DACs Galore and Expectation Bias

jkeny

Industry Expert, Member Sponsor
Feb 9, 2012
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I am using an Aurender N10 for music duties, the X20 will drive the amps direct as it has a volume control feature. I listen to a few songs with the X20 connected direct then place the preamp back in. Before the new tubes, softening and muting of details, after the new tubes more of a 1 to 1 comparison. Hope this makes sense.

Yes, it makes sense & is the outcome any different now - is there a bigger audible difference between DACs now?
 

Argonaut

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Jul 30, 2013
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I agree, a true bargain but at the cost of the unknown if future issues arise. I have not read anyone needing repairs and how this would be handled.

I am using a Tung Sol 6550 in the REF5SE and it did make a noticeable difference. Seems to run a little hotter with the Tung Sol.

Which version TS are you running with Marty? I find them to be more neutral and less 'euphonic/coloured' chronologically from early production, After expending many more hours rolling 6550's than any sane body should, I settled on the GE 6550A as the best 'All Rounder' for me.
 

nc42acc

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Nov 10, 2015
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Good question on the Tung Sol version, all I can do is give you the link of the one I purchased. I also used the Sovtek 6H30, I think they are more open and airy sounding than the DR counterparts.

http://www.upscaleaudio.com/6550-kt88-kt120-kt150/tung-sol-6550/

Which version TS are you running with Marty? I find them to be more neutral and less 'euphonic/coloured' chronologically from early production, After expending many more hours rolling 6550's than any sane body should, I settled on the GE 6550A as the best 'All Rounder' for me.
 

Argonaut

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Jul 30, 2013
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Good question on the Tung Sol version, all I can do is give you the link of the one I purchased. I also used the Sovtek 6H30, I think they are more open and airy sounding than the DR counterparts.

http://www.upscaleaudio.com/6550-kt88-kt120-kt150/tung-sol-6550/

Arggggg!!! New production, Sorry Marty but I found this one to be the aural equivalent of licking an 12 Volt battery!
Any of the genuine New Jersey production variants from the mid 50's through to mid 70's will sound noticably better in your REF5SE.

I shall have a scout around for links to dependable sources in the US.
 

Quadman

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Mar 1, 2016
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I am late to this post, but have had a Gustard X20u for 8 days now with signal running constantly and even performed a few simple mods. I have not compared this dac to anything other than my previous dac a NAD M51 which I had sounding just fabulous in my system. I bought the Gustard because of many favorable comments on it and Marty's comments were a big part of that and the ability to upsample to 2x DSD via USB. The X20 now has over 160 hours of signal running thru it and as I mentioned I did perform some basic mods, which take this dac to an even higher level, Ric from Tweakaudio.com is posting these on his site. This dac now crushes my NAD and competes with my very nice analog rig SME30mk2, sme Vd arm, dynavector XV1s cart. Marty said it well "Dac shines in minute details and depth resolution". Density of information as I call it, by that I mean vinyl can give all performers even to the sides and back a 3d, very real palpable presence. Digital usually gets that on the main performer but the side and back performers, even tho very transparent and dynamic they are always more 2d than the front lead performer. The Gustard with these basic mods now gives me that "density of information" 3d images from front to back, side to side. very transparent, dynamic and involving. I have never enjoyed music more than I do now.

So I am not surprised this dac did so well in his "unscientific" shootout. It definitely punches, way higher than it's price.
 

KLH007

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Feb 2, 2012
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I am late to this post, but have had a Gustard X20u for 8 days now with signal running constantly and even performed a few simple mods. I have not compared this dac to anything other than my previous dac a NAD M51 which I had sounding just fabulous in my system. I bought the Gustard because of many favorable comments on it and Marty's comments were a big part of that and the ability to upsample to 2x DSD via USB. The X20 now has over 160 hours of signal running thru it and as I mentioned I did perform some basic mods, which take this dac to an even higher level, Ric from Tweakaudio.com is posting these on his site. This dac now crushes my NAD and competes with my very nice analog rig SME30mk2, sme Vd arm, dynavector XV1s cart. Marty said it well "Dac shines in minute details and depth resolution". Density of information as I call it, by that I mean vinyl can give all performers even to the sides and back a 3d, very real palpable presence. Digital usually gets that on the main performer but the side and back performers, even tho very transparent and dynamic they are always more 2d than the front lead performer. The Gustard with these basic mods now gives me that "density of information" 3d images from front to back, side to side. very transparent, dynamic and involving. I have never enjoyed music more than I do now.

