Class D Design Issues

I would just like to say that I have read a lot of your posts from everyone and I'm amazed and envy everyone's knowledge to make circuits. I think, but I might be wrong. Amps are the easiest of all components to make. ( compared to like tuners and CD players, etc. )But to still have the no-how to make amps is beyond me. How did you guys get that knowledge? I would really like to know. I have been a fan of high end equipment for years and I would like to know what components do what in a circuit. I just don't no where to start .
 
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Hello. Since i don't want to litter diyaudio with new threads, i will ask in this one.
It is not truly about designing class d amplifier, but very close. I couldn't find any info on this:
So i have a few questions:

1. Can soft dome tweeters be driven of filterless? I dont know what "soft dome" means, thats only info about them. Maybe i need to add output filter (which kinda makes this into class D designing :D)

2. I only have one free pam8403 channel for them, and they make 2 ohm load, while pam8403 designed for 4ohm, could it work with high pass at aprox 6000hz because power is very low that high?
I could add 1.2 ohm resistor to reach 3.2ohm load, it would be still louder than series speakers. Only if its needed of course.

Thanks in advance, and sorry for invading thread :D
 
Mini amp repair.. wrong parts?

Hey guys, still pretty new to all this.

So, I accidentally pulled the shaft out of one of my pots while trying to remove the knobs. I replaced a B100k with a B100k on the balance knob. Now it acts as another volume knob. All of them read B100k, so I don't understand why it's not doing the same thing it did before.. any ideas?

This picture is of a new one that I ordered with it's original pots. The one with the green sticker is the balance. What is different about this pot so I can repair the other one with the right part?

Thanks for any insight!

sorry it's sideways :D
An externally hosted image should be here but it was not working when we last tested it.
 
Sorry, I forgot to mention. The amp is the Kinter MA-180 and there are four knobs and a power switch.. volume, bass, treble, and balance. :beady:


Hey guys, still pretty new to all this.

So, I accidentally pulled the shaft out of one of my pots while trying to remove the knobs. I replaced a B100k with a B100k on the balance knob. Now it acts as another volume knob. All of them read B100k, so I don't understand why it's not doing the same thing it did before.. any ideas?

This picture is of a new one that I ordered with it's original pots. The one with the green sticker is the balance. What is different about this pot so I can repair the other one with the right part?

Thanks for any insight!

sorry it's sideways :D
An externally hosted image should be here but it was not working when we last tested it.
 
I've always wondered why my Behringer NU3000DSP class D amp sounds so flat in the treble, so I decided to measure it acoustically (noise) connected to my ribbon speakers.

I normally use it as a bass amp, where it's doing a great job.

As you can see, on the red line, there's a whole lot of noise in the treble and very poor phase behaviour. Its the same on both channels, and the amp is setup in
straight mode without the DSP in operation.

For comparison, the blue graph is from a Nad M3.

Can the problem be due to a much to low modulator frequency?
 

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