Don´t waste time with changing op-amps

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irgendjemand

Member
Joined 2007
Who is crappy here? The Amplifiers?

The real problem might be different:

John007 said:
Price of Burson Discrete Opamps is 2x price of the whole DAC.
:bigeyes:
Click to expand...

So you are expecting from a US$ 40,.- DAC to be true High-End, to have first-class resolution, and you believe that this already gives you the right to criticise Analogue Devices...

You are complaining here about the LME49720 or/and about the NE5532, and then, based on your “DAC” you come to razor-sharp conclusions. Wow!

Sorry, I can’t agree with your conclusion about “crappy amplifiers”, neither of any of your other comments. Something is crappy here – but not the Amplifiers.

By the way: The LME49720 is much better OPA then you think and better you trust that the people by Analogue Device do hear well. The 5532 is a very clean, almost synthetic OpAmp, not the best one for High-End, but if you can’t hear a difference between NE5532 and LME49720, well, I think that you are not very helpful, putting it cautiously.

I truly appreciate the good mood & willing to help of the wonderful members here, however.

Good to know that you are happy with the BB OPA604; no one wish to suppress your happiness. Can a OPA604 really sound? OK, I will leave this now. It is wonderful goal, to get the DAC as cheap as possible; we all support this, I believe. It is just that I find your pretension, let’s say it once in your country-language: To ye Špatni.
 
J

John007

Member
Joined 2002
irgendjemand i live in Czech republic, post komunism country, if i live in Germany i won´t buy cheap chinese DAC but Rotel CD player. I don´t know what you are resolving, from German peaple i don´t take criticism, In Germany you can´t do quality Hi-Fi. My ordinery Delco radio in my Olds from 85 sound much much better than your crappy stereos in Mecredeses. Your Visaton speakers are cheap chinese speakers, I have bought Visaton TW6NG tweeter in Germany for 15 Euros, i have seen exactly same speaker in my country for 2 euros. LME49720 is crappy opamp, let your ears clean.
 
A

Andy Bartha

Member
Joined 2004
You could use a resistor for the I/V and then go to a nice 1 to 4 stepup transformer. There are several very good transformer winders in Europe that sell these type of transformers, Lundahl and Sowter, are just two. Since you do not like op amps I found this to be one of the better sounding solutions. This solution is more expensive but it sounds the best to my ears.
If you like the 604s you will be amazed by the 4562s. Try them also.
 
Tolu

Tolu

Member
Joined 2007
:bawling: :bawling: :bawling:

I think someone with your experiences and audio knowledge should return to communism. :devilr:

Someone who prefers 85 Olds and compare it with Mercedes van should stay with 2 € tweeters.

I am glad that I have chassis of a german manufacturer but for one of my tweeters you could buy 140 of yours in your country. And I am glad too to drive a 06 BMW than an Olds. :cool:

If you disregard german products why don't you buy czech ones. :whazzat: E. g. take a look at KR audio in your town. You will get nice amps for about 7,000 € fromf them. :D
 
weissi

weissi

Member
Joined 2002
Conclusion here: What's crappy is the implemention in where the opamp is used, not the LME49720, nor any other high priced opamp...
If that would be so easy :rolleyes:

Especially with a DAC using TDA1541. Everyone with experience will tell you that they sound much better with alternative I/V conversion, be it passive or with discrete devices. Go to Pedja Rogic's site, there's a bunch of information about this DAC-Chip and how to make it perform.

Don't waste anymore money on technologies like opamp I/V that are already at it's boundary performance wise. There are schematics for I/V with a handful of BC550s, Cheap enough? OK, I understand that you don't want to modify your PCB to much, but then....

Edit and off Topic: As you seem to have a lot of knowledge in tube Amplifiers, I have here an old Czech tube guitar amplifier called Attack Power. Using 3x ECC83 and 2 EL34. Do you have any information about Czech guitar amplifiers? Would be nice to hear from you!

Cheers, now I take a Budvar :drink:
 
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irgendjemand

Member
Joined 2007
Pilsner is great

Hi Tolu,

Don’t be so crud (even though I don’t believe that John will ever stop).

