At the moment my LM3886 amp has an 1uf Wima input cap. There is a recommendation to replace it to 2.2uf MKP cap to get a clearer/more natural sounding vocal.
After my focusrite saffire I'm running the audio through 6j1 tube buffer known as The Fever 6j1 Tube Pre-amp and I have swaped the tube into Voshkod 6ZH1P-EV, it sounds great on my active studio monitor, however on my Wharfedale Diamond 10.1 powered by the LM3886 amp I feel that the vocal and midrange sounds too thick and off.
Based on the article on Tube preamp kit FE-6J1-2.0B | the signal output impedance of The Fever 6j1 Tube Pre-amp is around 3 kilo-ohms.
Please point me into finding the right value for the input cap and understanding the impact of it to the sound. Or should I remove the input cap and by pass it entirely?
After my focusrite saffire I'm running the audio through 6j1 tube buffer known as The Fever 6j1 Tube Pre-amp and I have swaped the tube into Voshkod 6ZH1P-EV, it sounds great on my active studio monitor, however on my Wharfedale Diamond 10.1 powered by the LM3886 amp I feel that the vocal and midrange sounds too thick and off.
Based on the article on Tube preamp kit FE-6J1-2.0B | the signal output impedance of The Fever 6j1 Tube Pre-amp is around 3 kilo-ohms.
Please point me into finding the right value for the input cap and understanding the impact of it to the sound. Or should I remove the input cap and by pass it entirely?
ok, my bad, perhaps my question should be: does the input capacitor give a tonality to the audio signal, would a different value resulted in a more bass or more crunchy sound, or it has nothing to do with tonality and just serve the two purpose: 1. pass audio signal 2. block DC signal
if its too small, then it will cut bass.
if its verry verry small, it has allready cut the bass, and will start cutting midrange.
1uF in most situations is more than enough.
what i would try if i was you is paralell 2 of them to get 2 uF, with better properitys than a single 2 uF one.
but it most likely does not interfer with the midrange at all . 470 nF is usually considered enough for generic cases.
if its verry verry small, it has allready cut the bass, and will start cutting midrange.
1uF in most situations is more than enough.
what i would try if i was you is paralell 2 of them to get 2 uF, with better properitys than a single 2 uF one.
but it most likely does not interfer with the midrange at all . 470 nF is usually considered enough for generic cases.
There are a lot of undefined variables in the scenario you're describing. It would help to know the details of the LM3886 amplifier you're using. Is there a schematic available?
The input capacitor in your LM3886 amplifier, along with the input impedance of the amplifier, will create a high pass filter with a 3dB roll-off frequency (F) determined by:
F = 1 / (2*pi*R*C)
In the attached image, the input impedance of the amplifier is determined (more or less) by the 22k resistor, R7. Using that value, along with the 2.2uF capacitor (C8), gives a roll-off frequency of approximately 3.3 Hz. Frequencies above 3.3 Hz will be passed without attenuation.
If one assumes a 22k Ohm input impedance for your amplifier, the 1uF capacitor will give a roll-off frequency of approximately 7.2 Hz. I don't think changing that capacitor will make much of a difference.
Again, it would be helpful to know more about your amplifier.
The input capacitor in your LM3886 amplifier, along with the input impedance of the amplifier, will create a high pass filter with a 3dB roll-off frequency (F) determined by:
F = 1 / (2*pi*R*C)
In the attached image, the input impedance of the amplifier is determined (more or less) by the 22k resistor, R7. Using that value, along with the 2.2uF capacitor (C8), gives a roll-off frequency of approximately 3.3 Hz. Frequencies above 3.3 Hz will be passed without attenuation.
If one assumes a 22k Ohm input impedance for your amplifier, the 1uF capacitor will give a roll-off frequency of approximately 7.2 Hz. I don't think changing that capacitor will make much of a difference.
Again, it would be helpful to know more about your amplifier.
Attachments
You don't really want the output impedance of the pre-amp to "match" the input impedance of the amplifier. For the amplifier input you are transferring signal, not power. In this case you want the input impedance of the amplifier to be greater than the output impedance of the pre-amp. It may help to set the input impedance of your amplifier to around 50k to 60k, assuming you are staying with the tube pre-amp.
Removing the input capacitor is a bad idea. It blocks DC from entering your amplifier. Unless you can positively guarantee zero DC offset from whatever source you may connect to your amplifier, you run the risk of ruining your speakers.
Agree.
In any case:
All doubling the current 1uF cap will achieve is , as stated above, lower low frequency cutoff frequency .... which already is low enough.
It will NOT affect mid frequencies such as those involved in the voice range, specially since you are worried about them
And since it´s a speaker specific problem, well, then it´s speaker specific !!!!!
Just going by your description the Wharfedale Diamond has more low mids and less highs than the powered monitor.
Which is not a defect, simply you are driving it with a flat honest simple LM3886 amp, while I am *certain* that the active monitor has *complex* built in active EQ, and is very probably biamped, a different beast.
Just check what´s inside this "simple" Yorkville Studio monitor, it´s the "small" one with a 6.5" woofer, a 3/4 " dome tweeter and biamplified with a couple LM3886 , lots of peaks and notches here and there, separate limiting/compression, the works.
http://www.yorkville.com/downloads/servman/sm_ysm1p.pdf
No plain cap replacement will achieve that
In any case:
is a wrong statement (to put it mildly)
All doubling the current 1uF cap will achieve is , as stated above, lower low frequency cutoff frequency .... which already is low enough.
It will NOT affect mid frequencies such as those involved in the voice range, specially since you are worried about them
And since it´s a speaker specific problem, well, then it´s speaker specific !!!!!
Just going by your description the Wharfedale Diamond has more low mids and less highs than the powered monitor.
Which is not a defect, simply you are driving it with a flat honest simple LM3886 amp, while I am *certain* that the active monitor has *complex* built in active EQ, and is very probably biamped, a different beast.
Just check what´s inside this "simple" Yorkville Studio monitor, it´s the "small" one with a 6.5" woofer, a 3/4 " dome tweeter and biamplified with a couple LM3886 , lots of peaks and notches here and there, separate limiting/compression, the works.
http://www.yorkville.com/downloads/servman/sm_ysm1p.pdf
No plain cap replacement will achieve that
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