hi,
I built a little audio mixer and I have a lot of noise on the output, it souds like white noise.
I used a 32768 crystal, is that maybe the reason, do I need some filtering ?
I used the schematics that I found under "typical applications" in the data sheet.
greetings
noise on output of FV-1
Moderator: frank
Re: noise on output of FV-1
Without seeing the board it is impossible to say. Often noise is a result of the layout, ground plane, etc.
Frank Thomson
Experimental Noize
Experimental Noize
Re: noise on output of FV-1
ok sorry,
here is a picture of the schematcs, I made the "insert point" by myself, it could be wrong, maybe the reason for the noise ?
here is the picture link:
https://ibb.co/W6vkPD4
I soldered the output of the preamp to the input of the fv-1 via a 10K poti, because the preamp output was much too hot, and the output I send back to the next amp stage, maybe thats wrong ?
here is a picture of the schematcs, I made the "insert point" by myself, it could be wrong, maybe the reason for the noise ?
here is the picture link:
https://ibb.co/W6vkPD4
I soldered the output of the preamp to the input of the fv-1 via a 10K poti, because the preamp output was much too hot, and the output I send back to the next amp stage, maybe thats wrong ?
Re: noise on output of FV-1
We need to see the physical board, most noise issues have nothing to do with the schematic and are board layout/wiring issues.
Frank Thomson
Experimental Noize
Experimental Noize
Re: noise on output of FV-1
ok, I made a photo:
here is the url:
https://imgur.com/a/jIgwjOt
on the lower side of the board there are normal lines, no gnd plane
here is the url:
https://imgur.com/a/jIgwjOt
on the lower side of the board there are normal lines, no gnd plane
Re: noise on output of FV-1
No ground plane means noise, without a plane you will have ground loops, etc. Best results are 4 layer boards with a ground and power planes.
All those wires running over the top could be an issue. Try to put all connections at the edge of the board and route them away from the board not over it.
What is mounted on the bottom edge of the board (or the board is mounted to it)? Assuming the board is not shielded and just exposed like this can also be an issue.
All those wires running over the top could be an issue. Try to put all connections at the edge of the board and route them away from the board not over it.
What is mounted on the bottom edge of the board (or the board is mounted to it)? Assuming the board is not shielded and just exposed like this can also be an issue.
Frank Thomson
Experimental Noize
Experimental Noize
Re: noise on output of FV-1
hi and thx for the info.
you mean that the white noise is because of the missing groundplane ? I dont have hum problems or sth like this kind of noise.
I cannot make 4 layer boards just to avoid noise of the fv-1, I could make a 2 layer board with a groundplane, is that egough?
In the datasheet is written, that there must be some kind of lowpass filtering on the output, I have used the 32768Hz crystal, could it maybe this "noise" thing ?
greetings
ps: I dont understand much of electronics, could you maybe take a look at the schematics and tell me, if I did the insertion of the fv-1 the right way into the signal path of the mixer?
you mean that the white noise is because of the missing groundplane ? I dont have hum problems or sth like this kind of noise.
I cannot make 4 layer boards just to avoid noise of the fv-1, I could make a 2 layer board with a groundplane, is that egough?
In the datasheet is written, that there must be some kind of lowpass filtering on the output, I have used the 32768Hz crystal, could it maybe this "noise" thing ?
greetings
ps: I dont understand much of electronics, could you maybe take a look at the schematics and tell me, if I did the insertion of the fv-1 the right way into the signal path of the mixer?
Re: noise on output of FV-1
Impossible to say if that is correct. You state it is from the output of a preamp but for what? A guitar amp? And why is the signal so hot, the FV-1 is a low voltage device not intended to be dropped in the middle of a high voltage circuit.
If it is a tube amp then don't mess with it, dangerous high voltages in there.
Since you say you have very little electronics experience I suggest you not mess with inserting something between amp stages until you know a lot more.
If it is a tube amp then don't mess with it, dangerous high voltages in there.
Since you say you have very little electronics experience I suggest you not mess with inserting something between amp stages until you know a lot more.
Frank Thomson
Experimental Noize
Experimental Noize
Re: noise on output of FV-1
hi,
the input is a guitar or a microphone, no tube amp, just headphone amp section after the insert.
did you look at the schematics ? I just want to know, if my insertion is ok or not, please answer me about this, if you understand electronics, you would help me a lot.
greetings
joachim
the input is a guitar or a microphone, no tube amp, just headphone amp section after the insert.
did you look at the schematics ? I just want to know, if my insertion is ok or not, please answer me about this, if you understand electronics, you would help me a lot.
greetings
joachim