Three-pole compensated blameless clone

[HRDSTL]

Laco, don't you plan to design a version with a coil on the output of the amplifier?

 

[LKA]

never, the classic output coil is dead to me

 

[brian92fs]

Can you elaborate? Is the design itself accounting for this view or do you find that output coils are generally unnecessary?

 

[LKA]

An output coil is required. I just changed the design. Instead of the classic air coil, I started using the inductance of the wire that connects the amplifier board and the output terminal of the chassis. The amplifier is also designed so that 0.1uH inductance is sufficient for stability. ( PM > 60 deg, GM > 15dB, stable into 15nF II 4R load without coil).
IMHO, If you are aiming for the -120dB thd level, it is better to have the coil outside the amp pcb.

 

[LKA]

MOSFET updated schematic

 

[minek123]

Is this a triple output? What is the function of Q1/Q4 ?

 

[HRDSTL]

short-circuit protection, ...

 

[LKA]

Is this a triple output? What is the function of Q1/Q4 ?

yes, triple. Q1,Q4 are error correction transistors [not my invention ]

 

[LKA]

spectrum 100W 4R 20k

 

[minek123]

LKA, if I want to add one more pair of output devices, do I need to increase drivers/predrivers current?
25mA seems like enough for 3 pairs or even 4?
Are you sure 2 pairs will handle 200W at 4 Ohms?

 

[LKA]

yes, you can add one more pair.
sure, two pairs of IRFP240/9240 can handle 200W/4R (no secondary breakdown, DC SOA 100V 1,5A )

 

[Ultima Thule]

Cosmos ADC is optimized for 1kHz, at 10k(20k) it has "weak" performance.

I am curious about this statement, do you think the relatively poorer performance at 10k is specifically related to Cosmos ADC than what is generally observed with other ADC's, do you have any idea what may be the reason?

 

[LKA]

I have no idea

 

[MarcelvdG]

I don't know if this is relevant, but sigma-delta audio ADCs often have the noise increase quickly above 20 kHz.

 

[bohrok2610]

ES9822PRO used in CosmosADC has flat noisefloor up to about 200kHz. I don't have CosmosADC but with my own ES9822PRO ADC I can measure down to -130dB @10kHz.