There are plenty of way to arrange input stage in a current feedback amp.
I have seen many. Standard is 4 transistors in a Diamond type figuration.
But also used is 2T and a bunch of resistors in a network.
The way I show in diagram uses 2T and 2 Current sources.
I have never seen this way before, so this I have figured it out myself.
But to me this method is rather obvious, so I think this must have been done before.
The heart is within the smaller rectangle.
2 current sources creates 0.6V across R3 and R13, 47 Ohm.
To get a good gain in first stage I use rather much current, 14 mA and 47 Ohms resistors.
R8 and R7, 150/10 Ohm sets the Gain of amp. Here we have x16
Current Feedback comes to R8.
I keep feedback resistance low in order to get low distortion.
VAS is only a pair of BC556/BC546 working at 5 mA
Output stage in the bigger rectangle is very standard.
Quiescent current for MJL3281/1302 is at 50 mA
Amplifier shows good performance. 25 Watt in 8 Ohm.
What is special for CFA amplifiers is the speed.
And this one shows stable -3dB at around 4 MHz
So it is very fast.
I have seen many. Standard is 4 transistors in a Diamond type figuration.
But also used is 2T and a bunch of resistors in a network.
The way I show in diagram uses 2T and 2 Current sources.
I have never seen this way before, so this I have figured it out myself.
But to me this method is rather obvious, so I think this must have been done before.
The heart is within the smaller rectangle.
2 current sources creates 0.6V across R3 and R13, 47 Ohm.
To get a good gain in first stage I use rather much current, 14 mA and 47 Ohms resistors.
R8 and R7, 150/10 Ohm sets the Gain of amp. Here we have x16
Current Feedback comes to R8.
I keep feedback resistance low in order to get low distortion.
VAS is only a pair of BC556/BC546 working at 5 mA
Output stage in the bigger rectangle is very standard.
Quiescent current for MJL3281/1302 is at 50 mA
Amplifier shows good performance. 25 Watt in 8 Ohm.
What is special for CFA amplifiers is the speed.
And this one shows stable -3dB at around 4 MHz
So it is very fast.