F4 power amplifier

I am surprised that his pricing is that good. He has to be pulling from the extremes. I have purchased from him before, in bulk, and he is indeed good to deal with. You will see greater seperation in their response from signal chnages, but this can be minimized by paralleling devices. Excellent info, Generg.
 
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.
 
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 :devily:

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