anatech said:
Hi Chris, phew, difficult question !
None of the devices seem absolute perfect, it's sure that the MJL0281 outperforms the MJL3281, they have similar sound, but the newer ones have more details, and the MJL3281 sounds a bit agressive.
The slower MJL21196 have a very musical sound but lack performance with trebles. The Toshiba sc5200 showed the best overall performance, but don't reach the MJL0281 regarding resolution and clarity.
I think i will stick with the MJL0281...
Interesting, the sound of the MJL21196 gives the feeling to have doubled up the bass, might be caused by 2nd harmonics ?
Mike
Hi Mike,
Interesting observations for sure.
You didn't happen to run these amps through RMAA to compare the different ouputs did you? Also, did you match the outputs and drivers? What I am wondering is how much device matching may have to do with the sound quality.
The first unit (ver 5.3) is almost ready for playing with. I am waiting for driver transistors. I may buy a bunch of polystyrene caps to relace the ceramics. My past experience leads me solidly towards these cap types. I can only find them in 50V. My input cap is 1 uF, 4u7 and 10uF both non-stock and expensive as sin!!
A shot of the board
-Chris
Interesting observations for sure.
You didn't happen to run these amps through RMAA to compare the different ouputs did you? Also, did you match the outputs and drivers? What I am wondering is how much device matching may have to do with the sound quality.
The first unit (ver 5.3) is almost ready for playing with. I am waiting for driver transistors. I may buy a bunch of polystyrene caps to relace the ceramics. My past experience leads me solidly towards these cap types. I can only find them in 50V. My input cap is 1 uF, 4u7 and 10uF both non-stock and expensive as sin!!
A shot of the board
-Chris
Attachments
Hi Chris,
Thanks for the measurements! I see your board is coming along nicely!
Hi MikeB,
Appreciate very much the input re sound of the 21195/6! I might try building two amp pairs then, using the slower outputs to drive the midranges and the higher-speed MJL3281 pair for the HF...
After I work off this jet-lag I'm gona start stuffing these boards!
Cheers,
Clem
Thanks for the measurements! I see your board is coming along nicely!
Hi MikeB,
Appreciate very much the input re sound of the 21195/6! I might try building two amp pairs then, using the slower outputs to drive the midranges and the higher-speed MJL3281 pair for the HF...
After I work off this jet-lag I'm gona start stuffing these boards!
Cheers,
Clem
Hi Clem,
I expect the drivers to arrive shortly. My other caps have been back ordered for about 3 weeks yet. Some days you just can't win.
I remember about 10 years ago, getting the polycarbonate and polystyrene types was easy (and local). Mouser is a bit of a pain to deal with and Digi-Key (excellent shipping!) do not stock much in caps really.
How do you like the neat low inductive, vertical resistors I found ?
-Chris
Edit: Good to see you back Clem, all rested now?
I expect the drivers to arrive shortly. My other caps have been back ordered for about 3 weeks yet. Some days you just can't win.
I remember about 10 years ago, getting the polycarbonate and polystyrene types was easy (and local). Mouser is a bit of a pain to deal with and Digi-Key (excellent shipping!) do not stock much in caps really.
How do you like the neat low inductive, vertical resistors I found ?
-Chris
Edit: Good to see you back Clem, all rested now?
Faked Motorola????
Are these transistors a fake or originals
I bought these from China: MJ15003/4 for $ 0.80
Case: steel (shape as originals), logo: "M" as indicating Motorola.
Inside: cu-heat sink and die that looks like exactly as in the pictures here (Picture of original genuine parts: the To-3 on the right):
http://sound.westhost.com/fake/counterfeit-p1.htm#15003
Die size was measured to be 5 x 5 mm.
Only difference was that the MJ15003/4 that Iv bought had a thicker connector wire to Base.
Measuring B-E capacitance didnt show any large differences compared to original samples from the On Semiconductor. Text is oriented also as originals, but the text could be washed away by the use of acetone (it was also the case to the samples?). Now, the date-code on these transistors shows: 0418 indicating these where produced in 2004, but with the Motorola-logo????? Could this be fakes?
