Hi.
If using single end connection to an amplifier with RCA connectors we have a common ground for both left and right channel.
Now, my question is like this : is there any problems using dual passive attenuators regarding channel separation in such single end configuration.
As we can see at the picture, attenuating 20dB for both channels using two Monacor attenuators will look like this :
Source impedance at the schematic input is 500 Ohm.
Impedance at amplifier is 27 kOhm.
We see the common ground between both channels .
Now, using passive attenuators:
R1 is 10Kohm and R2 is 1Kohm with each of the two attenuators.
Is there a channel separation bleeding between left and right channel using those attenuators and if there is, how big is the problem ?
If using single end connection to an amplifier with RCA connectors we have a common ground for both left and right channel.
Now, my question is like this : is there any problems using dual passive attenuators regarding channel separation in such single end configuration.
As we can see at the picture, attenuating 20dB for both channels using two Monacor attenuators will look like this :
Source impedance at the schematic input is 500 Ohm.
Impedance at amplifier is 27 kOhm.
We see the common ground between both channels .
Now, using passive attenuators:
R1 is 10Kohm and R2 is 1Kohm with each of the two attenuators.
Is there a channel separation bleeding between left and right channel using those attenuators and if there is, how big is the problem ?
Ok, so this chain is 100 % transparent to not using attenuators ?
No difference in soundquality except 20dB attenuation of the signal ?
Source output impedance : 500 Ohm
Two RCA Attenuators ( for L and R ) at the input of the amplifier : each have 10 kOhm in series, and shunted to 1 kOhm to common ground .
Amplifier impedance : 27 kOhm
No difference in soundquality except 20dB attenuation of the signal ?
Source output impedance : 500 Ohm
Two RCA Attenuators ( for L and R ) at the input of the amplifier : each have 10 kOhm in series, and shunted to 1 kOhm to common ground .
Amplifier impedance : 27 kOhm
Another question : where to put the two RCA input coupling capacitor at the amplifier side ? Before or after the attenuators ?
I ask, because I may solder 4 resistors to make the attenuation, instead of using the two monacors.
I ask, because I may solder 4 resistors to make the attenuation, instead of using the two monacors.
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Audio signal from input jack goes through the resistor or resistors to the ground. No futher. End of story. Does not matter the value of the first or second resistor.
Next stage amplifies what's on second resitor. Nothing else.
No loss in signal quality. However resistor do have thermal noise.
On the other hand, normal volume pot is nothing else than two variable resistors whose sum of resistance is constant.
On the other hand, normal volume pot is nothing else than two variable resistors whose sum of resistance is constant.
Coupling capacitors at input of the poweramplifier board, before line driver opa1612. The value was 3,3 uF before, but I will switch to two 4,7 uF polycaps.
I wonder if soundquality will be better with the attenuation done before the capacitor or after . No difference ?
I wonder if soundquality will be better with the attenuation done before the capacitor or after . No difference ?
