A LM3886 "Stasis" Power Buffer

[carlmart]

There was a power-amp by Musical Fidelity, model A370, that also used an LM318 on the first stage, boosted by ten MOSFETs at the output.

Apparently it was class-A, but I am not too sure of that. It was released in the mid '80s, if I am not wrong, and it seemed to get good reviews.



Carlos

[mauropenasa]

Hi, Carlos
I have quoted the similes with my circuit of A370 here:

MY_REF technical description

The mosfets are polarized to 1A total, then it's class AB...

This circuits are not "STASIS"...

ciao

Mauro

[rkn]

Hi Mauro and all other,

I've seen Mauro's work here and find it quite intersting to build the PC/CC. Therefore, I made a PCB layout and etched them yesterday. Now I'm waiting for the parts to stuff the board. I'll inform you about the results then as soon as possible.

Raphael

[Redshift187]

This is very fascinating. Am I understanding the basics correctly:

First stage: a voltage gain stage without current gain, as current gain affects noise

Second stage: a current gain stage operating on the high signal to noise ratio produced by the first stage

[soongsc]

Originally Posted by rkn

Hi Mauro and all other,

I've seen Mauro's work here and find it quite intersting to build the PC/CC. Therefore, I made a PCB layout and etched them yesterday. Now I'm waiting for the parts to stuff the board. I'll inform you about the results then as soon as possible.

Raphael

Very interesting. Hope to hear more on the results!

[UnixMan]

I have tried a different yet similar approach. I have prototyped the circuit shown below using an LM3875. It works just fine (and sounds very good, too!) using a tube "front-end" (actually a 12b4 SE preamp!).

The circuit is perfectly stable as far as the drive impedance (Rs) is high enough compared to R1.