Final tests would be to measure SOA, or what do you think? How do I handle these parts?
Regards
Are these transistors a fake or originals
I bought these from China: MJ15003/4 for $ 0.80
Case: steel (shape as originals), logo: "M" as indicating Motorola.
Inside: cu-heat sink and die that looks like exactly as in the pictures here (Picture of original genuine parts: the To-3 on the right):
http://sound.westhost.com/fake/counterfeit-p1.htm#15003
Die size was measured to be 5 x 5 mm.
Only difference was that the MJ15003/4 that Iv bought had a thicker connector wire to Base.
Measuring B-E capacitance didnt show any large differences compared to original samples from the On Semiconductor. Text is oriented also as originals, but the text could be washed away by the use of acetone (it was also the case to the samples?). Now, the date-code on these transistors shows: 0418 indicating these where produced in 2004, but with the Motorola-logo????? Could this be fakes?
Final tests would be to measure SOA, or what do you think? How do I handle these parts?
Regards
Dear MikeB
If I had knew of transistor-fakes I hadnt bought from China but I didnt knew. Thats why, I dont support a fake-production MikeB.
I was searching for a good price for another type of transistor, not Motorola brand (IXYS IGBTs).
When finding them at a supplier in Hong Kong I also asked for these Motorola MJ15003/4 and they had them and they offered them to a good price due to my big order for all the other parts.
Anyway, this is what was inside those Motorola MJ15003/4 (the top cap was not easily removable) :
You could make your own judgement but to me it looks like an original, if not, its a damn good fake isnt it ?
Regards
If I had knew of transistor-fakes I hadnt bought from China but I didnt knew. Thats why, I dont support a fake-production MikeB.
I was searching for a good price for another type of transistor, not Motorola brand (IXYS IGBTs).
When finding them at a supplier in Hong Kong I also asked for these Motorola MJ15003/4 and they had them and they offered them to a good price due to my big order for all the other parts.
Anyway, this is what was inside those Motorola MJ15003/4 (the top cap was not easily removable) :
You could make your own judgement but to me it looks like an original, if not, its a damn good fake isnt it ?
Regards
Attachments
Manufacturing undoubtly looks like genuine On-Semi, however, be aware that they may be rebranded transistors from other On-Semi model. Rebranding transistors into higher power ones is a very common practice requiring very little knowledge and resources, unlike fake manufacturing. That may also explain why part number shows "Morotola" and dissolves into acetone so easily.
Rebranding higher technology parts like IGBTs and MOSFETs is rather easy too, so be careful.
Rebranding higher technology parts like IGBTs and MOSFETs is rather easy too, so be careful.
Refering to your first photo, the 2 on the top left look suspicious, missing the "JAPAN" is often a bad sign...
The 2 on the lower left look exactly like Toshibas actual manufacturing, and the right ones look like the older cases.
My guess is, that only the 2 on the top left are fakes, but only a guess.
Mike
The 2 on the lower left look exactly like Toshibas actual manufacturing, and the right ones look like the older cases.
My guess is, that only the 2 on the top left are fakes, but only a guess.
Mike
One thing I've noticed,the green-colored PNP ones generally tend to be The Genuine Product.
Alot of the time if you get a replacment for the green PNP ones,that isn't green,it's a fake. (though,it seems not 100% of the time.)
Did the original manufacturers stop using the green cases?
Some Genuine Original PNP replacments I got were in black,instead of green,but they looked original,and they seem to be holding up just fine.
Maybe that's another detail we can use to find fakes?
Alot of the time if you get a replacment for the green PNP ones,that isn't green,it's a fake. (though,it seems not 100% of the time.)
Did the original manufacturers stop using the green cases?
Some Genuine Original PNP replacments I got were in black,instead of green,but they looked original,and they seem to be holding up just fine.
Maybe that's another detail we can use to find fakes?
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