world. I am hearing things on this CD I have never heard. So, clear, clean and full of harmonic information.

I listened to the completely stock Pro after about 65 hours of straight run in....into a load. It was good....nothing great but listenable. So, I just did the full AC mod (see website for details) and also removed the usb board since I am using coax in. OK....the cymbal is now outside the speaker a foot....the imaging is mucho better, it sounds more real......just really nice. Started to hear things that were new!....more info....cymbals more airier, more hall sounds....more subtle things.

Today I added some damping material to two caps and added WA Quantum chips to 4 caps to good effect and then tried WA Quantums on the DAC chips......that was not good so removed those. So, I decided to change the digital cable between the boards to my custom tweako cable and OMG it took it to another level of pure information retrieval. I sat there listening to this CD as if I have never heard it before.....and then suddenly I was crying.....really. This has never happened to me before. There is so much subtle information that you feel you are inside the musicians heart. The sound is still not as palpable and transparent and pure as level 2.5 mod on the old DAC but I am simply hearing more information than that level of mod. And I have not even finished level one mod! I still have more WA Quantum chips to add, much more damping and also changing the rectifier diodes on the DAC board. Then there is the clocks to try....and then level 2.....yikes....I may be crying a river before this is done.

What is clear is that the DAC chip is really a serious improvement. However, it is also really clear that most stock DACs will not showcase the potential of these new chips. You need some serious tweaking to reveal its magic. Of course, this has always been true but I have never had this kind of experience with so little modding and yet without the mods that I just did it was just good....not really good....just good. Now it is crying good! And there is much more to come!

As far as I know, these are the first serious comments by someone who has A/Bed the new ESS DAC chips against the old ones. The Pro Gustard is exactly the same as the old Gustard except the DAC chips. If you know of anyone else who has done this please let us know. I would like to read their comments. If someone A/Bs a stock old Gustard with a stock Gustard Pro they will not hear nearly the difference I am hearing. The power supply and clock cables have to be upgraded to hear this information.

Tomorrow I will finish level one mods and later this week try the Crystek and Abracon clocks. I will let you know how it goes, if I don't drown in my tears.....he he.

 

[Jeffy]

The ESS 9038 is the new dac chip.

 

[Ric Schultz]

Not correctomundo,
Please check the ESS site for details. The new "Pro" DACs are the 9028 which is a direct replacement for the old top of the line 9018 and the Pro 9038 which measures even better but requires a new circuit board. There is an even cheaper Pro 9026.

http://www.esstech.com/index.php/en/products/sabre-digital-analog-converters/audiophile-dacs/

Most of the DACs that have implemented the new Pro line are using the 9028 as it is easiest to implement and the 9038 DAC chips just started shipping in quantity. It will be interesting to see if the 9038 is really any better sonically.....will be hard to know exactly what the difference is as they will probably be implemented in new machines and new boards with new external power supplies, output stages, etc.......so knowing what the chip is doing by itself would be hard to know. This is what is cool about the Gustard Pro. We have the same exact machine/board except for the new DAC chips, therefore any sonic difference has to be the DAC chip.

Also, you have to take into consideration running them in mono. The Gustard is using two 9028s so has 8 DAC channels in parallel per channel. A single 9038 (like used in the new Ayre thang) has only 4 DACs in parallel. I don't understand why they did not use two 9038s in the Ayre. At $9000 I would want the best sound possible. It is common knowledge that mono-ing and paralleling DACs makes the sound better. So, do mono 9028s sound better than a single 9038?

 

[Ric Schultz]

Level one mod done and now it sounds in every way better than my old level 2.5 mod on the older Gustard. This thing is simply magical. My usual CD test disc now sounds like high res. Every mod I did made more difference with this DAC......well not really.....just that the new DAC chip has so much info that opening the windows and letting it all shine is so much more rewarding. The same mods are great to the old DAC but now you are releasing a magic man from his cage.....just sublime!

 

[jjk]

I will also be listening to the differences between the $30 Crystek clock, the $65 Abracon oven clock and also in a few weeks the $400 Pulsar clock from Italy. Currently, I use the Crystek in my clock mod.

Ric,
Since you are modding the clock or (taking it out of the chain?), can an external clock work as well? I am referring to the clock on a PinkFaun bridge card (OXCO). I would like to synch three dacs to create a multichannel system. The single card can support up to 4 machines. I2S is the method of transport.
PinkFaun dacs work like this and PS Audio also. Would really like to make it work with the Gustards.
Thanks Ric, Happy Holidays!

 

[bibo01]

Hi Ric,

When you input S/PDIF or AES/EBU, does signal get clocked to Master Clock of D/A chip?

