200W MOSFET CFA amp

[vac231]

For electrolytic capacitors in PS regulator, which voltage rating ?

 

[dadod]

For electrolytic capacitors in PS regulator, which voltage rating ?

63 V is good enough.

 

[dadod]

Look the evolution of this amp, now with balanced input, new thread http://www.diyaudio.com/forums/solid-state/289933-100w-cfa-mosfet-balanced-input.html#post4682489

 

[dadod]

Finished 100W version with two PS Regulators, similar to dual mono.
Singing beautifully.

 

[platon.rado]

Very nice Dadod

 

[dadod]

Very nice Dadod

How is going over there? I would like to hear some opinion from others.

 

[dadod]

I have designed higher power version of the PS Regulator and it uses a MOSFET as regulating transistor.
It uses IRFP140/9140 MOSFETs and can source up to 20 A before electronic fuse was triggered.
I would need two of them but as the PCB order cost less in more quantity I would like to hear if more interested for double side PCB, dimension is 120x115 mm.
Damir

 

[platon.rado]

Hi Dadod.
Amplifier works.The sound is fantastic.One of the best.Bias 100mA ,dc offset 2,8mV

CFA 100W DAMIR and SLEWMASTER OPS 2pair BJT-IPS Krypton and NX amp are best amplifier I have heard.

Damir, I thank you for the great amplifier...

 

[dadod]

View attachment 546587

Hi Dadod.
Amplifier works.The sound is fantastic.One of the best.Bias 100mA ,dc offset 2,8mV

CFA 100W DAMIR and SLEWMASTER OPS 2pair BJT-IPS Krypton and NX amp are best amplifier I have heard.

Damir, I thank you for the great amplifier...

I am glad you like it.
You can try with somewhat higher bias of about 130 mA, and tell if there any sound different.

I can see that you stil use metal oxide feedback resistors R37/R9( if I am not wrong 5%), better use metal film 1% there.

 

[platon.rado]

Ok..I will do it.thanks

 

[Tesla Audio]

Now is time to replace my old Rod Elliott (ESP)3A project amplifiers with new Damir CFA's. 3 channels are ready for test for my active 3way speakers. Bias is adjusted to 140mA. I recommend to put amplifier on heatsink before adjusting. Sound is absolutely perfect, no noise, no hum.

 

[Tesla Audio]

Some photos

 

[platon.rado]

nice

 

[mlloyd1]

indeed, they are!

mlloyd1

nice

 

[miro1360]

I have found one error in the schematic and the same in the BOM. For the capacitance multipliers (Q9 and Q10) BC546/556 is not good enough, to low Vce. It should be BC546B/BC556B instead.

What function performs C3 on output (schematic 10n, bom 2n2)?

 

[miro1360]

Damir,i have Q9,10 BC547B and BC557B

if voltage on your amp is more than +-45V you need BC546B/BC556B

 

[AndrewT]

(Q9 and Q10) BC546/556 is not good enough, to low Vce. It should be BC546B/BC556B instead.

the last "B" in BC546B and BC556B is the hFE grade.

The 6 in both (BC546/556) is the Vce0 definer.
BC546 and BC556 are both 60Vce0 (Fairchild state 65Vce0), whereas the BC548/549 and BC558/559 are 30Vce0 and BC547/550 and BC557/560 are 45Vce0

 

[SERGIODS]

Here is the last 200W-CFA-VMOSFET zip file with .asc and models files.
Damir

What software to use?

 

[miro1360]

thanks Damir for this amp, sounds great, I am testing it and it give really nice dynamic in lows, big space in mids, highs are clean - like others said here
Now I prefered caps mica, with pp can sounds different ...

 

[dadod]

What software to use?

LTspice, free software from Linear Technology Linear Technology - Design Simulation and Device Models