F4 power amplifier

[generg]

buzzforb,

what do you mean by this...?

"You will see greater seperation in their response from signal chnages, but this can be minimized by paralleling devices."

[buzzforb]

Just because they match up in terms of Vgs vs Id, does not mean that they have similar Yfs, so they will respond differently to an incoming signal. The datasheets show the 240 as having a Yfs of 7S and the 9240 having Y(g)fs of 4.2S. If a 1V sine wave is applied to both, you will get different responses. In truth, they are close enough that it is no big deal, as most music happens at very low power levels, but on more dramatic passages, with higher transients, you will have greater seperation, as the N channel part is able to provide more current for a given volt than the P channel part.

[generg]

Thank you, yes I saw the different Y and the different Ciss and so on.

But what is the different Vgs of normally over one Volt doing? Distorsion? Or is it not important in class A.

Maybe Iwill look at a book......

[buzzforb]

As Nelson says, "it tends to favor the postive going waveform", a little second harmonic.

[generg]

Thanks buzzforb!

[flocchini]

Originally Posted by Zen Mod

two things , unfortunately :

1. I'm not Pa

2. yes , with Jensen , being xformer sans CT secondary , you must use one per leg

3. looking at schm you posted in #3390 , connection is like attached :

4. #3 and #4 are just to confuse you , considering two things mentioned

I really like the balanced headphone amp I built. I am thinking about building a SE unit for another system.

As generg pointed out matched irf240/irf9240 are available. As an experimentI could try a pair of these or stick with the 510/9510s . Have both

I would use the Jensen JT-123-Flpch (purchased 4) mentioned in the F6 thread instead of the Jensen JT-123-ALCF (no longer available)

Are C1 and C2 in the original HP circuit there to block DC. Are they necessary if a transformer is used

Thanks

[Zen Mod]

you must point me to "original HP circuit"

[flocchini]

Originally Posted by Zen Mod

you must point me to "original HP circuit"

it appears in post 3390 and in 3026

thanks

[Zen Mod]

Originally Posted by flocchini

.......

Are C1 and C2 in the original HP circuit there to block DC. Are they necessary if a transformer is used

Thanks

Originally Posted by flocchini

it appears in post 3390 and in 3026

thanks

yes, they are still necessary

where you are going to insert xformer , exactly ?

[flocchini]

I used the schematic in 3399

Thanks