 

[Ric Schultz]

The clock on the ESS DACs is a separate clock that the ESS DAC needs. It is the only DAC chip that I know of that needs a separate clock to run it. It is not the input main master clock. So, this has nothing to do with having a separate word clock input as some DACs do. So, no external clock input on the Gustard. As far as I know you cannot synch Gustards together....but I could be wrong.

I don't know anything about the internal clocking of any inputs in the Gustard (there is no schematic). Again, the clock I am changing is not related to the inputs.....it is a clock that the ESS DAC needs separate from any input clocking. However, the jitter of this clock is important.....hence the upgrade path pursuit.

 

[jjk]

Thanks Ric.

 

[MarkK02474]

New tweak: After finding my Molex tool kit, I removed the wires from the power connectors, cut off the tubing, twisted the power wires, and returned to the conectors.

New tweak is putting a clamp-on split ferrite bead around the power wires going to the input/clock board, closest to the board. These are the ferrites most commonly used on AC power cords. I used one here to reduce the amount of RF noise that could feed back from the board through the transformer, to the common AC cord, and into the other transformer to the DAC board.

Sonic result: A little quieter background and less glare. Only a first experiment. More possibilities.

I'm troubled by the LT 1763 regulators used by Gustard for AVcc on the DACs. This has a 20uV noise spec, which is worlds better than 78xx or 317 regulators, but 20x the 1uV noise, state of the art regulators including the new ES9311 have. AVcc is the most critical supply on most DACs and I'm curious if anyone has upgraded the ones on the Gustard. ESS didn't make a regulator chip for nothing - Good AVcc gets the most from their DACs.

 

[Ric Schultz]

Never liked ferrite clamps. I have removed them from Sony and Marantz products and have gotten better sound. Try the Mad Scientist Kegs....these are ferrites that do no harm.

You really must do all the AC mods to really hear what is possible. I remove all AC connections inside (2 power switches and 5 connectors), remove a cable and remove the AC filter. I also remove the entire circuit board mounted to the AC receptacle. I cut off the connectors on the transformer AC input wires and twist the wires together on both trannies and solder them directly to the AC inlet. No fuse, no nada. You turn it on and off by plugging and unplugging. Then you use two layers of cardboard underneath the trannies and get rid of all the tranny hardware. Then you twist the wires to the circuit boards. The result is way better sound. Then after that you need to change the rectum firing diodes on the DAC board and make a custom hardwired digital cable between the boards.....then you add WA Quantums and damping.......now you are crying.....with glee.

Just now ordering the $400 Pulsar clock. Now this could be something really quite special! After trying that I will get the output trannies and I also have another output stage that I want to try that could be less costly but still really great. I still hear the stock output stage.....(slightly veiled, compressed and transistory).......still, it sounds outrageous. But, a perfectionist wants it all!

Really hard to change regulators on the DACs. The trouble with specs is.....that is does not always correlate to anything sonically. There are many factors in a regulator that give better sound and a noise measurement is just one of them. You would have to A/B regulators using the same capacitors and solder and everything to know what they "sound" like. IE....all regulators with the same noise spec will sound different......this I have no doubt. Some regulators with a higher noise spec will sound way better than others with a lower noise spec....I have no doubt about this, as well....having listened to lots of regulators (monolithic, discrete, home made). Tweaking is never ending. But you need to concentrate on those places that make the most difference and do them first.....the regulators are way down my list.

 

[nsinggih]

Hi Ric,

firstly let me thank you for sharing your experiment to all of us here... I'm very new into this game, but, after reading through this thread, I've recently bought a Gustard X20Pro and do the simple modification that i can do myself: the cardboard under the tranny, twisting the cable, bypassing the fuse with a copper foil and some damping on the large caps like what you suggested on your website. Thanks a lot for that.

I've nothing to compare this against, except for an old DAC that i borrowed from a friend of mine (PCM based) and/or the DAC that comes with my amplifier (Micromega AS-400) and I can say that the Gustard sounds really good, and it does shows after the mod that the soundstage gets bigger, and the separation between instruments have also gets clearer... amazing thing this one.

One thing annoys me though, as I am using a RPI3 with Volumio as an Airplay receiver to carry my Tidal HiFi (from iPad) into the DAC (via USB), whenever there's a change in the bitrate (for example when RPI3 started/booted, as well as when I play around with HQPlayer and change from PCM to DSD), i am getting a pop noise that I need to remember to lower or switch off the amp before the bitrate changes... and, sometimes i forgot...

Is this also happening with your unit, and would you know of a way to handle this? Sorry if I ask for something so stupid, but this is my first attempt into the HiFi world and there's a lot that i still need to learn.

Thanks in advance...

