What value is that pot?
Hiss that reduces when you short the input might simply be thermal noise from the resistance of the pot, it would be a surprise with the usual sort of 5-10k that most folks use, but worth checking in case you have a silly value in there.
I am somewhat confused because you have a BTL chip that you say you are running single ended, but I don't see a honking great DC blocking cap at the output?
The PSRR will also be purely crap when operated this way, but you say it is hissing not humming.
Regards, Dan.
Hiss that reduces when you short the input might simply be thermal noise from the resistance of the pot, it would be a surprise with the usual sort of 5-10k that most folks use, but worth checking in case you have a silly value in there.
I am somewhat confused because you have a BTL chip that you say you are running single ended, but I don't see a honking great DC blocking cap at the output?
The PSRR will also be purely crap when operated this way, but you say it is hissing not humming.
Regards, Dan.
I don't know how to measure the dc on the inputs?
It is not big deal, I have a few more chips.
I don't know what is your experience about amplifier dip noise.
I am not sure but I think I hear the dip noise of the amplifier itself.
Datasheet indicates output noise is:
0.30(typical) and 0.70mVrms max for Rg=0ohm,BW=20hz to20khz.
I also want to learn your listening experience.
I generally check the noise level with a empty(no music in it) flac file from my computer and I listen my ears very close to speakers.
Also nothing connected amplifier input and shorted its input,and I check the amplifier dip noise..
If a little noise is quite normal, everyone listening(checking) his amplifier, will hear a dip noise probably from tweeters.?
I am not sure but gainclone amps are quite amplifiers and their output noise levels is about 30-40micro volt.
It is not big deal, I have a few more chips.
I don't know what is your experience about amplifier dip noise.
I am not sure but I think I hear the dip noise of the amplifier itself.
Datasheet indicates output noise is:
0.30(typical) and 0.70mVrms max for Rg=0ohm,BW=20hz to20khz.
I also want to learn your listening experience.
I generally check the noise level with a empty(no music in it) flac file from my computer and I listen my ears very close to speakers.
Also nothing connected amplifier input and shorted its input,and I check the amplifier dip noise..
If a little noise is quite normal, everyone listening(checking) his amplifier, will hear a dip noise probably from tweeters.?
I am not sure but gainclone amps are quite amplifiers and their output noise levels is about 30-40micro volt.
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It is 10k pot.
Channels internally bridged inside the chip and I use one channel inside the chip..You should use simple words I don't understand easily.Even drawing this pcb with diptrace was diffucult for me
I'm not surprised you here some noise from that chip, those noise figures are high, putting your ear close to the speaker magnifies it as well, like putting your ear to a shell and hearing the sea
Haha nice comparison
sometimes I also think that way.Can you give me an example like this:
I have an XX amp and I shorted its inputs and hooked it up to speakers.And I can hear the ******* a hiss noise from tweeter or speakers while my ears were very close..
Or maybe you don't hear because somehow crossover network filter this noise maybe?
I use single driver 5inch old fostex drivers..
Do you know amplifiers with fancy output noise figures?
Let's say we have good ears(I don't know what the **** this means) what is the enough noise figures for amplifiers??
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thanks,I already read somewhere in this forum you mentioned you use gnd planes especially for preamp sections and if it is possible also for power amp sections.
I started the draw with diptrace because it was easy at first.But it comes to do a little complicated things,I couldn't find a way to do them with diptrace.So I didn't use gnd plane this time..
I changed one of the chip(L) with new one.Other channel which I shorted its input cap is unchanged.
New chip output 3mV other ch is a little high like 170mV Suprisingly I couldn't observe any damage to the speakers.
Hiss sound I hear same for both chs.Of course there is a noticeable sound degradation on right ch.
New chip output 3mV other ch is a little high like 170mV
Suprisingly I couldn't observe any damage to the speakers.Hiss sound I hear same for both chs.Of course there is a noticeable sound degradation on right ch.
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