A transistor based, standalone, differential preamplifier without a general, input to output feedback has been made.
Again : This is NOT an operational amplifier. There is no continuous DC path from input to output and, most importantly, there is no any general, output to input feedback.
There are input JFET buffers, an NPN, differential pseudo buffer, an NPN, standalone, differential amplifier and a PNP and NPN output buffers. All these made of transistors only. No IC's. No operational amplifiers. There are a few high pass and a low pass filters among these functional blocks.
The noise is insignificant even at maximum gain and, even, with non regulated ( but, audio transformer and audio capacitors based ) power supply.
The sound is majestic, yet, probably, so majestic, so, I think, I suffer from sound quality hallucinations. I have noticed these with other transistor projects too.
However, to have discrete transistors or tubes sound better than an operational amplifier is physically impossible, hence, these are, only, hallucinations.
The schematics and the pictures are in the addendum. Scroll all the way down to see them.
Here is the document :
Transistor Based, Standalone, Differential Preamplifier - Google Drive
Again : This is NOT an operational amplifier. There is no continuous DC path from input to output and, most importantly, there is no any general, output to input feedback.
There are input JFET buffers, an NPN, differential pseudo buffer, an NPN, standalone, differential amplifier and a PNP and NPN output buffers. All these made of transistors only. No IC's. No operational amplifiers. There are a few high pass and a low pass filters among these functional blocks.
The noise is insignificant even at maximum gain and, even, with non regulated ( but, audio transformer and audio capacitors based ) power supply.
The sound is majestic, yet, probably, so majestic, so, I think, I suffer from sound quality hallucinations. I have noticed these with other transistor projects too.
However, to have discrete transistors or tubes sound better than an operational amplifier is physically impossible, hence, these are, only, hallucinations.
The schematics and the pictures are in the addendum. Scroll all the way down to see them.
Here is the document :
Transistor Based, Standalone, Differential Preamplifier - Google Drive