 

[MarkK02474]

Ric, I'm generally with you on ferrites as they can deaden the sound, but I suggest you just give it a try. Its easy with no soldering and miniscule time investment. A quick A-B test. For decades Philips engineers have been using resistors and/or ferrites to isolate loads having capacitor bypasses and the main supply rails in order to keep the rails cleaner and reduce noise getting in all devices. Their mistake was doing the same to analog loads which need direct connections to not kill bass and dynamics. The CD63 is a prime example. So, the rule of thumb is to give analog circuits lots of current (ie bypassed ruses, soldered ac connections, reduced connections), but with digital circuits, noise control of MHz noise is more important than lots of DC current up to 20kHz.

I've got the cardboard and nylon hardware in, fuse wrapped in copper foil, 3M #434 dampening tape strips on the electrolytics, working on finishing the AC wiring you changes you suggest, and have Vishay HexFREDs on order for the DAC board. Clock upgrades sound worthwhile from reviews, and on my list. Maybe transformer outputs. I think there's always room for more, and quieter regulators could be it since ESS themselves are doing it.

 

[Ric Schultz]

Nylon hardware? The Pro has no epoxy in the center of the trannies (like the old Gustard) and therefore no small hole for screws.....the stock screws go through the steel plate on top. The steel cover plate HAS to be removed!!!!! You don't want no steel anywhere around a toroid tranny....nor anything conductive in the center. I have my transformers just sitting on the cardboard and not secured at all. For customers, I am going to glue the cardboard down and glue the tranny on top. For shipping, you add the steel plate and screw and for listening you remove both.

I tried small ferrite beads years ago on digital power lines and it messed up the sound. However, I will give a ferrite a listen on the digital power wires some day. On the Sony Happy One they have a ferrite bead on the digital cable between the main digital board and the DAC/output board. Sounded better with it gone. You have to listen to everything. Assume nothing. Because ESS does something does not make it worthwhile. I don't think they are tweaks (serious listeners). Most digital engineers are nerds (measurement freaks). Their new regulator might be the cats meow.....and it might also be a screaming alley cat! Again, assume nothing and listen to everything.

Happy New Year and happy new DACing! All DACs with old ESS DAC chips now obsolete.....he he. Happy birthday (yesterday) to me too.

I am only playing discs from my modded Oppo via coax. I always have the volume off when I change discs....so never noticed any pops as it changes from 16/44 to 24/96. You should always have the volume off when doing anything other than listening to be safe. You can mute the DAC with the remote or you can mute your preamp or whatever (I have a muting switch on the input of my amp that I always use).

 

[MarkK02474]

I'm not using the steel top plate on my transformers. I replaced the top plate with a 3" diameter, 1/8" thick rubber washer that's fairly stiff, and on top of that is a 1.5" diameter nylon fender washer for added stiffness, with the nylon nut on that. A second nylon nut adds more strength as the threads are fine. All this from my local hardware store. I think there might be a small SQ sacrifice with even just nylon and rubber holding down the transformers, but at least its all non-magnetic and fairly secure.

Sure, in the Sony example, a ferrite will sound worse. They are often used on cables for RFI suppression to meet FCC noise emissions, and its going to round off corners of important digital square wave signals. That's why I only considered a ferrite on a digital power line - no data corruption. Its like using only Hexfreds or Schottkeys in bridge rectifiers everywhere in your audio system. Noise from a standard diode goes back out the AC cord to pollute your mains, getting into all the other system components. The (best) alternative is unplugging components not in use like that FM tuner or cable TV box.

We can thank engineers for newer parts like low ESR capacitors and soft recovery diodes. They were developed to tame RFI from switching power supplies to meet FCC regulations and reduce interference with sensitive circuits, especially in medical equipment (ultrasound, MRI etc.). I use the new tools where appropriate to tame noise and enhance performance. Ultra low noise regulators intended for sensitive medical and communications use, not home audio, are another wonderful thing for us, still slowly working its way into more audio products, displacing ubiquitous old, slow and noisy 78/79xx and 317/337 regulators. When picking regulators, its not just noise figures but bandwidth and stability that count. The wrong capacitors on them can create oscillations. The new ESS regulator doesn't even need output capacitors, per their marketing sheet.

Nsinggih, I too am only using coax in from an Oppo transport and playing redbook CDs (wonderfully well). I plan to use higher res files with the USB input and later a USB to IIS receiver box. Word on the chat boards is that DSD512 requires an external USB receiver, so troubles with lower rates using the internal receiver make sense too. I've read that the ES9038 supports DSD512 and even DSD1024, where the ES9018/ES9028 only officially support DSD384.

