Ryssen may be one step back in discussion....
What is the voltage after the resistor network when you have on the other side the 2.83V?
Means the voltage going into the soundcard....
Picture looks now much better! Did you get your SS from Semisouthfan?
And where can you read your THD in numbers? I saw no display showing this value.
Maybe you must switch it on.
But the new picture is fairly good k2 around 6db higher than K3 is a possible keeper if you like the sound.
Nevertheless it stays of some importance to know what AC 1kHz voltage is really coming in the soundcard....5mV or 150mV gives different THD values.
Normally with these resistor network you should be near to 200mV. This is a good value, but please check.
What is the voltage after the resistor network when you have on the other side the 2.83V?
Means the voltage going into the soundcard....
Picture looks now much better! Did you get your SS from Semisouthfan?
And where can you read your THD in numbers? I saw no display showing this value.
Maybe you must switch it on.
But the new picture is fairly good k2 around 6db higher than K3 is a possible keeper if you like the sound.
Nevertheless it stays of some importance to know what AC 1kHz voltage is really coming in the soundcard....5mV or 150mV gives different THD values.
Normally with these resistor network you should be near to 200mV. This is a good value, but please check.
Yes I can adjust the level and signal.
How much is the 2k supposed to be changed when I turn the pot?Is it 5db or more?Cause the spectrum is moving a little all the time..
You mean the pots over the source resistors, you have 0R1 as source resistor?
And you have a 10R pot over the source resistors.?
Then you could expect a change of +- 12 db.
When the two Semisouth are in balance, means k2 minimum and k3 dominance.
When one SS has more transconductance the range of the pots is of course reduced to compensate this mismatch...
When I interpret your diagram right distortion is still to high....
K2 and k3 peaks are only 45 -50 db lower than the 1kHz peak, 60 db is better....
Please try also for free
ARTA or Visual Analyser. with your knowledge now you should handle them in a short time.
Did you put your program to 24 bit and at least 48kHz?
What window? Hanning?
K2 and k3 peaks are only 45 -50 db lower than the 1kHz peak, 60 db is better....
Please try also for free
ARTA or Visual Analyser. with your knowledge now you should handle them in a short time.
Did you put your program to 24 bit and at least 48kHz?
What window? Hanning?
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I thought they could come from Semisouthfan because my friend Oliver had nearly the same k2/k3 distribution with his Semisouthfan parts.
This distrubution shows a very good matching of the parts.
Look for Blackman or google and look at the descriptions for advantages or disadvantages of the different windows....
But you picture shows 44kHz or did my old eyes cheat me...
Distortion 0.37 % is still too high but would correspond to the 40 to 45 db distance from 1kHz peak to the two others.
More normal would be 10 times better 0,035%
But I do not know what Mod Distortion is, the 0.00O7% ?....
So I am still uncertain...
My friend Oliver had with ARTA and his SS 0,0095%
But I believe these soundcard measurements show too low absolute values....
But in your case what is the difference between the two distortion values, how does your program explain the words?
More normal would be 10 times better 0,035%
But I do not know what Mod Distortion is, the 0.00O7% ?....
So I am still uncertain...
My friend Oliver had with ARTA and his SS 0,0095%
But I believe these soundcard measurements show too low absolute values....
But in your case what is the difference between the two distortion values, how does your program explain the words?
Here´s what I find:
Measurement method THD+N
The fundamental wave is removed from the frequency spectrum, then have the effective voltage value over harmonics d2 and the noise between the frequencies 'low' and 'high' are summed. Then this value is divide by the total effective voltage value ( that means with the fundamental wave and without any frequency spurs ) now you get the THD+N.
Measurement method Inter modulations Distortions
Please select in the sound dialog Dual Sine and enter at freq/Hz the main frequency ( eg. 7kHz ) and at Second frequency the interfere frequency
( eg. 60Hz ). The IEC 268 Part 3 says that the interfere frequency should be 12db louder than the main frequency.
Eg. dig Level = -15dB second dig. Level = -3dB
Measurement method THD+N
The fundamental wave is removed from the frequency spectrum, then have the effective voltage value over harmonics d2 and the noise between the frequencies 'low' and 'high' are summed. Then this value is divide by the total effective voltage value ( that means with the fundamental wave and without any frequency spurs ) now you get the THD+N.
Measurement method Inter modulations Distortions
Please select in the sound dialog Dual Sine and enter at freq/Hz the main frequency ( eg. 7kHz ) and at Second frequency the interfere frequency
( eg. 60Hz ). The IEC 268 Part 3 says that the interfere frequency should be 12db louder than the main frequency.
Eg. dig Level = -15dB second dig. Level = -3dB
Here we have it soundcard is too bad I suppose having itself 0,19 THD, much too much.....
Take the 0.21 of audio Analyser and substract the 0.19 of soundcard so you have a good value of 0.02 for the Amp a believable value.
Means you need a good USB soundcard like Buzz the EMU 4-4
Or you are content with the results you get by subtracting the k2 and k3 of the soundcard...
Not very precise, but if you only want to adjust k2/k3 ratio this may be sufficient for the moment.?