So I am not surprised this dac did so well in his "unscientific" shootout. It definitely punches, way higher than it's price.

Quadman, Please detail which mods you have done, bypass/change fuse, take out transformer hardware, bypass on/off switch etc.?
 

Quadman

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Mar 1, 2016
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X20u mods

Quadman, Please detail which mods you have done, bypass/change fuse, take out transformer hardware, bypass on/off switch etc.?

I mostly followed what Ric posted on his site and I believe he will post soon on a thread here. In order of importance so far: 1) bypass the fuse, wrap it in copper foil or alternatively use a very good audiophile fuse. 2) open top and remove ac lines from IEC cut off shrink and then twist them and reattach, remove ac line from digital and analog boards, cut shrink, twist and reattach 3)remove tranny bolts and nuts 4) damp big caps I used old blu-tack and cork, it may do nothing other damping products are better but its what I had. Close up and listen to new are you kidding me sound. These are very easy to do and should not affect any warranty, but really are you gonna send this back to China to get fixed should it fail?

Second round of mods a bit more aggressive 1) remove voltage selector and pc board soldered on IEC and solder tranny wires direct to IEC for 120 V; Black to N and white to L, for 220V Black to N and Red to L tape off unused tranny wire (either white or red) remove wire from front on/off knob to IEC, now only way to turn off is to unplug 2) I made wood donuts 1/4" or 6mm thick to lift tranny off of chassis 3) I used some 3M5030 emi/rfi shielding-1 large piece to cover both tranny's, 1-3"x7" piece I placed under the digital PC board, I cut a piece to shield the LED board from the digital section, I cut a piece to put between the rear of the USB card and the aluminum divider, covered a few small openings between the dividers. Thicker 3M may work better, its what I had.

There will be more Ric is working on, The biggest changes are the first paragraph the second paragraph refines it more but voids warranty and requires some soldering skill. If you do desolder the PC board from the IEC plug use a old AC cord (not plugged into the wall) to act as a heat sink. You will not be disappointed with the results.
The pics below show paragraph 1 mod and the other paragraph 2 mod.

twist ac.jpg x20 shield.JPG
 
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EuroDriver

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Sep 16, 2015
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The DAC which breaks away from the pack is the T+A DAC 8 DSD which can do DSD 512

Of course you need a software player that can deliver DSD512, and that's where HQ Player shines. However the sound quality at DSD 512 is simply stunning

Beg, borrow or build a tweaked out PC with the computing power to run HQ Player at DSD 512, and then enjoy the music
 

Quadman

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Mar 1, 2016
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The DAC which breaks away from the pack is the T+A DAC 8 DSD which can do DSD 512

Of course you need a software player that can deliver DSD512, and that's where HQ Player shines. However the sound quality at DSD 512 is simply stunning

Beg, borrow or build a tweaked out PC with the computing power to run HQ Player at DSD 512, and then enjoy the music


The Gustard can do DSD 512 via I2S, people have used the Gustard u12 or the Tanly to take usb from PC and send to X20u via I2S DSD 512; And I did see one person (on Head-fi) with a different driver get his Gusatrd to handle DSD 256 via USB. 128 sure sounds good so 512 should be really nice. My i7 only hits 12% cpu load at 128 so I should be fine.
 

YashN

New Member
Jun 28, 2015
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I mostly followed what Ric posted on his site and I believe he will post soon on a thread here.

These are very cool mods. I don't have a Gustard, but I build my own SET Tube amp and my wires are twisted internally - same thing in my DIY AC Filter/Conditioner box and in fact, even in my DIY Cables, so this was a very interesting read.

Makes me want to continue to optimise or mod my gear again. This is definitely in the works most probably as from next week as this week-end I was offered a Black & Decker Jig saw - let the DIY being again!

Hope I don't miss Ric's post. Where will we find it?
 

Quadman

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Mar 1, 2016
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@YashN Ric mentioned he would start a new thread on this forum showing his mods, not sure on his timing. He does list the ones I have done on his web site Tweakaudio.com. A big mystery to me why they would not twist AC wires which is common industry practice.
 

