The (high-cap.) unregulated PSU for chipamps

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#282
That's why I always insisted that, although a chip amp, the chip alone doesn't make the amp.
Disgrace or high-end, both can be done.
Click to expand...

Couldn’t agreed more.

That's the main reason why I'm investing in a good PSU design.


Carlos, in the LM3886 datasheet, single supply application circuit, they use a capacitor(4,700 uF) on the output.
Do you use it ? Advantages or disavantages?
 
#288
XELB said:
It sounds good compared to what ?
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Whatever.
I'm not loosing my time to beat a Rotel amp.:clown:
If you are able to make a good amp out of a National chip, that's another story.
Maby yes, maby no.

XELB said:
For me a good source is vinyl! Even using a good DAC I just can’t get the performance of an Rega P4 turntable, especially in high frequencies. Because of this I asked how it handles vinyl.
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Then I must say that you ain't heard nothing yet.
I love vinyl, but I can call a good source to two digital players and one dac I have.
Extensively modified, of course.
If you want to listen to a very good (commercial) digital source, you can listen to the Linn CD12 and the Unidisk 1.1.

Rega P4?
What are you talking about?
Linn LP12, with all the extras. Not mine, though.
I have a good turntable, and a good (diy) phono preamp.
I have grown up listening to vinyl, and I never left listening.
Yes, I love vinyl.
But I still must say that you haven't heard a good digital source.

XELB said:
Because of this I asked how it handles vinyl.
Click to expand...

A good amp is a good amp, and it plays everything you throw at it.
Of course, if the source is bad, it will sound bad through the amp and speakers.
Otherwise, something's wrong.
I think it's not necessary to say more.
 
#289
Rega P4?
What are you talking about?
Linn LP12, with all the extras. Not mine, though.
I have a good turntable, and a good (diy) phono preamp.
I have grown up listening to vinyl, and I never left listening.
Yes, I love vinyl.
But I still must say that you haven't heard a good digital source.
Click to expand...

It's REGA P5 :angel:

Recently I made a comparasion of a CD source versus Vinyl.
The CD was connected to a North Star DAC.
You can find info about the DAC here http://www.tnt-audio.com/sorgenti/model192_e.html

We played a few Ella Fitzgerald/Louis music’s on vinyl and the same ones on CD.

I must say that the speakers are very, very good. They have a sensitivity of 98dB, can do more than 30KHz, and the detail is beyond imagination.(they are not mine)

I know that this DAC is not state of the art, but is a good DAC. Even so, the vinyl sounded much better 😉

The best digital source I haver heard was the Accustic Arts, Drive I. I used to test my Wharfedale speakers.
At that time I could not make a "parallel"(comparasion) with a vinyl.

I'm not saying that vinyl is better than digital!
For me the only way to test the amplifier is using Vinyl(Rega P5) becouse it plays better than the CD + North Star DAC.


We olso tested two amps.
Playing CD the diference between the two was enormous. Playing Vinyl, the diference was not so big.
I don't know if this was due to the phono preamp or the architecture of each amp.
 
#290
Carlos -

Did you calculate the snubber value for the regulated ps by using it's impedence graph in the datasheet? I wanted to try that a few months ago, but just never got around to it. The lm338 has an impedence of about 1 ohm at 100khz, and I was going to see if a snubber would take care of that.
 
#291
mateo88 said:
Carlos -
Did you calculate the snubber value for the regulated ps by using it's impedence graph in the datasheet?
Click to expand...

😱
Now you've catched me.😀
Yes, that's it.

1 ohm at 100khz, and (very important) 10 ohms at 1Mhz, and rizing up to the sky.:bawling:
The snubber will make this much better. 😉

The values are very different, though.
 
#292
XELB said:
The CD was connected to a North Star DAC.
Click to expand...

Naturally.
I knew you were not comparing to anything decent.
If that's the best reference you have, it is normal that you find such a huge gap between CD and vinyl.
Also, you may be fooled by bad CD recordings.

I do think that vinyl is superior, BUT I get as much pleasure in my system listening to vinyl, CD, (very few:dead: )SACD or DVD-A.
 
#293
That is not the best reference I have. As I told before, my reference is Accustic Arts Drive I, do you know better ? :dead: 😀

At the time I tested the Accustic Arts I could not compare it with the turntable. But this is not a comparison of vinyl versus digital!
I just use the best I have(or can borrow) to test speakers, amps, cables, etc..

Due to the Noth Star, that's why I test with the Rega P5 😉
When connected(P5) to the Jeff Rowland(not mine) music goes in to another dimension. 😎
Than I connect diferent amplifiers and hear the differences.
I think this is a good way to know where the amp quality stands.
I will not try be beat the Jeff Rowland but I will use it to know where my amp lacks. I will use it as an instrument of comparison.



Perhaps one day we will test your LM amp and listen some records 😉 I think that should be interesting.
 
#294
XELB said:
That is not the best reference I have. As I told before, my reference is Accustic Arts Drive I, do you know better ? :dead: 😀
Click to expand...

I don't know where are you trying to get.😕
I've gave you two examples of state of the art digital players, have you heard them?
It's funny when you say that CD has no treble?!
Forget it, move on.
 
#296
carlosfm said:


😱
Now you've catched me.😀
Yes, that's it.

1 ohm at 100khz, and (very important) 10 ohms at 1Mhz, and rizing up to the sky.:bawling:
The snubber will make this much better. 😉

The values are very different, though.
Click to expand...


Cool, I was hoping that this would "open up" the regulated ps. What values did you use? I was going to use a 10 ohm resistor and a .047 cap.
 
#297
First of all, can I add the snubber in the output, just for testing ?

I remember something, my speakers have one Bass connection and one High Frequency connection (Bi-connection).
On Thursday I’m thinking in add the snubber.
Since I have Bi-connections, can I add a different snubber value for the cable that goes to the high frequencies?

This is just an idea, I don’t know if it’s possible to do.
Maybe it’s an bad idea :dead: :smash:
 
#298
Easy Snubber implementation

Easy Snubber implementation


QUENCHARC, is the name 😉

It’s a Metallized Polyester Capacitor in series with a carbon composition resistor.
They say it’s an ARC SUPPRESSOR or SNUBBER NETWORKS.

The manufacture is Cornell Dubilier ( Mallory ).


More information here:
http://www.cornell-dubilier.com/mpdf/quenchframe.htm

And you can buy it here:
http://www.mouser.com/catalog/621/532.pdf






Now I ask my self, what is the advantage of two in one ?:bigeyes: Less dissipation ?
 
#300
Taking a break from the smell of soldering

work in progress
 

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