[brunk]

   
OPA is based on IC, therefore it has bad quality inside as well mentioned here:
http://bursonaudio.com/about-us/no-to-ic-opamps/
 
Once you compare OPAs with discrete components (I did) there is no turning back.
 
I tested a lot OPAs with discrete components before (while doing Xonar STX mod), and the one to sound terrible was always with OPAs.  Did you really compared (heard) them?
 
And no, I'm not planning to use Burson for this project.
 
You call "DIY standard" as something bad and not for "commercial devices", but keep in mind the very same USB to I2S used on DA8 did come from DIY:
http://www.diyaudio.com/forums/vendors-bazaar/216474-usb-i2s-384khz-dsd-converter.html
 
Official site:
http://www.amanero.com
 
I know test equipment costs a lot, but you can always rent them for a project or two, or buying 2nd hand (sometimes can saves a lot).

I think you're passing judgement off narrow experience. First, the Asus STX is hardly the last say in opamps vs. discrete, and varies from application. Second, you have the term "DIY Standard" misunderstood. Commercial goes through much, much more testing and R&D than DIY. There are licenses, bills, employees, equipment, advertising etc. to pay off too. It's also not about using a component that is available through "DIY channels", nearly everything is. If you want to build an equivalent DAC to the DA8 in your own home for $700, then good luck, but please stop complaining about a product that is well-designed, and excellent SQ, without even owning it. Thanks.

 

[mrcasey]

+1

 

[Jd007]

I have plenty of respect for Burson and their products, but that page on IC vs discrete opamps is quite outdated/misleading on many fronts IMO.
 
General purpose IC opamps may have been lower quality than what you can achieve with discrete circuitry many years ago, but the fact is, the technology has advanced so much since then. Nowadays most DACs/amps use special high fidelity made-for-audio opamps, which can actually measure orders of magnitude better than discrete implementations. I'm sorry but when it comes to individual components in a DAC/amp, I trust measurements more than anybody's ears.
 
IC opamps are chemically formed and hence inferior? How do they think transistors are fabricated (yes even the discrete ones), if not through a chemical process with semiconductors? It certainly isn't magic.
 
Regarding the USB board, yes it is quite a popular DIY USB converter. According to Yulong, it was actually co-developed by Yulong and Amanero, and the one in the DA8 is customized though I'm not sure what that means (it may be different from what you can buy straight from Amanero if you DIY).

 

[brunk]

  I have plenty of respect for Burson and their products, but that page on IC vs discrete opamps is quite outdated/misleading on many fronts IMO.
 
General purpose IC opamps may have been lower quality than what you can achieve with discrete circuitry many years ago, but the fact is, the technology has advanced so much since then. Nowadays most DACs/amps use special high fidelity made-for-audio opamps, which can actually measure orders of magnitude better than discrete implementations. I'm sorry but when it comes to individual components in a DAC/amp, I trust measurements more than anybody's ears.
 
IC opamps are chemically formed and hence inferior? How do they think transistors are fabricated (yes even the discrete ones), if not through a chemical process with semiconductors? It certainly isn't magic.
 
Regarding the USB board, yes it is quite a popular DIY USB converter. According to Yulong, it was actually co-developed by Yulong and Amanero, and the one in the DA8 is customized though I'm not sure what that means (it may be different from what you can buy straight from Amanero if you DIY).

I agree, I was going to mention if the whole "discrete thing" was based off 70-80's tech lol, but you got it covered 

If you look at the Amanero website, you can work with them to create custom-tailored drivers for your application, which ironically is something a typical DIY'er doesn't have access to because it requires an order that is typical for a company.

 

[Jd007]

Originally Posted by brunk /img/forum/go_quote.gif
 
I agree, I was going to mention if the whole "discrete thing" was based off 70-80's tech lol, but you got it covered 

If you look at the Amanero website, you can work with them to create custom-tailored drivers for your application, which ironically is something a typical DIY'er doesn't have access to.

Yeah I'm not sure if Yulong got a slightly modified (hardware-wise) USB board from Amanero as they do work pretty close together, or if it's just a custom driver.
 
And just to add/clarify, I'm not saying that there is no place for discrete circuitry anymore. When you want to realize your own (or someone else's) custom circuit design, obviously you can only go discrete (unless you own a fab I suppose, as it's very expensive to get small orders from a contract fab, you'll be piggybacking on other's prototype wafers). Or for amplifiers dealing with larger amplification signals, discrete components could offer better cooling as it has massively larger surface area (however this is hardly the case for DACs when the output is usually ~2-3Vrms tops for SE).

