Me = relative noob with a good dose of the diyhifi modding bug.
I have been gradually modding a Rotel 965bx. I've ended up with both the standard one that I am modding and a Discrete that I will keep vanilla save for disconnecting the discrete transistor output stage (daughter board) from the muting circuit that remains on the mother board (have also just bought another standard one for a unmodded spare!).
Done a few lightweight mods until now but have just started my first time swapping a few op amps
Original is NE5534s (which I may just return to)
The OPA604 plays nicely
BUT the LME49720 seem to have a much lower volume?
Leaving the volume knob at the same level as it as when listening to the other two sets (5534 & 604) these 49720 are much softer.
Is this volume difference normal?
I can imagine they sound less lively too? Veiled? But haven't listened/compared too closely because firstly, it's this significant difference in volume that has me wondering.
Am I just hearing the characteristics of this opamp in this circuit?
OR did I damage them (static?) when they first went in?
I imagine with an IC like this if you damage it, it either works or it doesn't - you don't get degraded sound just no sound if you messed it up?
Thanks in advance to my respondents.
I have been gradually modding a Rotel 965bx. I've ended up with both the standard one that I am modding and a Discrete that I will keep vanilla save for disconnecting the discrete transistor output stage (daughter board) from the muting circuit that remains on the mother board (have also just bought another standard one for a unmodded spare!).
Done a few lightweight mods until now but have just started my first time swapping a few op amps
Original is NE5534s (which I may just return to)
The OPA604 plays nicely
BUT the LME49720 seem to have a much lower volume?
Leaving the volume knob at the same level as it as when listening to the other two sets (5534 & 604) these 49720 are much softer.
Is this volume difference normal?
I can imagine they sound less lively too? Veiled? But haven't listened/compared too closely because firstly, it's this significant difference in volume that has me wondering.
Am I just hearing the characteristics of this opamp in this circuit?
OR did I damage them (static?) when they first went in?
I imagine with an IC like this if you damage it, it either works or it doesn't - you don't get degraded sound just no sound if you messed it up?
Thanks in advance to my respondents.
From datasheet:
LME49720 - differential input impedance - 30kohm
NE5534 - input resistance - 100kohm
OPA604 - input impedance - too high to matter because FET input stage
What is the value of your potentiometer and any resistor and stuff? Go do some calcs and see if you indeed end up with a 6dB difference in volume.
LME49720 - differential input impedance - 30kohm
NE5534 - input resistance - 100kohm
OPA604 - input impedance - too high to matter because FET input stage
What is the value of your potentiometer and any resistor and stuff? Go do some calcs and see if you indeed end up with a 6dB difference in volume.
Measure the new output and the unmodded output using a standard input tone signal.
The circuit around the opamp should determine the gain. The opamp gain could be around 100000times (one hundred thousand) and needs to be brought down to a usable level around 1times to 10times using the circuit and the feedback.
The circuit around the opamp should determine the gain. The opamp gain could be around 100000times (one hundred thousand) and needs to be brought down to a usable level around 1times to 10times using the circuit and the feedback.
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