YashN

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Jun 28, 2015
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@YashN Ric mentioned he would start a new thread on this forum showing his mods, not sure on his timing. He does list the ones I have done on his web site Tweakaudio.com. A big mystery to me why they would not twist AC wires which is common industry practice.

Cool, thanks.
 

GUTB

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Mar 15, 2016
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Amazing claims have been made about the Gustard X20. I note that the amazing mods being worked on in the other thread that got moved have not been updated since last year -- which seems to indicate those that have been raving about it have moved on, suggesting that it wasn't so wonderful to begin with.

I mean, this is really just a Sabre / XMOS DAC right? There's no special technology, no advanced features, etc. I read somewhere where it was claimed that the unit has a SNR of 130 -- really? Can anyone verify that? That seems frankly unlikely.
 

Quadman

Well-Known Member
Mar 1, 2016
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Amazing claims have been made about the Gustard X20. I note that the amazing mods being worked on in the other thread that got moved have not been updated since last year -- which seems to indicate those that have been raving about it have moved on, suggesting that it wasn't so wonderful to begin with.

I mean, this is really just a Sabre / XMOS DAC right? There's no special technology, no advanced features, etc. I read somewhere where it was claimed that the unit has a SNR of 130 -- really? Can anyone verify that? That seems frankly unlikely.

That thread I think you are talking about was "chinese dac shames a few....." I am new here but I have heard that Blizzard, who's corner it was in is no longer on the forum, they moved it but no one can post to it. It doesn't say closed but I can find no way to post a comment on the thread. So don't take it that it means the dac is not so wonderful. YMMV, but I think it is outstanding and I am very experienced in hi-end analog (SME30mk2) and this dac with 2x DSD up sampling is rivaling that rig. I am not an engineer but it has 2 saber 9018 chips, it looks to me like dual mono one for each channel. I have seen no measurements on this dac anywhere to confirm SNR, it does have rather high output tho 2.8V rca, and 5.6 v balanced, yes I know it has nothing to do with SNR.
 

Ric Schultz

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Jun 21, 2013
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Yes, Blizzard got blitzed so his forum and threads are no more. All those that raved about the DAC are still raving but on other forums and threads.....please see my site for links to the other threads: http://tweakaudio.com/EVS-2/Gustard_X20_Mods.html

I will be outlining all the easy to do mods one at a time and showing pics on my site. I will start a thread here on the modified Gustard as soon as I have my first mods available. Meantime, you can do the DIY ones yourself.

ESS claims that mono-ing the 9018 DAC can give up to -135db dynamic range. What the Gustard measures is unknown.

By the way, the Gustard actually puts out 3.3V rca, 6.6V balanced and then can double that again and then again with the gain control (normal, +6, +12). This is measured with the original Philips Test Disc....the industry standard.
 

nc42acc

Member Sponsor
Nov 10, 2015
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GUTB I am the OP of this thread and I have moved on........


Moved on and bought a second X20 so I can try Rics mods.

Amazing claims have been made about the Gustard X20. I note that the amazing mods being worked on in the other thread that got moved have not been updated since last year -- which seems to indicate those that have been raving about it have moved on, suggesting that it wasn't so wonderful to begin with.

I mean, this is really just a Sabre / XMOS DAC right? There's no special technology, no advanced features, etc. I read somewhere where it was claimed that the unit has a SNR of 130 -- really? Can anyone verify that? That seems frankly unlikely.
 

YashN

New Member
Jun 28, 2015
951
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Canada
GUTB I am the OP of this thread and I have moved on........

Moved on and bought a second X20 so I can try Rics mods.

Haha! :D
 

Simon Moon

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Apr 24, 2015
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The Gustard can do DSD 512 via I2S, people have used the Gustard u12 or the Tanly to take usb from PC and send to X20u via I2S DSD 512; And I did see one person (on Head-fi) with a different driver get his Gusatrd to handle DSD 256 via USB. 128 sure sounds good so 512 should be really nice. My i7 only hits 12% cpu load at 128 so I should be fine.


I own one of these DACs and I'm very happy with it.

I have compared it to a couple of DACs at about twice the price. It was better in almost every respect.

It sounds great with DSD 128 via the USB input, but I sure would like to try quad DSD via the I2S input.

Please correct me if I'm wrong, but it looks like that can be accomplished with a Gustard u12 and a standard HDMI cable.

Thanks!
 

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