diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Digital Source (http://www.diyaudio.com/forums/digital-source/)
-   -   1541 / 1543 wake up ! (http://www.diyaudio.com/forums/digital-source/31819-1541-1543-wake-up.html)

Bernhard 7th April 2004 08:57 PM

1541 / 1543 wake up !
 
Hi,

every single chip has got very different distortion.

They all sound different.

Even left / right channel. :(

I just put opa2604 in place of NE5532.
Not a big change compared to putting another 1541.

IMHO reclocking, video-opamps in output stages and stuff like that won't cure anything.

Also no wonder that one likes 1541, another 1543, it depends on the chip you have.
It may sound good or bad.
Even if you have a few they all may be bad.
Sorry :cannotbe:

Bernhard

till 7th April 2004 09:02 PM

Bernhard, dont kill their illusions. They might stop buying expensive S2s or antimagnetic I/V resistors!

Bernhard 7th April 2004 09:05 PM

Another thing:

Non oversampling gives much higher distortion.

till 7th April 2004 09:10 PM

sure, have a look at a "sine" of 20 kHz. Guess how it looks? Now look at the waveform coming out of your speaker with a mic in front of it. How does it look now?

jean-paul 7th April 2004 09:18 PM

I really don't want to react to the cartload of threads you open with the truth but this is old news so I think I should react.

Pre 1989 TDA1541(A) had quality problems, later production was more consistent. 1985 non A versions are famous for bad quality. Fact not fiction. I avoid the older versions. It was at that time a real challenge to produce 16 bit chips. One of the reasons I avoid the non A versions is that they suffer a lot more from quality problems as the A versions.

This information is here and on the web, you should not believe what I say. It also depends if you use old used chips ( especially desoldered ones ). TDA1540 ( 14 bit ) is even known for wearout. After years of service they started distorting at power on. Earlier TDA1541's also failed more than normal, please read the service bulletins for that. I strongly suggest to treat them ESD safe although they're produced in bipolar technique and don't heat them up too long while soldering. Then leave them where they are. Wearing a wrist strap won't hurt you and the chips. Same goes for PCM63 that is even more sensitive. Why Bernhard do you think new unused S1's are becoming more and more expensive ?

I don't hear the extreme differences you describe with the more recent TDA1541A's I have. Only the S2 is *much* better than the others but it was produced at the end of the series ( 1997 ) at another production line. One can assume and experience that they knew at that time to produce them consistently. As a sidenote: I just yesterday read a story that I think was given here in a thread about technicians that had problems with linking SAA7220P/B with TDA1541A ( old story but very interesting ) and made some circuitry in between because in their opinion the two did not match although they were designed for eachother. The importance of the routing of the datalines was discussed. Too bad I don't remember which thread it was. These are sensitive chips, try shielding them and see the difference on your measurement rig. It's old technique of the beginning of the cd era so what does one expect ?

We know about higher distortion with non os. Higher distortion but lower influence of jitter. What's better ? And more important, the human ear is the final judge not the instruments. I heard low jitter high bit systems with technically much superior chips that sounded absolutely worse. What is it that you want to prove ? That we are all using inferior chips that are liked so much because they distort so much ? That the chips are not all the same ? Nothing is perfect, be it chips or ears. It's the experience of enjoying music, whether it has some minor distortion or not. And of course the chips differ, they're bipolar and old technique as explained. Compare it to the tube guys that do tuberolling.

stefanobilliani 7th April 2004 09:33 PM

Hi ,

from the sinewave point of view , 1543 or 1541 in non os and single ended mode are both the same , they presents audible distorsions already at 15.5kHz .More than something is better in balanced mode wich I prefear.By the way is not a sordid sinewave that I am going to listen to - hopefully - music differs from it .
I/V conversion:
till ,
I have just implemented the Pass D1 at the 1541A and I am pleased with the results, even without the output buffers - it simplify the building life- the 1541A performs an round sounstage , defined very well from left to right ,high enough in a natural way , and ... above all ,the dinamics are not compressed in the bottom end with a clear and relaxed midrange .
I prefear the D1 above all I/V resistors and gainstages while it seems wasted with the 1543 .
Next step will be the balanced version for the 1541A.

