Suppose one constructing one integrated amplifier to keep it understandable lets say one P3A and one DOZ preamp
Integrated amplifier no one is messing up between amplifier and preamplifier
so there is one coupling capacitor / DC blocking capacitor in the output of the DOZ and one more in the input of the P3A
can we remove one capacitor ?
only one capcitor between the two devices should be enough
any ideas ?
Integrated amplifier no one is messing up between amplifier and preamplifier
so there is one coupling capacitor / DC blocking capacitor in the output of the DOZ and one more in the input of the P3A
can we remove one capacitor ?
only one capcitor between the two devices should be enough
any ideas ?
2 caps in series will be a capacitance lower than the smallest cap of them.
This can make the total cap be unsuitable for the poweramp.
It is like parallell 2 resistors. Two 1 Ohm resistors in parallell will for example giive a resistance of 0.5 Ohm.
This can make the total cap be unsuitable for the poweramp.
It is like parallell 2 resistors. Two 1 Ohm resistors in parallell will for example giive a resistance of 0.5 Ohm.
Theoretically you are right - practically these caps are generally oversized so there is no audible effect to be expected. I guess you will not hear the difference between a 6Hz lowpass going up to 10Hz, for instance.
Removal of the (preamplifier)output coupling capacitor will actually lower the highpass corner frequency, but - assuming that the speakers are capable to reproduce it - neither 10Hz nor 6 Hz are sufficient, it should be below 1Hz.
It is quite possible (even likely IMO) that any coupling capacitor will introduce an audible effect, so removing one that is not needed seems to be basically a good idea.
Since i am designing the PCB there is a few reasons
*one is less expensive parts since both of those capacitors i use are expensive
*saving pcb area is one other
*keeping things simple is one more
*having a better structure is one more keeping the preamp as close to the amp with as less parts possible
thats the idea
i am trying to keep the pcb compact enough to fit a specific enclosure
*one is less expensive parts since both of those capacitors i use are expensive
*saving pcb area is one other
*keeping things simple is one more
*having a better structure is one more keeping the preamp as close to the amp with as less parts possible
thats the idea
i am trying to keep the pcb compact enough to fit a specific enclosure
I would keep both caps in the link ends. An accidental shorcircuit in any of both plugs may damage pre or amp if it has DC component.
;-)
Remove.
Remove every unnecessary part. Because they do modulate the sound very much.
A chance: modification of the sound with different sound-characters of parts.
May be, you do not need a preamp: remove;-)
Remove.
Remove every unnecessary part. Because they do modulate the sound very much.
A chance: modification of the sound with different sound-characters of parts.
May be, you do not need a preamp: remove;-)
if you are designing new PCB (integrated, both pre and PA on one) it entirely dosn't matter which one you omit... I would also, as lineup wrote, remove one on 'preamp side'.... possible complications may arise if one designing amp with separate PCB's for PA and preamp inside one enclosure, and in time he or other tech may forget that cap is missing on one or the other side....
As this isn't an easy question, it depends, I'd say:
If the volume control is between the preamp and power amp section, you need to ensure meticulously to get the preamp output offset voltage as low as possible if the following cap is going to be omitted. Otherwise your amp will make noise when turning the volume up or down.
In the same layout you need to have the power amp input DC current as low as possible if you intend to leave out the input coupling cap after the potentiometer. In addition, total DC resistances need to be equal for the inverting and non inverting inputs with BJT transistors to avoid DC offset at the speaker terminals. Impossible with the potentiometer. In conclusion this only can be recommended with a FET differential input section.
Best regards!
If the volume control is between the preamp and power amp section, you need to ensure meticulously to get the preamp output offset voltage as low as possible if the following cap is going to be omitted. Otherwise your amp will make noise when turning the volume up or down.
In the same layout you need to have the power amp input DC current as low as possible if you intend to leave out the input coupling cap after the potentiometer. In addition, total DC resistances need to be equal for the inverting and non inverting inputs with BJT transistors to avoid DC offset at the speaker terminals. Impossible with the potentiometer. In conclusion this only can be recommended with a FET differential input section.
Best regards!
Without schema analysis, the discussion is meaningless. Both "Yes" and "No" answers can be correct. So it's appropriate to say "Maybe..."🙂
you always need a preamp for low listening levels .... If your listening is more than that you might get away with out it