hi Hans
sorry no idea..
1 is it possible to split the channels to try out which of these channles make this strange nois after a while.
2 this strange noise is not at the starting - so it comes during some time - for me its sound about som chip/cap/diode/resistor gets warm and then the nighmare starts
chris
If you connect all inputs to one pre-amp-out and have no input cap and no input resistor for every input, the 6 amps may oscillate because you connect them over the input.
Put one 1.0-2.2uF cap at each amp input, in series with a 1k ohm resistor. Now you may connect your pre-amp to the other side of the 1k ohm resistors as you like.
If this cures your problem, you should calculate how this DC filters frequency response is, as this depends on the input resistors values.
To explain it: You took the amp´s out of an AV receiver. You did not change anything in the output stage. So this should be OK.
Inside the AVR each amp was hooked to it´s own input buffer. These are missing and may be your problem now. The C and R should separate the inputs from each other.
PS doesn´t matter which exact quality and value the C and R might be. For a test might be .47uF and 1-4k ohm as well. If you go too small in capacitors, the low frequency might suffer, to much ohm and volume will get lower. This is not critical, you can not ruin anything.
Put one 1.0-2.2uF cap at each amp input, in series with a 1k ohm resistor. Now you may connect your pre-amp to the other side of the 1k ohm resistors as you like.
If this cures your problem, you should calculate how this DC filters frequency response is, as this depends on the input resistors values.
To explain it: You took the amp´s out of an AV receiver. You did not change anything in the output stage. So this should be OK.
Inside the AVR each amp was hooked to it´s own input buffer. These are missing and may be your problem now. The C and R should separate the inputs from each other.
PS doesn´t matter which exact quality and value the C and R might be. For a test might be .47uF and 1-4k ohm as well. If you go too small in capacitors, the low frequency might suffer, to much ohm and volume will get lower. This is not critical, you can not ruin anything.
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.