Also 1543 sound more and more good in balanced mode: certainly if one pretends to use op amps and convert the balanced signal into single ended , the effort is lost .
To achieve the best from a balanced dac it is necessary to have after it a balanced circuitry .
********************

Regarding differences between channels 1543 is a champion expecially in volume , but the difference is coherent at the voltage level before the caps , and I find the cure in a trimmer .

till 7th April 2004 09:51 PM

Quote:

I have just implemented the Pass D1
I have only built a D1 for tests p2p, not connected to any Dac now.

Do you have pictures or PCBs ? Do you plan a PCB for the balanced version?

Im still at collectiong parts, most are here now.

Bernhard 7th April 2004 09:52 PM

Quote:

Originally posted by jean-paul
the cartload of threads you open with your truth

I apologize for that.

And I know, truth hurts.

Quote:

Originally posted by jean-paul
Pre 1989 TDA1541(A) had quality problems, later production was more consistent. Fact not fiction. I avoid the older versions.
Ok, I have another image.

My 1541 A S1 are all from 96 and all very different.

Quote:

Originally posted by jean-paul
It also depends if you use old used chips ( especially desoldered ones ).
Some desoldered chips measure very good and also sound like that.

Quote:

Originally posted by jean-paul
Only the S2 is much better than the others but it was produced at the end of the series ( 1997 ) at another production line.
I should order one.

Quote:

Originally posted by jean-paul
What is it that you want to prove ? That we are all using inferior chips that are liked so much because they distort so much ?
I don't know what chips you have.

Just I feel it is very important to know how the harmonics are distributed.

Philips may have stamped a chip with a crown, that has a low total THD, but that very THD may consist of very dominating 5th order harmonic solely :dead:

You will hear that.


I had just tested the new old S1 with opa2604.

Now after 1 hour I changed to NE5532 and restarted the analyzer.

Every single harmonic up to the 9th is within 0,2 dB compared to the opa2604.

All sound character belongs to the TDA chip.

jean-paul 7th April 2004 09:59 PM

Quote:

And I know, truth hurts.
I think your truth does not hurt anyone but yourself.

There are some factors to consider, did you measure/listen them all at the same time with the same setup ?

Were the S1's all new or from a used cdplayer ? If they are all new and from the same date, do they differ much in the same setup ? Of course they do differ, no need to discuss that as I tried to make clear in my post. The question is how much.

Quote:

Ok, I have another image.
You can have another image but I changed enough TDA1541 non A versions because of defects like one channel distorting or dead. Quality is not about sound alone, it is also meant in the sense of how much they break down or have inconsistent variation within one batch.

Quote:

All sound character belongs to the TDA chip.
We know that it is responsible for a large part of the results ( otherwise is would not be used so much I guess ) and the difference in chips but the extremity in difference in testresults of one batch are suspicious. BTW, do you have any numbers so that we know what we are talking about ?

Bernhard 7th April 2004 10:07 PM

Quote:

Originally posted by jean-paul


I think your truth does not hurt anyone but yourself.

There are some factors to consider, did you measure/listen them all at the same time with the same setup ?

Were the S1's all new or from a used cdplayer ? If they are all new and from the same date, do they differ that much in the same setup ?



Yes, all in the CD880 and I can repeat measurements as often as I want, the result is always the same.

Also from listening.

Best sound comes from chips with evenly distributed harmonics.
Even if the total is higher.

Sound that is not so good, comes from chips that have extremely low 2nd and 3rd order.

Copy from edited post:

I had just tested the new old S1 with opa2604.

Now after 1 hour I changed to NE5532 and restarted the analyzer.

Every single harmonic up to the 9th is within 0,2 dB compared to the opa2604.

All sound character belongs to the TDA chip.


7 S1 are new and have same date code, one S1 is desoldered from the CD880 and one S1 is desoldered from another CDP.

Further tested 1 1541A and 3 plain 1541, all desoldered.

But, believe me, I don't rape the chips.

Every pin is heated for 2 seconds only.

Only the S1 from CD880 with double layer pcb, that was a fight :devilr:

And this one got very good results.


All times are GMT. The time now is 09:57 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2