 

[pila405]

I've received an answer from Yulong regarding more extensive and rigorous testings of the amplifier, and he replied the following (I think it was translated with google translate, so I had some hard time trying to understand it)

The original mail in English:
"Thank you, published ok, indicating that the measurement conditions on the line, 
Our test equipment is being carried out in batch testing products, The short term, there is no time for rigorous measurement.
Our product research and development, has the full rigor of the tests. amp just does not publish detailed tests to the public"

 

[Esprit]

  Official site:
http://www.amanero.com

Amanero srl (srl means "limited") isn't a DIYer! This is their VAT number: 02001290507 and they are in the same city of M2Tech http://www.m2tech.biz

 

[Priidik]

  My unit consumes three times as much. Has someone verified this value?

I  measured current and voltage with high-end RMS multimeter (0.5% RDG accuracy on both voltage and current) and got around 20W depending on amp load.
Still never exceeding 30W mark.
These socket mount readers aren't very trustworthy. If it is  based on current clamp design, then it should be pretty inaccurate on small currents, i think.

 

[teiki arii]

  I have plenty of respect for Burson and their products, but that page on IC vs discrete opamps is quite outdated/misleading on many fronts IMO.
 
General purpose IC opamps may have been lower quality than what you can achieve with discrete circuitry many years ago, but the fact is, the technology has advanced so much since then. Nowadays most DACs/amps use special high fidelity made-for-audio opamps, which can actually measure orders of magnitude better than discrete implementations. I'm sorry but when it comes to individual components in a DAC/amp, I trust measurements more than anybody's ears.
 
IC opamps are chemically formed and hence inferior? How do they think transistors are fabricated (yes even the discrete ones), if not through a chemical process with semiconductors? It certainly isn't magic.
 
Regarding the USB board, yes it is quite a popular DIY USB converter. According to Yulong, it was actually co-developed by Yulong and Amanero, and the one in the DA8 is customized though I'm not sure what that means (it may be different from what you can buy straight from Amanero if you DIY).

Hello everybody,
I have tried the first Burson products in 2006 and audio-gd products as well (I still own one of the first FBI-500 ever made stil working). I had tried an integrated burson and audio-gd OPA in my gears with success. I have tried a lot of IC-OPA in my Cayin CDT-17A and none were as good as AZP ones. When I read: "this IC-OPA is an oustanding audiophile one, one of the best ever heard", let me smile (grin). Yes, there are good but all "coloured", but once you have "heard" AZP discret OPA, you don't want to go back to IC-OPA. 
I changed all IC-OPA in my Cayin (4 double OPA and 4 single OPA for real symetric outputs) by AZP Discret OPA with success :
 

 
 

 
 

 
 
I have done the same with my Sony SCD-XA5400ES (2 double OPA2134 for I/V Conversion and 2 double NJM2114 for low-Pass filtering since the Sony player octo-upsamples CD and plays native DSD thanks to CXD9927 working with BB DSD1796DBR) for real symetric outputs. And again, we enter in "another world" of Hi-Fi, sorry to say that.. 
Antoine, the conceptor engineer in Audio Pro who realised the OPA is working on Yulong DA8 actually. So let us be patient. I'm never sure it works, but it did until know. 
 

Architecture

 - Paire différentielle d'entrée sur JFET faible bruit 2SK170 et charge active (miroir de courant) avec bipolaires faible bruit
 - Etage de gain et abaisseur d'impédance en pure classe A, transistors bipolaires faible bruit
 - Sources de courant à fort CMRR (une par étage) compensée en température (+0.6µA/°C) et compensées en tension d'alim (+6µA/V)
 - Découplage d'alim local de chaque étage par capa MLCC faible ESR
 - Filtrage d'alim global avec ferrite + capa "3-terminal" (capas de dernière technologie ultra faible ESR en HF)
 - Toutes résistance Vishay Dale CMF55
 - Seulement 4 transistors sur le trajet du signal
 - Circuit imprimé double face professionnel, cuivre 35µm plaqué or, vernis épargne rouge, dim. 26x40mm
 - Pinout compatible AOP simple et AOP double avec le même circuit imprimé
 - Soudure étain/argent
 

 
 
 
Performances
 
Alimentation max : +/-23V
Tension de sortie max en fonction de la charge :
- 11.5V crête @ Rc = 1k ohms
- 8V crête @ Rc = 630 ohms
- améliorable par simple réglage du bias du dernier étage (dans la limite de la dissipation max)
Tension de sortie max en fonction de l'alim :
- 12.8V crête @ +/-15V
- 17.8V crête @ +/-20V
- 20V crête @ +/-23V
Slew-Rate : 38V/µs, amortissement rapide sans trainage

