Hi everyone, I am tube diy but I want to try building a LM3886 amp. I ordered the stereo pcb set from Brian at chipamp.com. My question is regarding the feedback resistor, in tube design I usually like the non feedback designs but can anyone tell me if you have been listening to the LM3886 with and without the feedback. I am not interested in distortion, I read about National data and measurements made by several guys, I want listening opinions.
Thanks.
Thanks.
Sorry, rereading the manual, I realise he is talking about a feedback capacitor, not a resistor.
The assembly manual gives 2 options, I quote:
- for using the standard configuration, R3 is installed as shown on the right.
-for using the feedback capacitor, R3 is installed as shown on the left.
As for the preferred configuration, the standard configuration has been said to sound better, but lower dc offset can be obtained through using the feedback capacitor.
R3 is the 680 ohm setting the gain with 22K feedback resistor.
So has anyone been listening to the different configurations?
The assembly manual gives 2 options, I quote:
- for using the standard configuration, R3 is installed as shown on the right.
-for using the feedback capacitor, R3 is installed as shown on the left.
As for the preferred configuration, the standard configuration has been said to sound better, but lower dc offset can be obtained through using the feedback capacitor.
R3 is the 680 ohm setting the gain with 22K feedback resistor.
So has anyone been listening to the different configurations?
hi.
http://chipamp.com/docs/lm3886-manual.pdf
If you use the optional 47uF Capacitor, which is standard for LM3886 typical circuit,
you may have less problems with DC-offset at the output.
You can read about and see this in the LM3886 datasheet:
http://www.national.com/ds.cgi/LM/LM3886.pdf
My opinion: You will not be able to hear any diffrence in sound.
Cap or no cap.
So my advice would be to try without, if you wish.
But then measure the DC-offset at output, with different volume potentiometer settings.
You will then see if you need to use this CAP 47uF.
http://chipamp.com/docs/lm3886-manual.pdf
If you use the optional 47uF Capacitor, which is standard for LM3886 typical circuit,
you may have less problems with DC-offset at the output.
You can read about and see this in the LM3886 datasheet:
http://www.national.com/ds.cgi/LM/LM3886.pdf
My opinion: You will not be able to hear any diffrence in sound.
Cap or no cap.
So my advice would be to try without, if you wish.
But then measure the DC-offset at output, with different volume potentiometer settings.
You will then see if you need to use this CAP 47uF.
In fact it depends on what cap you use for that...
If youre talking about Nichicon Muse Gold and Elna Silmic compared to an average elco cap theyre really impressive and good sounding ones.
However I personally prefer no cap... I have tested all these options and saw the most transparent option is no cap. The others may add some "spice" or their own "aroma" to the sound. But just that, I hear no additional distortion or noise with Ci...
If youre talking about Nichicon Muse Gold and Elna Silmic compared to an average elco cap theyre really impressive and good sounding ones.
However I personally prefer no cap... I have tested all these options and saw the most transparent option is no cap. The others may add some "spice" or their own "aroma" to the sound. But just that, I hear no additional distortion or noise with Ci...
Build the two channels to different philosophies.
The Left channel as a DC coupled amplifier. The right channel as an AC coupled amplifier.
Hide the two channels from view inside a metal chassis.
Come back after a few years and tell us which channel blew up your speaker first.
Then review which channel now sounds better. The silent one, or the working one.
The Left channel as a DC coupled amplifier. The right channel as an AC coupled amplifier.
Hide the two channels from view inside a metal chassis.
Come back after a few years and tell us which channel blew up your speaker first.
Then review which channel now sounds better. The silent one, or the working one.
Unhelpful, patronizing, sarcasm.......... WELL DONE!
Just wasted 20 seconds of my life reading it!
It is intended to be a warning to those that might be tempted and misguided enough to try doing it incorrectly.
But then I am accused of posting unhelpful posts.
It obviously depends on the attitude and bias of the reader on whether it is helpful or unhelpful.
BTW,
there is an argument that could arrive at the conclusion that the silent channel performs better than that which is producing noise.
But then I am accused of posting unhelpful posts.
It obviously depends on the attitude and bias of the reader on whether it is helpful or unhelpful.
BTW,
there is an argument that could arrive at the conclusion that the silent channel performs better than that which is producing noise.
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