First hello to all.
I sorry if there are another posts with the same problems with my thread.
I have built Rod Elliott P3A amp ( seem it very popular 😀 ), the temp output transistors is NJW0281 and NJW0302. I consider to buy "bigger" (power ratings) and better ones. But I don't know what should I choose in the following list:
+ MJL3281/1302
+ NJW3281/1302 (any different from MJL or MJW type except case styles?)
+ NJL3281/1302
+ MJL4281/4302
+ MJL21193/21194 (also vs NJW and MJ types?)
+ MJ15003/15004
+ MJ15022/15023 (15024/15025???)
I am not have enough money to buy all those to test and find out the best for lowest THD and flat freq response 😕 . Seem be the datasheets don't tell much.
I sorry if there are another posts with the same problems with my thread.
I have built Rod Elliott P3A amp ( seem it very popular 😀 ), the temp output transistors is NJW0281 and NJW0302. I consider to buy "bigger" (power ratings) and better ones. But I don't know what should I choose in the following list:
+ MJL3281/1302
+ NJW3281/1302 (any different from MJL or MJW type except case styles?)
+ NJL3281/1302
+ MJL4281/4302
+ MJL21193/21194 (also vs NJW and MJ types?)
+ MJ15003/15004
+ MJ15022/15023 (15024/15025???)
I am not have enough money to buy all those to test and find out the best for lowest THD and flat freq response 😕 . Seem be the datasheets don't tell much.
Last edited by a moderator:
From a practical point of view those will all sound the same so save time and money.
The *minute* differences may be picked by a well equipped Lab test but not by the kind of test you can probably make: mount one pair ... listen ..... try another ... listen ... ad nauseam.
In the 5 or 10 minutes (at least) taken by transistr swapping your ear will lose memory needed for accurate comparison.
If anything, you´d need to have 8 amplifiers ready made , each with a different pair, and quickly switch back and forth, and *then* you might pick a small difference.
A simulator might tell you one has 0.03578% distortion and another 0.04625% so in theory the first one is "better" or one reaches 78kHz while another only does 72 kHz ... not an audible difference .
IF you wish, simulate all them and choose.
It will definitely be cheaper 😉
The *minute* differences may be picked by a well equipped Lab test but not by the kind of test you can probably make: mount one pair ... listen ..... try another ... listen ... ad nauseam.
In the 5 or 10 minutes (at least) taken by transistr swapping your ear will lose memory needed for accurate comparison.
If anything, you´d need to have 8 amplifiers ready made , each with a different pair, and quickly switch back and forth, and *then* you might pick a small difference.
A simulator might tell you one has 0.03578% distortion and another 0.04625% so in theory the first one is "better" or one reaches 78kHz while another only does 72 kHz ... not an audible difference .
IF you wish, simulate all them and choose.
It will definitely be cheaper 😉
I think is a problem. I have design my own boards and it work very well, no oscillation... I can re-draw for other output transistors package.
Diodes inside NJL can put use as a part of automatic bias controller.
I can say that I like TO-3 case much more than plastic case because of they thermal resistant. The boards can be smaller and can be mounted easier but more reliable than use plastic case. But unfortunately, they more expensive and MJ-150xxx seem don't have as good as characteristics as plastic case.
Well, countryman.
I often use Sanken LAPT in my design, AKA 2SC3519A, 2SC2922... but a friend who told me MJL3281A/MJL1302A is the best for overall. They not expensive like big Sanken.
In other hands, i also don't care about THD of output transistor, everything i want just is sounding.
I often use Sanken LAPT in my design, AKA 2SC3519A, 2SC2922... but a friend who told me MJL3281A/MJL1302A is the best for overall. They not expensive like big Sanken.
In other hands, i also don't care about THD of output transistor, everything i want just is sounding.
Thanks bro.
I also like MJL3281/1302 because they gain are only less matched than NJL3281/1302.
I care about linearity, THD and flat freq response. I don't care so much if sound is suitable for me. I only want to re-create the sound as close as the origin live sound as I can 😀 .
Your care look like some audio magazine say: try to create original sound. Forget if i wrong, that never happen! Due the sound as you hear is the signal after A LOT OF equipment, it means a lot of circuits. As you know, the sound through any circuit that will be changed, even that circuit is a resistor!
I was made few amp, each of them creates a different color. I never try to make an amp, that have what your said: original sound!
Certainly not like the origin!
But I want the one make least coloration to the sound.
Well, your care as many others. How do you know what is the color of sound?! Your reference?!
That is a general thing, but why do you don't care about your input stage?! The sounding of an amp, most comes from LTP/VAS if same as kind of output transistor of course.
However, ON Semi tranny be evaluated as your need, at least color.
That is a general thing, but why do you don't care about your input stage?! The sounding of an amp, most comes from LTP/VAS if same as kind of output transistor of course.
However, ON Semi tranny be evaluated as your need, at least color.
Of course I know what is called "color", they are "kind" or "type" of harmonics distortions which are the main reason affect the sound.
I don't care about LTP and VAS, they are fixed. Only output stages are flexible.
Provided the correct "type" of transistor is selected to suit the duty then the transistor no matter which manufacturer makes it will not affect the "sound" nor affect the performance of the amplifier.
Most of the performance differences are due to selecting the wrong components for the duty intended. This applies to resistors and capacitors and inductors and transistors and diodes.
