hi
i have replaced TIP35/36C blow out put stage trasistors from Focal amp and replaced with 2SC5200 pairs.
Now there is a REFERENCE POINT and BIAS CHECK point. The voltage across all four channels is 2mV to 80 mv.
VCE= 30.6 volt for all
VBE= 0.35V to 0.55 Volt ?
Any guidance how to adjust bias before i blow them out again.
i have replaced TIP35/36C blow out put stage trasistors from Focal amp and replaced with 2SC5200 pairs.
Now there is a REFERENCE POINT and BIAS CHECK point. The voltage across all four channels is 2mV to 80 mv.
VCE= 30.6 volt for all
VBE= 0.35V to 0.55 Volt ?
Any guidance how to adjust bias before i blow them out again.
hi
i have replaced TIP35/36C blow out put stage trasistors from Focal amp and replaced with 2SC5200 pairs.
Now there is a REFERENCE POINT and BIAS CHECK point. The voltage across all four channels is 2mV to 80 mv.
VCE= 30.6 volt for all
VBE= 0.35V to 0.55 Volt ?
Any guidance how to adjust bias before i blow them out again.
TIP 35 is an NPN whereas TIP36 is PNP inferring a complementary pair. 2SC5200 is NPN, It would suggest to me that you need a PNP to match the replacement of the TIP36.The correct complement for the 2SC5200 is a 2SA1943
Cheers / Chris
Last edited:
just forgot to mention though in my earlier post. yes indeed it 2SA5200 was matched with 2SA1943, and tried to match within 5% of VBe, not sure of hFE though.
Biasing ? VBE ? HELP?
Data sheet here: http://www.fairchildsemi.com/ds/FJ/FJL4315.pdf
Cheers / Chris
No. Actually its second replacement, the yesterday replacement were all well before i put a bridged load on it.
A bridged load needs to be twice the none bridged load.
nigel my question is not about the load in bridge load its about biasing after changing the out put transistors.
I dont think anything else is destroyed as i powered up the amp through a series bulb resistor, it has turned on and with small signal input all the channels are working fine without much current draw to indicate a shortage or overheating,
But how do i check whats the ideal bias current ? at what value should i adjust the bias pots. ?
I dont think anything else is destroyed as i powered up the amp through a series bulb resistor, it has turned on and with small signal input all the channels are working fine without much current draw to indicate a shortage or overheating,
But how do i check whats the ideal bias current ? at what value should i adjust the bias pots. ?
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