[Folsom]

Can anyone report what OPAMP's appear to be used in the Gustard? Perhaps it could be easily converted for rolling opamps.

[PeteG]

Can anyone report what OPAMP's appear to be used in the Gustard? Perhaps it could be easily converted for rolling opamps.

Full balance Discrete components Analog Line.

[Ric Schultz]

Sorry, no.  The output stage of the Gustard has three stages in series.  The first stage is single surface mount I-V converter op amps for each phase (AD4898-1).  Excellent sound.  You will not do better in an op amp.  Second stage is OPA 1632 differential amplifier (also an op amp).  Third stage is discrete buffer.  Changing the op amps for I-V conversion would be a waste of time.  Been there.  What you need is a fully discrete output stage....my first try will be tomorrow.  This output stage will also have its own separate regulators and power supply parts separate from those powering the stock output stage.  Hopefully, we get better sound.  The stock output stage is REALLY GREAT!

You can see two of the IV converter op amps in the fore ground in the above pic and straight back and in between the middle two red Wima caps you can see an even tinier 1632 on each channel.

[quadman]

As Ric mentioned I maybe the only person currently who has a very close to level 1 mod and did the upgrades in stages listening after each.  I also have a friends STOCK Gustard here which has been burning in for more than a week.  I can compare that unit to my level 1 unit.  Friday evening the stock X20u had over 170 hours on it, I listened to it for a couple of hours; IT is a really nice dac as it is stock and you would not think you are missing anything at all.  It checks most of the boxes Tonality, transparency, huge stage, solid palpable well defined images, dynamic and great bass.  I was enjoying it, my only concern was a very slight digititis which if you had a full SS system and brightish speakers may be annoying.  (All listening was with dedicated audio window PC i7 based, Roon and HQplayer,  AQ Jitterbug, wire world USB cable (red one), USB regen with stock PSU, Gustard.  Upsampling all music to DSD128).  Then I switched to the level 1 mod Gustard, same level and same songs that I played in the last 20 minutes.  Immediately images had tighter focus, there was more transparency (quieter background), the stage was wider and deeper, and image location was more specific.  Bass was tighter and had better definition, the air in the body of a double bass was more distinct, the softest tympani taps were distinct as individual strikes (as opposed to a rumble) and the air in the tympani kettle was more apparent.  There was a more relaxed feeling much like going from really good digital to really good analog.  It seemed like there was more energy, but my writing skills and vocabulary cannot begin to describe that effect.  Music was just more involving with the L1 X20u, more real you don't want to turn it off, just keep listening.

Now is this a night and day difference comparable to go from $300 bookshelf speakers to $10K speakers, no.  To me it is a very significant change that involves me more in the music in a way I have not been involved before.  I mentioned much earlier in this thread about a paradigm shift.  The L1 is what I talk about.  The Stock Gustard is just a REALLY nice audio component that I very happily would own and enjoy until that next great unit comes along that involves me more in the music.  The L1 does that and more, paradigm shift.  I am stunned such a modest cost unit can deliver such an experience.

I just started the Level 1 mod's to my friends Gustard.  Today I pulled the steel hardware from the tranny's and placed them up on 1/4" thick basswood.  I removed all shrink and twisted all 5 runs of the AC lines and I wrapped the fuse in copper foil.  I will report on it's progress Tuesday as my next serious listening session is Monday evening.

[jtwrace]

I removed all shrink and twisted all 5 runs of the AC lines and I wrapped the fuse in copper foil. 

[quadman]

We are free in America, that is my choice.  You can spend big $$$$ on audiophile fuse and sleep better.  Like Ric said in OVER 25 years as a audiophile I have NEVER had a SS line level item blow a fuse.  I am comfortable with this.  You are not.  We get it.

[restrav]

Sorry, no.  The output stage of the Gustard has three stages in series.  The first stage is single surface mount I-V converter op amps for each phase (AD4898-1).  Excellent sound.  You will not do better in an op amp.  Second stage is OPA 1632 differential amplifier (also an op amp).  Third stage is discrete buffer.  Changing the op amps for I-V conversion would be a waste of time.  Been there.  What you need is a fully discrete output stage....my first try will be tomorrow.  This output stage will also have its own separate regulators and power supply parts separate from those powering the stock output stage.  Hopefully, we get better sound.  The stock output stage is REALLY GREAT!

You can see two of the IV converter op amps in the fore ground in the above pic and straight back and in between the middle two red Wima caps you can see an even tinier 1632 on each channel.

Hi Ric. i have another Chincese DAC with the picture attached bellow, do you think i can the an opamp upgrade on it? I mean I know it is just a direct replacement. i want to know what to replace it with. what is the best option?

[Ric Schultz]

There is a thread on Headfi on that DAC.  One guy replaced the first op amps with Sonic Imagery 994 discrete op amps (a little over $200 the pair with shipping) and the second opamps with latest Burson V5 jobbies ($130 pair plus shipping).  He did a bunch of other tweaks as well.  Have fun!

[restrav]

There is a thread on Headfi on that DAC.  One guy replaced the first op amps with Sonic Imagery 994 discrete op amps (a little over $200 the pair with shipping) and the second opamps with latest Burson V5 jobbies ($130 pair plus shipping).  He did a bunch of other tweaks as well.  Have fun!

thanks for the heads up man, appreciate it.

