Hello all,
A quick question.
Would the MJL21194 or MJ15003 be a more linear device at class-a bias currents over 1.5 amps? I note that the datasheet for the MJL21194 shows the linearity dropping off over 1.5A at higher temperatures, however I have been unable to find a sufficiently detailed datasheet for the MJ15003.
Is there any other reason why one is better than the other in your opinion? One advantage of the MJ15003 is a higher SOA and power dissipation, but the flatpack packaging of the MJL21194 is also a big positive in my opinion.
I currently run MJL21194s in my JLH at 1amp bias and they sound great, but I want to wind the bias up to 1.5-2 amps while still only using single output transistors. Maybe the MJ15003 would be better for this?
Thanks,
Greg.
A quick question.
Would the MJL21194 or MJ15003 be a more linear device at class-a bias currents over 1.5 amps? I note that the datasheet for the MJL21194 shows the linearity dropping off over 1.5A at higher temperatures, however I have been unable to find a sufficiently detailed datasheet for the MJ15003.
Is there any other reason why one is better than the other in your opinion? One advantage of the MJ15003 is a higher SOA and power dissipation, but the flatpack packaging of the MJL21194 is also a big positive in my opinion.
I currently run MJL21194s in my JLH at 1amp bias and they sound great, but I want to wind the bias up to 1.5-2 amps while still only using single output transistors. Maybe the MJ15003 would be better for this?
Thanks,
Greg.
gregjpeters
I seem to remember reading that the 21193/21194 were one of
the first of the enhanced beta types and performed better into 4 ohm loads than previous types. To quote from a Silicon Chip
Class A project in 1998 : "We used them because they are achknowled to be among the very best transistors for linearity
made by any manufacturer in the world. And by using them at much lower current than their design currents and voltages
we get even better linearity."
The 1302/3281 etc are even better again.
SandyK
I seem to remember reading that the 21193/21194 were one of
the first of the enhanced beta types and performed better into 4 ohm loads than previous types. To quote from a Silicon Chip
Class A project in 1998 : "We used them because they are achknowled to be among the very best transistors for linearity
made by any manufacturer in the world. And by using them at much lower current than their design currents and voltages
we get even better linearity."
The 1302/3281 etc are even better again.
SandyK
gregjpeters said:
I doubt that the MJ15003's hfe linearity would be better than that of the MJL21194. Also (according to the ON semi datasheet), the MJ15003 has a nominal fT of 2MHz, half that of the MJL21194 and a much bigger collector-base (Cob) capacitance of 1000pF.
I'd go for the MJL21194.
Also, in case you might consider using a 30MHz fT part such as the 1302, just be wary that if your JLH amp is dependant on the limited bandwidth of the output stage for stability, or is not sufficiently well layed out, such parts could make it an oscillator.
Greg, you have use MJL21194 for the JLH class A design did you ? Do you experience oscillation as well ? or humming ?
How's the sound ? did you manage to bias for 2 Amp or more ? And hows the result.
Well I try using recommended MJ15003 double and bias 2Amp.
The bass is as detail as the mid and high. But I intrigue about MJL21194, as it is reported better linearity.
Maybe Greg could give us some clue here...
How's the sound ? did you manage to bias for 2 Amp or more ? And hows the result.
Well I try using recommended MJ15003 double and bias 2Amp.
The bass is as detail as the mid and high. But I intrigue about MJL21194, as it is reported better linearity.
Maybe Greg could give us some clue here...
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