Hmm, i think mjl21193/4 is already best choice, cheaper transistors
have smaller SOA, means you need more of them !
At these high voltages there are not many alternatives.
And don't forget, costs for electronic devices are very small compared
to heatsink, transformer and psu-caps !
If cost is a problem, try less power and you will need less transistors,
smaller caps,smaller heatsink and smaller/cheaper caps !
With a 100watts into 8 ohm you can live with a single pair of the mjl's.
You could use the mj21193/4 in TO3-case, it's might be slightly cheaper.
Mike
have smaller SOA, means you need more of them !
At these high voltages there are not many alternatives.
And don't forget, costs for electronic devices are very small compared
to heatsink, transformer and psu-caps !
If cost is a problem, try less power and you will need less transistors,
smaller caps,smaller heatsink and smaller/cheaper caps !
With a 100watts into 8 ohm you can live with a single pair of the mjl's.
You could use the mj21193/4 in TO3-case, it's might be slightly cheaper.
Mike
djk said:
It is hard to compare SOA's charts, so I was wandering if the SOA is better on the MJL21193/94.
SOA on the Sanken is specified at DC and 10ms, on the MJL21193/94 at 1sec...
But if I compare the Sanken with the SOA charts of the MJL21195/96 ,which are also specified at 10ms, it seems that the SOA at 10ms is better on the Sanken.
Or am I wrong on this ?
Jan
Hi,
correct me if I am wrong but I believe that SOA are for one off events. So 10ms must not repeat within a sensible period say a couple of seconds. This would not suit music peaks which are liable to repeat frequently. Similarly even the 100ms and 1s (but now the repeat time is extended to many seconds) figures must not repeat too close together. Safer to use the DC figures if the manufacturer quotes them.
regards Andrew T.
correct me if I am wrong but I believe that SOA are for one off events. So 10ms must not repeat within a sensible period say a couple of seconds. This would not suit music peaks which are liable to repeat frequently. Similarly even the 100ms and 1s (but now the repeat time is extended to many seconds) figures must not repeat too close together. Safer to use the DC figures if the manufacturer quotes them.
regards Andrew T.
Extrapolating the graphs, I think MJL DC SOA is almost the same as Sanken's SOA up to 100V. Above 100V MJL show better SOA
But Sanken's feature much less charge storage [Ft is 10 times higher] and higher current gain at the same time [sometimes twice the gain of MJLs]
I think Sanken's look more like linear amplifier transistors while MJLs look more like high voltage low gain switching transistors
PD: This handful of Sankens are all fakes, be careful...
But Sanken's feature much less charge storage [Ft is 10 times higher] and higher current gain at the same time [sometimes twice the gain of MJLs]
I think Sanken's look more like linear amplifier transistors while MJLs look more like high voltage low gain switching transistors
PD: This handful of Sankens are all fakes, be careful...
Attachments
2SA1295 / 2SC3264 US$8.50 each www.ampslab.com
They claim: Sanken - Guaranteed Originals at AmpsLab
The MJL21193/21194 cost about the same, but I like the MJL3281A/1302A pair more.
They claim: Sanken - Guaranteed Originals at AmpsLab
The MJL21193/21194 cost about the same, but I like the MJL3281A/1302A pair more.
Well, not all Sankens are fakes, those of the picture are all genuine devices, altough they come from four different production batches and require manual matching. Spanish component dealers are quite incompetent
Also I wouldn't be so concerned about SOA if I was you. Two pairs of these have survived flawlessly a test with 85V sagging [75V] rails driving a 4 ohm 15" horn loaded driver [reactive load] with music LF signals at full output swing [And I think two pairs of MJL2119x would also survive]
Also I wouldn't be so concerned about SOA if I was you. Two pairs of these have survived flawlessly a test with 85V sagging [75V] rails driving a 4 ohm 15" horn loaded driver [reactive load] with music LF signals at full output swing [And I think two pairs of MJL2119x would also survive]
Attachments
I WOULD GET MJL'S BUT I CAN'T FIND THEM, I INITIALY ORDERD SOME,FROM A ONLINE MAGAZINE(THE ONLY PLACE I FOUND THEM,THE ORIGINAL),HERE IN ROMANIA,BUT THEY SAID THEY DON'T HAVE THEM ANY MORE,AND I DON'T KNOW IF THEY ARE EVER GOING TO BRING THEM,ONLY CHEAP COPYES.....
AT THE SAME STORE, (THEY SAID IT'S THE ORIGINALS THING OR MANY BACK..) I FOUND THE OTHER TRANSISTORS,I HAVE MADE THE ORDER,AND NEW I AM WAITING FOR THE ORDER TO ARIVE...
HERE IS THE AMP,BUT I HAVE MADE SOME MODIFICATIONS TO IT...
AT THE SAME STORE, (THEY SAID IT'S THE ORIGINALS THING OR MANY BACK..) I FOUND THE OTHER TRANSISTORS,I HAVE MADE THE ORDER,AND NEW I AM WAITING FOR THE ORDER TO ARIVE...
HERE IS THE AMP,BUT I HAVE MADE SOME MODIFICATIONS TO IT...
Attachments
MJLs may be available from www.arrow.com. However there may be minimum quantities and and a backorder time.
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