that is an imposible thing to do. so no 🙂 play the amp With all 5 ch to max temperature and then use an hour to screw it apart to adjust bias? that's just not posible.
That works fine for class A amps🙂 but A/B amps is a different story 🙂
also. the hour i would use to tare it down, it would also cool Down.
also. the hour i would use to tare it down, it would also cool Down.
I prefer to adjust my bias with the amp just idling for a while with all it's covers in place. If the bias circuit is working properly it shouldn't change much at all with changes in temperature. I also try to lay out my boards with the bias pot accessible with the amp assembled, just quickly pop the top cover off and adjust.
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thank you 🙂 thats what i did too 🙂 wel. i dont have the pot accessible doh. the layout did not allow it. but i can Reach the offset pot🙂
I allmost can't wait untill the diodes get here. iIdid get a taste of it's sound. One channel played for about an hour a couple of days ago. and the sound was damn good.I have never heard those testspeakers play that good. And with a good and deep bass🙂
yes it is 🙂 it will be a dream in the home theater. if i ever get it there 🙂 it has a backbraking weitght to it 😀
Now it's up and running. All 5ch adjusted and looks to be stable. Around 68mA bias and offset is 0.0-0.2mV. also played music on all 5 and rechecked bias. turned it off for cooling and back on again to recheck bias. all good so far. it starts at around 32mV when cold. And setles back down at 30mV after a short while.
Congratulations, good job.
I run mine at somewhat higher bias of 75mA, use 0.18ohm emitter resistors and +/-63.5V. With 5 channels your transformer must be huge. I guess at least 1.5kVA if 5 channels were to sing.
cheers,
I run mine at somewhat higher bias of 75mA, use 0.18ohm emitter resistors and +/-63.5V. With 5 channels your transformer must be huge. I guess at least 1.5kVA if 5 channels were to sing.
cheers,
Tnx. the transformer is only 1000VA. It's a transformer i had in my bin. I will get another transformer in the future. But no more then 1.2KVA. It's a HT amp after all 🙂
I want to build a dual mono PSU and I can't decide on the filtering capacitors. In the build guide it says that you need 40000uf per rail. Is this for both channels or for just one channel?