 
 
Offset : +/-0.5mV typique, ajustable par trimmer 25 tours.
Bande passante (suiveur) : de 1Hz à 1MHz dans +/-0.1dB (coupure a 750kHz avec un gain de 11 en non inverseur)
THD :
- inverseur gain unitaire : THD -100dB (limite absolue du système de mesure), SNR 136dB (dynamique max du système de mesure)
- inverseur gain 2.2 : THD -99.6dB, SNR 134dB.
- inverseur gain 10 : THD -94.5dB, SNR 133dB.
Stable sur charge capacitive.
Stable au gain unitaire.
Tous transistors appairés sur un outil conçu et développé spécialement pour ce projet. Transistors appairés sous leur Vce et Ic effectifs dans les AOPs.

 

 

[Esprit]

  I  measured current and voltage with high-end RMS multimeter (0.5% RDG accuracy on both voltage and current) and got around 20W depending on amp load.
Still never exceeding 30W mark.
These socket mount readers aren't very trustworthy. If it is  based on current clamp design, then it should be pretty inaccurate on small currents, i think.

All my other measures seem correct. 
P.S. My DA8 works with 230V

 

[Priidik]

  All my other measures seem correct. 
P.S. My DA8 works with 230V

I'm in EU aswell, so 230V. Although voltage shouldn't matter too much.
I'm not familiar with the protection circuitry inside DA8 in the psu side, but maybe you have some ripple supression module gone bad.

 

[Clemmaster]

Received my DA8 (silver) today at work. Got it from Grant fidelity.
It seems the LCD screen is not connected properly: only the volume bar is displayed, on a light background.
I have no text information so I have to operate the unit blindly. When I press the screen, the sample rate appears on the top right corner, with a dark background.
 
Right of the bat, with my RE-262 plugged in the headphone output, I find the sound is thin. It is brighter than the Dangerous Source, has a good sense of details and transparency but the tonality is off.
It is much better with the Focal Spirit Pro (which in turn sounds slightly too dark on the DS).
 
The RE-262 is 150Ω; it has been said the amp does not do really well with high-impedance headphones but I still find it weird, the RE-262 is not what I'd call a tough load.
 
The unit is brand new and I obviously have no idea what filter settings I'm using (my guess is slow mode) but I was expecting a better performance (from the headphone out) and a much better quality assurance (a screen issue is easy to spot).
 
Update 1: after 1h of casual listening (at work), I can say the DA8 is very communicative - as in involving -, I like that aspect very much! At first glance, it seems more detailed than the Dangerous Source and the separation is definitely better (especially on both sides of the sound-stage - where sounds tend to be fuzzy on most DACs for me).

 

[brunk]

  Received my DA8 (silver) today at work. Got it from Grant fidelity.
It seems the LCD screen is not connected properly: only the volume bar is displayed, on a light background.
I have no text information so I have to operate the unit blindly. When I press the screen, the sample rate appears on the top right corner, with a dark background.
 
Right of the bat, with my RE-262 plugged in the headphone output, I find the sound is thin. It is brighter than the Dangerous Source, has a good sense of details and transparency but the tonality is off.
It is much better with the Focal Spirit Pro (which in turn sounds slightly too dark on the DS).
 
The RE-262 is 150Ω; it has been said the amp does not do really well with high-impedance headphones but I still find it weird, the RE-262 is not what I'd call a tough load.
 
The unit is brand new and I obviously have no idea what filter settings I'm using (my guess is slow mode) but I was expecting a better performance (from the headphone out) and a much better quality assurance (a screen issue is easy to spot).
 
Update 1: after 1h of casual listening (at work), I can say the DA8 is very communicative - as in involving -, I like that aspect very much! At first glance, it seems more detailed than the Dangerous Source and the separation is definitely better (especially on both sides of the sound-stage - where sounds tend to be fuzzy on most DACs for me).

Did you double check the voltage selector on the back for proper setting?

 

[Clemmaster]

  Did you double check the voltage selector on the back for proper setting?

 
It came saying 230V. I switched it to 115V.

 

[brunk]

   
It came saying 230V. I switched it to 115V.

OK. Well, welcome to club!

I'm sure Grant Fidelity will take care of you promptly. Never heard of anyone with screen issues before, but there's always a first for everything.