Send a complaint to Gustard on the data/clock rate-change pop. Firmware in the Xmos receiver board or controlling the DAC needs to mute the chip or relay outputs during 45.158MHz and 49.152 MHz clock switching and data syncing. The 9028 is a brand new chip, and while pin compatible with the 9018, I'm sure there are many new features on it that manufacturers are still sorting out. A new feature of the 9028 is much faster data sync than the 9018. Maybe muting necessary for the old chip was removed for the new, thinking it unnecessary and happening faster than mute relay switching.

Also try the "auto" clock setting in the menu. Supposedly it allows for more adaptive clock use by the DAC and could help.

 

[nsinggih]

Thanks Ric and Mark, I've been controlling the volume manually now but hoping that there is something else that can be done. I will try to contact Gustard and see what can they do to help. I am located in Hong Kong. And bought my X20 directly from them (via Taobao) so hopefully they can do something here.

 

[MarkK02474]

Today my Vishay 78-HFA04TB60-N3 diodes came in from Mouser to replace the 8 standard, "M4" (1N4004 surface mount) ones on the DAC/output board. I put them in and Wow. My soundstage exploded! Wider, deeper, taller. This mod is a must. I don't know if these are the best ultrafast soft recovery diodes, but I know they are far better than stock. These are TO-220 through-hole parts I tacked down (soldered) on the pads after removing the originals, and you might instead want to use surface mount parts like the Schottky diodes used on the input/clock board (and front panel board). If you don't solder and can't tell the anode from the cathode, have Ric Schultz replace these diodes.

Next tonight, I soldered the transformer wires directly, bypassing a bunch of connectors and 2 switches. Not nearly the improvement as the diodes to my ears. For some people, it may not be worth the loss of on-off switching and 115/220 switching. For US people, wires on the IEC tabs from top to bottom are yellow/green stripe (ground), blue(2x), black(2x). Blue and black are the transformer primaries for 115v. If you reverse the blues and blacks it will sound wrong like a power plug with wrong polarity, and what I did on the first try.

Ric tells me I need to replace the clock coax cable next, either with a better cable or a clock daughter card. I bought extra diodes to replace those in every other piece of gear in my system because regular bridge rectifier diodes pollute the AC power lines going to other pieces in addition to the gear they are in.

 

[Quadman]

Mark, Have you read older posts on this forum? I went through 2 -X20U's doing Ric's level 1 mods. The second one I compared the sound to the first one which was full Level 1 of Ric's suggest mods, at each stage of Ric's mod path. These comments start around post #31, I did not begin to mod the second dac until I had close to 200 hours on it with signal. The coax cable is a huge change, even bigger than the diodes. An even bigger change is to put a clock right at the coax tower on the output board. Then, of course, the biggest change of all is to get the dac to play DSD512, which I describe a bit on this forum and in more detail on Headfi. DSD512 is where the magic happens. BUT, you need a big boy (i7-6700K) PC to handle HQPlayer at DSD512, though I did manage with my i7-4790K PC with HQP's less demanding 2s filter sets. You still have a ways to go to see what this dac is about. It is a very fun and rewarding journey.

 

[MarkK02474]

I have read through every X20 thread on every site I could find and probably have lost track of it all. I wish there were more people exploring new mods, trying them out and reporting back. Maybe diyAudio is the place for that.

What high-grade microwave coax did you use for the 100 MHz. clock?
What clock board? Link (besides the $400 Pulsar!)? Instructions anywhere for installing one?
Is a 106.25 MHz clock (instead of 100 MHz) worth a try to better handle DSD512?
Are there any components on the bottom of the DAC/buffer board? I've not needed to take mine out yet and it seems like there ought to be more/bigger bypass caps around the DAC chips.

Have you noticed / replaced the M4 diodes (D12, D13, D14, D15, D26, D27, D28, D29) on the edges of the DAC/buffer board down by the output buffers? Are they worth replacing with SMT Schottkys? Yeah, I know Lindahl transformers are the way to go, but these might be polluting power rails if on them.

I've resisted getting into the whole music server and software thing because it sounds like a longer crazier journey than soldering iron mods. $15K for a tweaked PC from Monaco? I'm also trying to be rational on investment when new DACs and CPUs come out all the time (like the i7-7700K just released). I'd like to be able to take out a $400 clock and Lindahl transformers if I put them in my X20 and use them in some future ES9038 DAC, without ruining the X20. As of now my tab is only about $20 inside and $100 for a AQ power cord.

Another challenge is the DAC sounding so good that I end up listening to it instead of putting it back on my bench! If I had a second one to leave playing while working on mods, I'd probably still get distracted by the music.

BTW, I'll try to attach a pic of my back panel which shows my mounting of the transformers using 1/4"x2" nylon bolts, nylon fender washer, and 1/8" thick rubber washer. No metal in there with two corrugated cardboard and the supplied thin rubber disk under the transformer.