new GAN amplifier

Of course there are different drive conditions and they are all addressable in changing over mosfets to bjt, you just choose not to believe it. 🤦‍♂️ 

And I'll post once again the pro's for going bi-polar

"BJTs tend to have better, more linear gain characteristics…and can give you a lot higher voltage gain than MOSFETs.…They're also able to handle higher output currents…and have a lower output impedance.…That gives BJTs a huge advantage over MOSFETs…for building amplifier circuits…that need to provide a significant amount of output power…and or drive loads that have low input impedance.…MOSFETs are going to have a harder time…driving a low impedance load…because they have a higher output impedance.…"

 

You can't just swap out the output FETs for the BJTs. There are a lot of other things that need to be addressed. It is not the same amplifier any more.


Again, do you know how to design amplifiers? I get the impression no or your replies would be more technical. Hence what you are posting is mainly heresay.

You can’t just swap out the output FETs for the BJTs

Please don’t say I said this sunshine, because I didn’t.
I said there’s a member who converts Mosfet amps into a BJT amps, and of course there’s more to it than just changing the output devices only a fool would think or suggest otherwise.

You can do it, if you had any half decent tech knowledge you would understand, end of story.

This is what you said "sunshine" and to my point, you are essentially making a different amp.  The one who doesn't have any decent tech knowledge is you. I have designed many amplifiers, discreet and on integrated circuits, hence why what you post sounds so ridiculous to me. You can't simply change an output stage on a power stage between MOSFET and BJT. It don't work that way sunshine.   Now if you had any tech knowledge you would know:

• Typical output stages have 0 voltage gain so quoting in this case that they have higher voltage gain is silly.
• In an amplifier, output current is mainly a function of thermal limitations. I can cheaply buy a 100A MOSFET, more than enough for almost any power level so to say a BJT can handle higher current is just wrong. That has not been true for decades.
• Output impedance is a function of device and circuit, not just the device so making a claim a BJT has lower output impedance is specious. You can try to make the claim there is less difference in base/emitter voltage compared to gate/drain voltage over loading, but higher biasing of the output stage with modern FETs can negate that advantage. As well a BJT requires a very high current to drive it and that current gain is variable w.r.t. output current leading to distortion inducing mechanisms elsewhere in the amplifier that a FET amp may not experience ..... And also why you cannot simply swap the output stage! ...and have it work properly.

Actual "tech", not a cut and paste tech ....

There’s a post a member put up a couple of weeks ago (go find it), who does mods for his customers, where he takes a Mosfet amp removes the complimentary N/P channel Mosfet output stage and replaces it with complimentary NPN/PNP Bi-Polar (BJT), and he and his customers say it all in their description of the sound change.

IMHO, Gfi is making a lot of sense here

Still awaiting my Voyager (GaN), but still loving my EVS 1200 (class D)