You can easily build a balanced F5 with dual diff pairs.
Who wants the glory of posting the schematic?
😎
Like this?
Attachments
Attachments
That's one. I can think of a couple others...
😎
seems that there is more than few ways to skin a ... UGS .....

That's one. I can think of a couple others...
😎
I wonder this one will be better or not ?
Attachments
Hi umut1001,
Using 15R instead of 10R will reduce the Idss (see fig 4B, page 28 of Borbelly Part 1) of the jFET.
hi..I matched my jfets and there are high IDSS ones.12ma.Maybe i can use them.
Also i am waiting for a good bridged circuit
hi..I matched my jfets and there are high IDSS ones.12ma.Maybe i can use them.
Also i am waiting for a good bridged circuit
Save your high Idss jfets for a long tail differential inputs (Aleph J) and use 6 or 7mA BL jfets or even highish GR rated ones. The F5 jfets are set for about 4mA or less.
I wonder this one will be better or not ?
interesting ; I admire lateral thinking 😉
but - I'm not sure in amount of benefit
Wensan,
why not to keep the 2 ways NFB?
I have been thinking since the beginning that was an interesting particularity of the F5.
why not to keep the 2 ways NFB?
I have been thinking since the beginning that was an interesting particularity of the F5.
Wensan,
why not to keep the 2 ways NFB?
I have been thinking since the beginning that was an interesting particularity of the F5.
in this case - you can't , because of need to implement inverting topology .
that's SUSY bridged F5
I am the champion for asking stupid questions.
May be another one:
Is the schematic ( post 6620) for a symetrical input only, working or not?
May be another one:
Is the schematic ( post 6620) for a symetrical input only, working or not?
Last edited:
Dual mono, not monoblock - twin 440VA transformers, 80,000uF per channel, nothing else changed from references.
Shared power cord, no chassis.
Shared power cord, no chassis.
Wensan,
why not to keep the 2 ways NFB?
I have been thinking since the beginning that was an interesting particularity of the F5.
The 2 ways NFB will interfere with the differential structure.
The input signals counteract each other.I am not certain.
No signal will be amplified.
I don't think it will work.
The input signals counteract each other.
No signal will be amplified.
I don't think it will work.
Oh! I am wrong.
Most of signal will be amplified without feedback control.
like with every other known gain stage .
besides - even plain vanilla F5 have diff pair at input
not a diff pair... a diff pair is also known as a "long tail pair"... that means a common resistor shared between the emitters or in this case the sources. the input of the F5 does not have this featue.
_-_-bear
Save your high Idss jfets for a long tail differential inputs (Aleph J) and use 6 or 7mA BL jfets or even highish GR rated ones. The F5 jfets are set for about 4mA or less.
I do not have low idss jfet.All of them are above 8ma.Does not them work well ?
- Home
- Amplifiers
- Pass Labs
- F5 power amplifier