My MOSFET amplifier designed for music

[von Ah]

 

[Preamp]

From simulation with 100nF in the ic integrator I see a low frequency peak and with 10uF no peak.
What is the right compromise?

There's a little error in your sim schematic. R2 should connect to the negative rail and not to the output.

Try to adjust R21 together with the cap. And have an eye on the settling time, like @brian92fs said.

 

[brian92fs]

For reference, the discussion on the low frequency response hump starts at Post 1455 and extends to post 1490 at a minimum.

 

[rumors]

Sorry, big mistake (I'm visually impaired due to Glaucoma), however, yes, the adjustment increases, so I haven't read everything and I solve the problem by lowering C6 to 47uF

 

[rumors]

Series connection of C1=100n with 220K resistor also seems to work...

 

[rumors]

Adding a 390K resistor on the + - input pins protects the op-amp from high voltages in the event of a fault

 

[Preamp]

Meanwhile my amplifier is now set up in the living room, driving a pair of Infinity's. First impression is superb!

Finished !

And the first impression still holds true. I am not good at answering the question of ''how does it sound?'', but I can say for sure that it sounds different than my other amplifiers, and it certainly sounds pleasing and not fatiguing! It has found its place in my main audio system, and it will stay there.

Some final photos (in rather bad lighting). The front panel was made by Schaeffer AG (or Front Panel Express, for those across the pond). It is anodized in a med-bronze color, which nicely matches the beige color of the case, as well as the champagne color of the Sony player next to it. I really like how it turned out!

 

[brian92fs]

Nicely done!