Are you sure that he is a real Czech? Whenever I am coming to Prague, I always have the feeling that the people there are interested in taking money from the German tourists, nothing more. So, if John would have been a real Czech, he must have had enough money for Mercedes or BMW by now, or at least for a good German HiFi (must NOT be too expansive!).

By now I am sure that John believes that the German people are rich & disgusting.


Hi John,

You don’t take criticism from a German person? Pity! May be you would have learned something from them. By the way, I am not German... I do not drive German car either. You will be surprised.

Other bad news for you: The Germans are having absolute fantastic HiFi. You could have learn from them, a lot.

Thanks for the fun, even if it will remain quite gloomy for everybody here.

But as you said, the Pilsner is really great, so may be we did learn something from you here ;)
 
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Andy Bartha

Member
Joined 2004
You could go from the I/V converter to the pre amp via the DAC outputs but I wouldn't recommend that course for many reasons. Not the least all that inteconnect and connections. Any improvements would be swamped by the interconnect to the pre amp. The best and simplest solution is the output transformer. Do google search for K and K audio and look at there dac kits with the output transformer. They have nice write up and the transformers are fairly simple to install.
 
Tolu

Tolu

Member
Joined 2007
John007 said:
"The Germans are having absolute fantastic HiFi" ha ha which? Denon:D I drove American cars not German crocks.:smash: We like German peaple we always hijack you.
Click to expand...

Oh, now I know where he got the OPA2604 so quick! From the EEG he is strapped on! :dead:

Sorry, I have to leave this thread because I am whether a psychatrist nor a victim.
 
R

Radioman62

Member
Joined 2005
binatech.se/hem
KP11520 said:
John007,
With PS caps and decoupling caps both, they affect how much power you have stored for big passages of music. If they don't store enough power, Bass can seem weak, sloppy, etc. If they are too big, the highs are weak, out of phase or worse. So the right one is important. And then there is bypassing and that is another avenue.
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You don't have the knowledge KP11520, I'm sorry.

To large decoupling caps in the PSU can never degrade the audio frequency in the way you say, I'm sorry, I don't give you a chance to save your face, but the capacitors at the PSU can never be to large when it comes to sound ... maybe when it comes to the diodebridge current availability. :)

You have had some information misaligned. The sound gets out of face because the PSU capasitors are to large? ... sorry no way, Where is your very controversial statement and tests written?
The any way capacitors can get some phase alignment is in the audio line.And you should allways think of the one tenth's of OP's an hundreds of capacitors that has allready benn in the source before you listen to it ... he he :D Something for everyone tweaking.

Forgive me but I couldn't aloud to let this trough. There is some really noobs around that needs first hand information.It's not your end player that makes it all
 
weissi

weissi

Member
Joined 2002
No, Radioman62, YOU are wrong (or at least as unexactly as KP11520 was). It depends on 1,10,100,1000, etc....

Is there one main capacitor with 10.000uF, or 10x 1000uF ? There's a huge difference in the frequency domain, even if both are 10.000uF. And DAC's are said to need a lot of energy in the region of 2-3MHz. Of course, electrolytics are a bit away from this region, anyway.....

Next, what regulators are used? Isn't their PSRR frequency dependent? So whats the point using a fat 10.000uF, that gives up beeing a capacitor at ~100kHz?

And seriously, if you state that you have the absolute truth... sorry man. I'm not an expert at all, but I'm aware of SOME of the problems in designing electronics. This is why I have the greatest respect of real experts (there are quite alot in this forums).

Be more specific, or you'll get the same rough answers you're posting here!
 
KP11520

KP11520

Member
Joined 2007
Just to let you understand when I made that statement, my little brain was already thinking about bypassing with smaller caps to assist the fast transients and didn't look at the whole of the statement. I was deciding if I wanted to explain my limited knowledge about bypassing. You can see what I decided to write about that. I needed to broaden my myopic view to ensure its accuracy. New guys don't need mistakes like these. This bypassing thing seems to be a bit of an art!

All I can say is "Won't happen again," I hope. Until next time at least! LOL

Regards//KP
 
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