NJL0281 and NJL0302

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Charles Hansen said:


I'm not so sure that this is real or just an error in the data sheet. I believe that both parts use the same die inside and the only difference is the size of the package. One has the larger TO-264 package and the other has the smaller TO-247 package.

Mr. Hansen,

Both parts use the same TO-246, 5 lead case 340AA but the chip inside is very different ... only the thermal track diode is the same.
http://www.diyaudio.com/forums/attachment.php?s=&postid=1349161&stamp=1194858226
I've try both njl3281/1302 and njl0281/0302 in my amp. The "zero"version sound more smooth, more precise on highs, with no harshiness or sibilance. There is nothing wrong with the other version (3281/1302), but I prefer the "zero" version.
This is the schematic.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=111756
Regarding an old discussion about thermal stabilization method, it is not so difficult to implement a very simple method once you know the TC of the diodes and have all output stage transistors, including drivers and predrivers, on the same heatsink

Mihai
 

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roender said:


Regarding an old discussion about thermal stabilization method, it is not so difficult to implement a very simple method once you know the TC of the diodes and have all output stage transistors, including drivers and predrivers, on the same heatsink

Mihai


Just as a point of reference, Bob Pease wrote an article "What's all this Vbe stuff" -- http://www.national.com/rap/Story/vbe.html

If you folks want, I'll carry the devices on my webstore at just enough markup to pay for shipping from DK, but I am not going to get stuck with hundreds of them.
 
i will need those transistors in January but more probably in February....
and i plan to make at least three amplifiers based on Roenders design (one for me and two for my friends)...i am very impressed with the design....but we lack in money (all three of us) so we will progress slowly....
i was looking for a suitable source for the devices in case some of us can't go together with the others related paying for stuff.....that is why i needed a source that is able to send me six by six devices or something - but not 25 of them that digikey can do....
anyway - i think it will be digikey afterall....so jackinnj i think that You do not have to bother only because of me....
i wonder how many guys are here interested in Roender design... if we can go together than maybe you can see how mana of the transistors are needed and make your order at ONsemi or somewhere .... for sure at the end i will need at least 18+18 (for three amps)...but i am not sure about the speed of buying...that is the real problem....
 
Sparkle,

I don't want to influence you in your decision, IMHO this is an amplifier which worth some financial efort - you will be rewarded with a warm and pleasant sound. DIY does not mean, in every cases, as little money as possible ... this was not one of my goal when i designed it, but contrary.
I'll recommend you to buy at least double the number needed of output devices and try to match them as close as possible.
The output stage is very critical and deserve much more attention, it will make the difference between a nice and an excellent sounding amplifier.
http://www.diyaudio.com/forums/showthread.php?postid=1351876#post1351876

Mihai
 
roender said:
Both parts use the same TO-246, 5 lead case 340AA but the chip inside is very different ... only the thermal track diode is the same.
http://www.diyaudio.com/forums/attachment.php?s=&postid=1349161&stamp=1194858226
I've try both njl3281/1302 and njl0281/0302 in my amp. The "zero"version sound more smooth, more precise on highs, with no harshiness or sibilance. There is nothing wrong with the other version (3281/1302), but I prefer the "zero" version.

Thank you for the correction. I don't understand why On Semi makes two parts with such similar specifications. It seems the only differences are the power (180 watts versus 200 watts) and the Cob (400 pF versus 600 pF). I will contact them to find out why they make two parts that are so similar. When I receive an answer I will post it here.
 
roender said:
Sparkle,

I don't want to influence you in your decision, IMHO this is an amplifier which worth some financial efort - you will be rewarded with a warm and pleasant sound. DIY does not mean, in every cases, as little money as possible ... this was not one of my goal when i designed it, but contrary.
I'll recommend you to buy at least double the number needed of output devices and try to match them as close as possible.
The output stage is very critical and deserve much more attention, it will make the difference between a nice and an excellent sounding amplifier.
http://www.diyaudio.com/forums/showthread.php?postid=1351876#post1351876

Mihai
Hi,
for a single pair output stage, what parameters should be matched?
And how closely?
 
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