Just got delivery of a MA12070 amp by BRZHiFi. Seems quite well made and powers on ok but I havent listen to it yet.
Uses TL072 op amps which look easy to change as do various caps, volume control etc.
Output filter looks a bit odd though, 15uh in each +/- leg with 1nf across +/- ( not connected to 0V). Ive read the application
note on output filters and its not anything like the recommendations. There seems to be room enough to add the recommended
filters but I'll see how it sounds first.
Uses TL072 op amps which look easy to change as do various caps, volume control etc.
Output filter looks a bit odd though, 15uh in each +/- leg with 1nf across +/- ( not connected to 0V). Ive read the application
note on output filters and its not anything like the recommendations. There seems to be room enough to add the recommended
filters but I'll see how it sounds first.
Well you need to test your Chipstar amp and start a Chipstar hype, so everybody orders MA12070 hoping to receive the magic Chipstar and JeanPaul decides to design a pcb for the Chipstar 🙂
Why would I? The layout already looks AOK but bad numbers that can not be solved. Not much PCBs from me anymore with todays reality/economy. I am going full ChiFi 😀
BTW: TNT, you wrote " 18 ohm in series with the horn" which is among the worst possible actions with either loudpeakers and (class D) amplifiers. Why do you do that?
BTW: TNT, you wrote " 18 ohm in series with the horn" which is among the worst possible actions with either loudpeakers and (class D) amplifiers. Why do you do that?
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A well designed PCB for the MA5332 which supposedly is the newer cousin of MA12070. Is it just as good? I don't know but it is 200W which everyone seems to want and and it is way noisier than its older cousins. I think it is not the newer version of MA12070 but of other IRS series chips by Infineon.
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d4627a0b0c7b017a3f402ad026a2
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d4627a0b0c7b017a3f402ad026a2
Well, every amp I have tested so far I can hear noise from the tweeters if I dont. And also for gain structure.
And distorsion reduction? 🙂
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A designer.
As said: a wrong laymen technique leading to nothing but added issues. You don't reduce gain at the outputs. Also you don't reduce gain the right way by adding series resistors to loudspeakers and it certainly will not reduce distortion 🙂 Damping factor will be miserable, efficiency will be sub normal, filters of class D won't work correctly etc. etc. Have it your way but you are not on the right rack, sorry. It is based on empirical results and assumptions. One can solve issues by the root which is most effective and has less side effects.
Strongpoint of MA12070 is the very low noise.....
As said: a wrong laymen technique leading to nothing but added issues. You don't reduce gain at the outputs. Also you don't reduce gain the right way by adding series resistors to loudspeakers and it certainly will not reduce distortion 🙂 Damping factor will be miserable, efficiency will be sub normal, filters of class D won't work correctly etc. etc. Have it your way but you are not on the right rack, sorry. It is based on empirical results and assumptions. One can solve issues by the root which is most effective and has less side effects.
Strongpoint of MA12070 is the very low noise.....
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DF is a hoax 🙂 ans there is EQ
Efficiency is plenty at 110db/w
Filter might be a problem yes - but there is EQ 😉
So I think YOU are wrong!
Well, w'll see when and if I can get one here ... 🙂
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Efficiency is plenty at 110db/w
Filter might be a problem yes - but there is EQ 😉
So I think YOU are wrong!
Well, w'll see when and if I can get one here ... 🙂
//
I need to turn to a more trusted source... will there be any discernible difference in SQ between these... what to get?
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Reread my post, investigate some time in design and working of power amplifiers. I am not wrong, it just does not work that way. EQ does not solve EMI filters not working correctly. In all honesty I think you don't understand jack of amplifiers and electrical properties like power efficiency which I hinted at (which is not loudspeaker efficiency). Even when assuming the speaker to be an 8 Ohm resistor you can calculate what the 18 Ohm series resistor will cause and how loud the amplifier really is playing. Damping factor is a hoax indeed with added 18 Ohm 🙂
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