[restrav]

what are those variable reisstors? i assume they set bias. would teaking them be advisable and if so how would i go about doing that. i do own a multimeter but i have no idea what to to go about it.

[Ric Schultz]

Please read the Headfi thread.  They talk about the variable resistors and changing them to expensive Vishays.

[orientalexpress]

Hi
i haven't open up mine yet,what size of Fuse doe it have?

Thank you

[PeteG]

Hi
i haven't open up mine yet,what size of Fuse doe it have?

Thank you

Small slow-blow, 1A.

[quadman]

Hi
i haven't open up mine yet,what size of Fuse doe it have?

Thank you

5x20mm, 1A, sloblow

[quadman]

I just started the Level 1 mod's to my friends Gustard.  Today I pulled the steel hardware from the tranny's and placed them up on 1/4" thick basswood.  I removed all shrink and twisted all 5 runs of the AC lines and I wrapped the fuse in copper foil.  I will report on it's progress Tuesday as my next serious listening session is Monday evening.

Last night I listened to the slightly modded dac and it has improved some (211 hours).  Tighter images, slightly quieter background, touch more transparency.  I really enjoyed listening to it.  Then I went to my level 1 dac, lets just say the slightly modded one has a ways to go before I think paradigm shift.  The next set of mods are scheduled for this weekend when I finish the AC mod (remove pc board soldered to IEC and solder Tranny wires directly to IEC, remove wire lead from IEC PC board to front pc board this eliminates the ac line filtering and on/off switch).  I will also damp the IEC with some Ear material that Ric has mentioned.  I plan to leave the fuse (wrapped) in the circuit so anyone, even me, could swap to a audiophile fuse down the road.

Next report on progress will be next Tuesday.  This is fun

[quadman]

Some exciting news over at head-fi on the gustard x20 thread, on page 48, post 712 @bitcars details how to get the X20u to play DSD256 with the DIYinHK 3.34 Xmos driver.  I followed his instructions except I turned off digital signing in Win 10.  Installation went perfectly and my first attempt to play DSD256 did not, my dac showed DSD128 but the PC's CPU was at mid 20's % so it was up sampling.  Then I re-read some of Jussi's set up notes (for HQPlayer) I had copied from other forums and he states if you have a native asio DSD driver then under SDM pack in settings you can select none (with the 3.2 driver I had selected SDM).  It worked and now the dac showed DSD256 and the CPU usage was in the low 20's.  @bitcars uses foobar and he explains how to set that up.  At last we have a driver thats lets us play DSD256 through the Gustard   I thought the sound was a step forward, not night and day, but nice.  More transparency, acoustic instruments had some extra detail (piano boards held the sustain longer, and guitars had more air inside them) Massed strings sounded wonderful.  The stage seemed larger but that may have been due to the increased transparency which made images more distinct and 3D'ish.  I was more involved in the music.


On another note I have now completed the full AC mod to my friends X20u and damped the larger caps with ear SD40al material.  This is what I would call a pretty significant upgrade getting about 85% of the full level 1 mod.  The biggest differences being a bit less transparency and size of the sound stage; also performers are not as solidly located in this stage as full L1.  Now this would not be noticeable to you until you heard a full L1 then you would begin to understand what I am saying.  If you just listened to the full ac mod with damping you would not say to yourself I wish I had more transparency and a bigger stage.  As usual you do not know what is missing until you hear it.  Friday I will remove the diodes on his output board and replace with Ric's recommendation and then probably Sunday I will solder in my custom made coax cable.  Then I only need the Quantum chips to get to Ric's full level 1 mod (they are ordered, just waiting for them).  I will report after each mod.

For those of you that only did the first 3 steps of the AC mod 1) twist AC wires 2) remove steel tranny hardware 3) wrap fuse or use audiophile fuse you are missing quite a bit by not completing the AC mod and damping those caps.

[mresseguie]

Hi, Quadman.

Thank you for the update on tweaks and their effects. As an X20U owner, I'm interested.

I'm traveling right now, so I don't even have it with me. Grr.

[quadman]

Has anyone gotten the Gustard X20u to play a DSD512 signal?  I would assume owners of the Gustard u12 should, in theory, by connecting it to the X20 via i2s connection be able to play DSD512 if the dac is in fact capable of playing DSD512.  I don't remember anyone reporting on DSD512 playback.

[sruffle]

I got the Level 1 mods back from Ric about a week ago.  For me it was easily worth the money.  Compared to my NAD M51, I am hearing more details in the music and am getting a nicer soundstage.  With the stock version I noticed that the soundstage did have more depth than with my previous DAC but that depth now seems amplified.  Issues that I had with sharpness right out of the box are gone.  All in all, I am very happy with this and recommend it.

I do have a Gustard U12 so I could try to upsample to DSD 512.  However, I don't have any software installed that will do this and am not sure that my 2009 MacMini would be up to the task.  My next step is going to be removing the U12 to see how it sounds going straight to the USB through a Regen.

At some point, I will have to get some DSD files to see what the fuss is about.   Ultimately, I do want to test upsampling to DSD and try a new setup with a better transport than the Mac (microRendu?)

[sruffle]

Sorry to follow up on my own post.  Is there somebody out there who can PM me a version of the users manual in English?  Thanks.