DC Servo MOSFET Amplifier

[apexaudio]

Final Version F100 Hitachi

R8 & R9 = 2k2/1W

Great job, I must say many people like your pcb design more than my, it's look more like DIY, and more expensive becouse larger size, thank's for shareing.
Regards

 

[apexaudio]

Space for heatsink 15mm over PCB, wholes for heatsink connect 7,5mm distance from pcb margin. Soldering outputs after montage and connect heatsink and pcb.

 

[vijay_meyou]

Great job, I must say many people like your pcb design more than my, it's look more like DIY, and more expensive becouse larger size, thank's for shareing.
Regards

Hi apex,

coolet routing is amazing! but i won't agree that every one started liking his design. your designs are very proffesional space saving and very good traces with appropirate widthes. i always stick with your pcb layout because its almost half the size of coolets design.and i feels its good for DIYers.

Vijay

 

[apexaudio]

Hi apex,

coolet routing is amazing! but i won't agree that every one started liking his design. your designs are very proffesional space saving and very good traces with appropirate widthes. i always stick with your pcb layout because its almost half the size of coolets design.and i feels its good for DIYers.

Vijay

Not every one, beginners in DIY have better look on his design becouse of size and colours, my design confuse beginners, and there is much more beginners than experts, and there is some people who want just clone expensive brand to get better price for sale clone, and don't want learn anything.
Regards

 

[coolet]

i just simply followed design rules to avoid crosstalk. one hint is nfb must be at the correct point if you can see it. making money for diy is not my case it is just my fast time. if it is digital design I can make it as small as you can imagine.

 

[apexaudio]

i just simply followed design rules to avoid crosstalk. one hint is nfb must be at the correct point if you can see it. making money for diy is not my case it is just my fast time. if it is digital design I can make it as small as you can imagine.

Coolet,
Your pcb design is great, you share your design, and thank's for that. Making money is not your case for sure, for people who want build 'Goldmund' clone without basic knowlage and without any expirience in DIY, I'm not sure
Regards

 

[coolet]

Is this ok? 15mm and 7mm

 

[AndrewT]

why are the output FETs so far away from the components feeding them?

In particular, the big distance you have designed in, puts the gate resistors Xcm away from the gate terminal.

 

[coolet]

why are the output FETs so far away from the components feeding them?

In particular, the big distance you have designed in, puts the gate resistors Xcm away from the gate terminal.

see post 162.. it was requested by mr. apex to mount the fets reverse underside.

 

[AndrewT]

that is not a reasonable excuse for these long traces feeding the FETs.

They can usefully be designed shorter than those shown in post162.

 

[apexaudio]

that is not a reasonable excuse for these long traces feeding the FETs.

They can usefully be designed shorter than those shown in post162.

Horisontal montage can be short same as vertical, looking to other DIY project evan shorter.

 

[apexaudio]

FB100

MOSFET/BJT Hybrid Amplifier

 

[apexaudio]

MOSFET/BJT Hybrid Amplifier

Many audiophiles think that amplifier with MOSFET/BJT hybrid output stage have better sound compare with all MOSFET output stage amplifiers.

 

[mathez]

Hi Apex,i hve finshed my F100,how set bias for sk1058

 

[apexaudio]

Hi Apex,i hve finshed my F100,how set bias for sk1058

If you use schematic from post #123, set bias with R22 (1k pot) to get 10mV on 0,22R/5W, this will be 50mA per fet.
Regards

 

[mathez]

ok.thank,by the way,the hum/noise too much?
this my pictures

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[apexaudio]

ok.thank,by the way,the hum/noise too much?
this my pictures

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

'Coolet' pcb design, look nice. Amp is very quite without hum and noise, use GND wireing as I suggest.
Regards

 

[apexaudio]

Mathez, what transistors you use instead BF420/BF421?
Regards

 

[mathez]

Mathez, what transistors you use instead BF420/BF421?

i use mpsa92/42,may be it's wrong replacement?

 

[apexaudio]

i use mpsa92/42,may be it's wrong replacement?

MPSA42/92 is ok for replacement, but I prefer BFs.