Dear All,
Sorry for a newbee questions
I like to know what you guys think with this "upgrade" scenario
Let's just say originally the Tube Pre-AMP has a 1UF capacitor
Can we substitute with some thing close to the original value such as .82UF ?
Is there any sound different?
I knew that the voltage must be the same
Let me know your insight guys
tks
Sorry for a newbee questions
I like to know what you guys think with this "upgrade" scenario
Let's just say originally the Tube Pre-AMP has a 1UF capacitor
Can we substitute with some thing close to the original value such as .82UF ?
Is there any sound different?
I knew that the voltage must be the same
Let me know your insight guys
tks
Do you know the function of the cap? Smooting, coupling, powersupply, etc.
The value of a cap always depends on the surrounding circuitry. Let's assume it's a coupling cap. Combined with the impedance of the next stage, you get a high pass filter with a certain frequency. For example, if the next stage has a impedance of 10k ohm, the -3dB frequency will be 16 hertz. With a .82uF cap, the -3dB point will be 19 hertz. Just 3 hertz. But with a 1k ohm impedance, it's 159 vs 194 hertz. A 35 hertz difference. You might detect a small change in frequency response in the sound of the preamp, but not anything world chaning in my opinion.
If it's a cap e.g. tuned to prevent high frequency oscilations somewhere in the preamp, or part of the EQ network, the change might be more significant though.
The value of a cap always depends on the surrounding circuitry. Let's assume it's a coupling cap. Combined with the impedance of the next stage, you get a high pass filter with a certain frequency. For example, if the next stage has a impedance of 10k ohm, the -3dB frequency will be 16 hertz. With a .82uF cap, the -3dB point will be 19 hertz. Just 3 hertz. But with a 1k ohm impedance, it's 159 vs 194 hertz. A 35 hertz difference. You might detect a small change in frequency response in the sound of the preamp, but not anything world chaning in my opinion.
If it's a cap e.g. tuned to prevent high frequency oscilations somewhere in the preamp, or part of the EQ network, the change might be more significant though.
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The voltage does not have to be the same. It has to be sufficient, under all normal and most fault conditions.
The value depends on exactly how the cap is used in the circuit, whether it sets a rolloff, whether it is within a negative feedback loop etc. A 20% change is unlikely to make much difference.
The value depends on exactly how the cap is used in the circuit, whether it sets a rolloff, whether it is within a negative feedback loop etc. A 20% change is unlikely to make much difference.
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