Now...I replaced ne5532 with tl072, and you can see wath happen on dummy load 4R. ...I tried at +-48 volt and also at +-85 volts with same results. Where is the problem?
https://youtu.be/gpc9TaKNw58
Hi folks , I want to upgrade my B500 channels with more output devices , long story short I have some spare 2sa/2sc5200/1943 transistors and I would like to double the transistor count on each board but surely the MJE15032/33 drivers can't handle up to 8 devices each so can you please suggest what I would need to change in the driver transistors to do that.?
I will add a part of schematic I found in this thread maybe someone has the full schematic and or advice.
thank you
I will add a part of schematic I found in this thread maybe someone has the full schematic and or advice.
thank you
Attachments
in that case rather use triple emiter follower,using first 2SA1943 2sc5200 and their emiter resistors...
but do I need to change the driver stage at all? maybe I can just add the extra 8 transistors (4 on each side) because for a decent output load of say 10 amps the 2sa1943 has a hFE of about 160, when I divide the amps with the hFE I get about +-70mA for base current but since the output transistors are paralleled the base current for each transistor is even smaller so the total base current is not that big why would I need a 2sa1943 to drive 8 2sa1943 devices?
if the mje15032/33 collector current is about 8 amps max.
that would be at max an average of 1amp for each output transistor base current but do they really ever get to that margin?
if the mje15032/33 collector current is about 8 amps max.
that would be at max an average of 1amp for each output transistor base current but do they really ever get to that margin?
It is clear you cannot redesign this amplifier.
Therefore don't try to redesign it.
Leave that to someone who does not need to ask these SOA questions.
Therefore don't try to redesign it.
Leave that to someone who does not need to ask these SOA questions.
With all due respect I will redesign it simply because I have the parts and asking questions is a way of learning, just as some said that better not build an smps yet I built one and it works, sure not without mistakes in the process.
I needed to refresh my knowledge about this, now I did some simple math in the other thread and I do think the drivers are actually capable of 8 devices per side operation. It would be very nice if you would have also stated your opinion other than that I shouldn't do this.
Just in case I have a scope so if there will be some problems with gain or distortion I will hopefully be able to see them
I needed to refresh my knowledge about this, now I did some simple math in the other thread and I do think the drivers are actually capable of 8 devices per side operation. It would be very nice if you would have also stated your opinion other than that I shouldn't do this.
Just in case I have a scope so if there will be some problems with gain or distortion I will hopefully be able to see them
imho. the 5200/1943 are high hfe devices that adding more pairs is NBD...
this is a very good source of correct information...http://www.cieri.net/Documenti/Altr...eband-Low Feedback Design (AN1308 - 1992).pdf
this is a very good source of correct information...http://www.cieri.net/Documenti/Altr...eband-Low Feedback Design (AN1308 - 1992).pdf
oh by the way what is the bias current in the b500 in its original form? I see it is set by the voltage divider at mje340 base which then sets bias for the drivers which in turn bias the output devices.
I am just curious about the average mA that goes through an output transistor with the (680/330) resistive divider at mje340?
I am just curious about the average mA that goes through an output transistor with the (680/330) resistive divider at mje340?
Hi, everyone...can you tell me which are better replacement for mje15032/mje15033??
For b500 can I use mje15034/mje15035 pair at driver stage to drive mjl3281/mjl1302 (5pair) ?? Or mje15030/mje15031 will be better replacement??
For b500 can I use mje15034/mje15035 pair at driver stage to drive mjl3281/mjl1302 (5pair) ?? Or mje15030/mje15031 will be better replacement??
Thanks for your suggestion .But i don't find it.No stocks in mouser.in.only mje15034/mje15035 available.