Select the correct type and every version of that amplifier will perform near enough identically.
Most of the performance differences are due to selecting the wrong components for the duty intended. This applies to resistors and capacitors and inductors and transistors and diodes.
Select the correct type and every version of that amplifier will perform near enough identically.
Very true Andrew!
My P3A build has plain vanilla 2SC1953/2SA5200 outputs and sounds great every day.
My P3A build has plain vanilla 2SC1953/2SA5200 outputs and sounds great every day.
If you check the history of P3a, you find it began with very basic parts many years ago and doesn't sound greatly different even now with modern high Ft parts. My version using much slower MJL21193/4 (also recommended) sounds better to me than when I had it fitted with MJL4281/4302 ( high voltage versions of MJL3281/1302).
As hinted at, the P3a amplifier sound is coloured and that's actually what makes it sound good to many DIY audio enthusiasts. To redesign it, making it a clean and low distortion model would be a waste of parts though. There are better designs for pure, ultra low distortion audio but they tend to be larger, more complex and expensive to build such that they also sound good.
As hinted at, the P3a amplifier sound is coloured and that's actually what makes it sound good to many DIY audio enthusiasts. To redesign it, making it a clean and low distortion model would be a waste of parts though. There are better designs for pure, ultra low distortion audio but they tend to be larger, more complex and expensive to build such that they also sound good.
Last edited:
Bad boy Ian ...pepper in your mouth😀😀😀😀😀
Please edit your post and remove "colored" from it, very bad choice of word ...you should describe the P3A as an amplifier with different "packet " of harmonics....😛😛😛
Kindest regards
Sakis
Please edit your post and remove "colored" from it, very bad choice of word ...you should describe the P3A as an amplifier with different "packet " of harmonics....😛😛😛
Kindest regards
Sakis
Hi Sakis. Ah-ah-achoooo! 😱 heh,heh - I like it a lot and I prefer colour to B+W TV too - don't we all?
Seriously though, a lot of guys don't understand what distortion really sounds like in various mixes and what psychological effects low order harmonics can have in small amounts. They probably just see an ugly word and assume it always means bad, like disease.
However, the harmonic distortion I'm referring to isn't just a random spray of all harmonics but a carefully trimmed order that for most tastes, would decline from 2nd to 5th harmonic of fundamental tones right up through the midrange, where we focus on information about the environmental sounds we hear, such as their position and movement. That would be an unlikely as a result of a poor design or part swapping.
Actually, I enjoy making and hearing even more details in the sound than were recorded 🙂
Seriously though, a lot of guys don't understand what distortion really sounds like in various mixes and what psychological effects low order harmonics can have in small amounts. They probably just see an ugly word and assume it always means bad, like disease.
However, the harmonic distortion I'm referring to isn't just a random spray of all harmonics but a carefully trimmed order that for most tastes, would decline from 2nd to 5th harmonic of fundamental tones right up through the midrange, where we focus on information about the environmental sounds we hear, such as their position and movement. That would be an unlikely as a result of a poor design or part swapping.
Actually, I enjoy making and hearing even more details in the sound than were recorded 🙂
What is the reason for "bigger" power rating? Smaller power rating usually sounds better due to smaller capacitance...
I'm not so sure but it seems that the bigger plastic package in general tends to be better than the smaller one?? So choose MJL instead of MJW if possible, if not, consider they are similar.
For "bigger" power, MJL21193 and MJL3281 seems to be a better options. If THD is a priority, I guess MJL3281 has a better chance. The real quality will depend on matching and also on what transistor you use in the VAS.
Correct Ian I Agree ...
Though the list of semis of the OP is very wide and includes from very fast till very slow transistors Eventually this will have some impact on the sound of the amplifier .
Also wiring/pcb between plastics and cans will be far more different resulting also some small impact after all .
Finally i see no descussion from the OP about Vas drivers and compensation so obviously OP havent done his homework .....
Mixmatching is the key as described in the thread ...It took me from 2006 till now to measure different variations , evaluate , and come up what i think is the best ...
2SA1302 -3281 rocks but as we many times said unobtainable for common people .
By the way one thing i haven't done is work with MOT200 2922 series but i think is an overkill to use such an output for 50W amplifier .....May be i will in the feature ...Overkill doesn't bother me as long as it sounds better than 1302-3281.
Kindest regards
Sakis
Though the list of semis of the OP is very wide and includes from very fast till very slow transistors Eventually this will have some impact on the sound of the amplifier .
Also wiring/pcb between plastics and cans will be far more different resulting also some small impact after all .
Finally i see no descussion from the OP about Vas drivers and compensation so obviously OP havent done his homework .....
Mixmatching is the key as described in the thread ...It took me from 2006 till now to measure different variations , evaluate , and come up what i think is the best ...
2SA1302 -3281 rocks but as we many times said unobtainable for common people .
By the way one thing i haven't done is work with MOT200 2922 series but i think is an overkill to use such an output for 50W amplifier .....May be i will in the feature ...Overkill doesn't bother me as long as it sounds better than 1302-3281.
Kindest regards
Sakis
Last edited:
It would be nice to show some actual P3A distortion graphs. To me, words sound just like ...words. Anybody tried?
Agree!
All I want is the performance. I don't care about what will they sound. With me, low distortion, stablity and flat response are the most important thing 😀 . I also love the simple very much!
- Status
- Not open for further replies.