Hi guys,
I am making a 400W @4ohms amp based closely on the blameless design topology and I have used 6output pairs of 2Sc5200&1943 to be safe , for drivers I have the option of 4893/1843 or MJE15032/31 , which one should I go for ?.
As per my calculations which may be incorrect , to drive a load of 400W at 4ohms I will be needing 10A of out put current and considering lowest Hfe of 15 , I would need 110mA current per device or total 660mA. So would the 4793/1843 drivers be enough or should I move over Mje15032?
I am making a 400W @4ohms amp based closely on the blameless design topology and I have used 6output pairs of 2Sc5200&1943 to be safe , for drivers I have the option of 4893/1843 or MJE15032/31 , which one should I go for ?.
As per my calculations which may be incorrect , to drive a load of 400W at 4ohms I will be needing 10A of out put current and considering lowest Hfe of 15 , I would need 110mA current per device or total 660mA. So would the 4793/1843 drivers be enough or should I move over Mje15032?
The typical Hfe of c5200/a1943 is 120 for O type with min 80. 4 ohms load is min 3 ohms, to consider 2 ohms for bass reflex phase shift. This gives 20A/120, you need 166ma rms or 230ma peak, total driver current. One pair or ten pair outputs, the story is the same.
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Hi,
I would use MJE15032/33 to stay on the safe side. The 4793/1837 has very limited SOA at high voltage.
Sajti
I would use MJE15032/33 to stay on the safe side. The 4793/1837 has very limited SOA at high voltage.
Sajti
Kokoriant, Sajti , Russel , thanks for the pointers. I have completed assembling my amp with the suggested MJE15032/33 drivers and it's works beautifully... Puts out close to 550W on 4ohms..
I agree. Or you can parallel the 4793/1837 or you can drive 3 sets of transistor output with 4793/1837 then parallel the driver and the outputs. Using 4793/1837 can give high slew rate because they have much less Cob.
Generally good idea. The only problem, that 4793/1837 is not manufactured since years. There are many fakes around.
Good, and fast drivers are dead 🙁 Only the 4883/1859 pair, which is still standing...
Sajti