Hi, i have on JL 300/2 4x irf540 and 4x unknow mosfet, somepeople know this mosfet? I don't found info about this device...
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Ah ok, thanks, but don't is strange? This ampli have 4x IRF540 and 4x this unknow mos..
I did this work for more than 30 years. Nothing really surprises me anymore. They could have been installed by anyone. The solder doesn't look like flow soldering.
Ok, maybe, i don't know..
Maybe you know voltage bias adjust on ceramic resistor for this amplifier?
Maybe you know voltage bias adjust on ceramic resistor for this amplifier?
I don't know what the factory recommends. I've found a lot at 4mv which I believe is excessive. I prefer setting them as in the demo below:
http://www.bcae1.com/temp/ausettingbias.swf
http://www.bcae1.com/temp/ausettingbias.swf
I could not find that part number but it could be a fast schottky rectifier similar to this. https://static6.arrow.com/aropdfcon...21ff47d54a448a832ed42182/sdp20s30_rev.1.4.pdf
It might be sitting near / connected to the coil. Do you have a schematic?
What are you powering the amp with?
How high is the DC voltage feeding the amp after 5 minutes?
If you lower the 12v power supply voltage, that waveform will probably look more like you're expecting.
How high is the DC voltage feeding the amp after 5 minutes?
If you lower the 12v power supply voltage, that waveform will probably look more like you're expecting.
I powering with 40A switching power supply, 12.6V.
What is "dc voltage feeding the amp"? You mean rail voltage?
Yes, i have tryed also with 14.0V, but is the same. I have this square wave unstable also on sg3525 output..
If you play music at a fairly high level, does the amp do this?
Does it produce music normally when the instability starts?
Does it produce music normally when the instability starts?
Yes, i have tryed also with 14.0V, but is the same. I have this square wave unstable also on sg3525 output..
i have played low volume music, i must try with high volume.
i don't know, let you know.
i have misured also square wave on SG3525 output, is clean, but when instability start (change frequency), also this square wave is unstable. can be sg3525 broken?
I doubt that the is a defective 3525.
We need to check quite a few more things. For now, test at high power.
We need to check quite a few more things. For now, test at high power.