Audio-gd discrete op-amps reviewed: OPA-Earth, OPA-Moon, OPA-Sun v.2

[peranders]

Quote:

Originally Posted by majkel /img/forum/go_quote.gif This one is a smoother and fuller sounding version of the AD797. Switching from the ANZ to the BRZ series is like going vinyl instead of digital. Everything is smooth to the moment your music craves for the harsh texture like aggressive violin passages, distorted guitars, or stronger double bass phrases.

The difference between these two is only the offset voltage, otherwise the same performance. How can you recognize a DC parameter? I know that the "better" selection has a higher price. Can it be that?

 

[les_garten]

Quote:

Originally Posted by peranders /img/forum/go_quote.gif Anybody been at http://audio-gd.com lately? Closed down?

They are up. It does not take much to slam them down. I'm sure some Post-Canjam traffic will do them in.

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[peranders]

Really, not for me.

 

[peranders]

Quote:

Originally Posted by zeroibis /img/forum/go_quote.gif Sorry to hijack but this seems like a thread with a lot of knowledge on opamps in general. Does any one know ok a good opamp that has a wider sound stage then the LT1364 and that I can find in 8pin somewhere. I have been digging all over the place and so far this thread seems like the place to ask.

In which circuit have you used the LT1364?

 

[les_garten]

Quote:

Originally Posted by peranders /img/forum/go_quote.gif Really, not for me.

I've been reading it all morning, just checked it. Sounds like your issue. Actually responding faster than usual. Click on one of the Links in my sig

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[les_garten]

Quote:

Originally Posted by peranders /img/forum/go_quote.gif In which circuit have you used the LT1364?

Common Zero Headamp chip.

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[majkel]

Quote:

Originally Posted by peranders /img/forum/go_quote.gif The difference between these two is only the offset voltage, otherwise the same performance. How can you recognize a DC parameter? I know that the "better" selection has a higher price. Can it be that?

You should read the datasheets more carefully to realize it is not the whole truth. They sound obviously different and there is at least one more person in this forum who confirmed this.

Regarding the Audio-gd website, it is slow to load due to probably inefficient server. All you need is to increase timeouts for your internet connection in the OS, router, whatever concerned and be patient.

 

[peranders]

Quote:

Originally Posted by peranders /img/forum/go_quote.gif Really, not for me.

The website needs "www" also. Rather unsusual these days.

 

[peranders]

Quote:

Originally Posted by majkel /img/forum/go_quote.gif You should read the datasheets more carefully to realize it is not the whole truth. They sound obviously different and there is at least one more person in this forum who confirmed this.

It's the input bias currents also, only DC parameters as I can see it. If it really was a difference it could also be a difference between two specimens, not to types. It may be a small number with only one piece to give a statistical opinion.

 

[majkel]

There are some more restrictions, not sure it's for the Analog op-amps as well but probably for all - most first page parameters in bold are guaranteed for the better series, it's sometimes stated in the middle of the document. As well as some more explanation to the MIN TYP MAX columns which one applies to which series.
As this is an audiophile forum, I don't discuss parameters and measurements here. If there is no difference in sound, I don't report any such.

 

[peranders]

If we have the parameter "it sounds better" it's hard to argue about this, nevertheless, I notice the tweaks on CD DAC Lampucera lampizator In the industrial world it's a big no-no to have excessive leads on parts. Caps with leads more than necessary will have their resonance frequency lowered which means less effective decoupling at high frequencies. Besides it forms also antennas which radiates unwanted energy (very important in digital circuits). When you connect a good ceramics cap with a "bad" polyester you will get a parallel resonance which increases the impedance. The true tweak here is to solder a bigger ceramic cap on top of the original, possible use a surface mounted plastic cap with no leads.

Compare the PPS cap I have used at the right in the picture.
http://en.wikipedia.org/wiki/Poly(p-phenylene_sulfide)

 

[majkel]

Sorry, neither I solder with long wires, nor I use the crappy Vishay caps seen above. I keep the SMD ceramic caps to let them work and add different types of capacitors or replace electrolytics. Regarding the second picture - I have no idea what you're trying to show. Two transformers very close to each other, four mediocre electrolytics and a capacitor desert around the rest of the components.

 

[peranders]

I wanted to show the PPS caps at the right in the picture.

(Just wondering: How do you know that the electrolytics are mediocre?)

 

[majkel]

By the brand - I can't read it, and look. The higher are supposed to be Rubycon, YXF, YXG (well, OK but nothing special) or YK, ZL (blah!). The smaller - violet means low temperature range, until 85 C and standard use. No idea about the manufacturer.

 

[peranders]

I'm afraid, lot's of speculations. Both types or not general purpose types and the brands are....? You can read the brand on one cap but the other one knows only I. I have dug quite much how electrolytic caps are made, material, chemistry and technology. So much I can say, they are more alike than you think when it comes to similar basic properties. You can't tell from the colour of the sleeve which properties the cap has.

I had a professional problem in reliability of a certain brand.
diyAudio Forums - Failure in a huge capacitor board - Page 1

I can say that much that Rubycon has a good quality when it comes to lifetime.