I think power is not critical as an improvement to the F2, as it is intended to be used with very high efficiency drivers.
My bet will be
1. A more rigid current source? ...or
2. Improve the linearity of the transconductance
My bet will be
1. A more rigid current source? ...or
2. Improve the linearity of the transconductance
I am not sure if this will be a better current source compared to the MOSFET. The F2 runs at 2.5A, so even if you drop 30V across your resistor, it will be only be 12 Ohm - hardly a huge resistance to be called "Rigid". Further increases in the line voltage can bring up the resistance slightly, but the heat dissipation will not be practical.MEGA-amp said:
Nelson Pass said:
Mmmmm...is it already submitted to AudioXpress? ( so we could see it here sooner rather than later )
🙂 😉
MEGA-amp said:
Look here:
http://www.diyaudio.com/forums/showthread.php?postid=1145318#post1145318
If you are using 110 v bulbs , then use roughly four time less wattage bulbs for the same current. Or, in other words, use a couple of 300w 110v bulbs, just like in Zen lite...
Vix said:
I have one here, but I haven't written it up. It has about 1/5 the
distortion of the original.
😎
Nelson Pass said:
😎
Hi,
Could you please share some breadcrumbs before the meal arrives..?🙂
For example,
Is it a fully Mosfet design, or incorporates a j-fet?
Is it single-ended or balanced?
What is the current/voltage through CCS?
Thanks...
Can't wait for it...
😎
Re: Filip's F2
Hi everyone!
Here are the values of my eq network
C=15u, R=8,2 Ohms in parallel with R=62 Ohms... in parallel with the drivers. Just FYI 🙂.
The setup is indeed very DIY 🙂, but there is no hum, buzz or anything at all, and the amp is very silent... unlike my phono preamp (VSPS) 🙁.
I am eagerly waiting for the next F2 edition as well, will definitely build it.
Regards,
Filip
Hi everyone!
Here are the values of my eq network
C=15u, R=8,2 Ohms in parallel with R=62 Ohms... in parallel with the drivers. Just FYI 🙂.
The setup is indeed very DIY 🙂, but there is no hum, buzz or anything at all, and the amp is very silent... unlike my phono preamp (VSPS) 🙁.
I am eagerly waiting for the next F2 edition as well, will definitely build it.
Regards,
Filip
toufu said:
By the way, If you build F2 lite, or decide to use a resistor as a current source, it is then possible to use 48 V supply. Burn 2/3 across the resistor and 1/3 across the mosfet 🙂
Nelson Pass said:
Only 1/5 the distortion??? Isn't the distortion responsible for giving it that 'tube like' charm ?
That's a good question. I don't mind a little 2nd harmonic, but I
have always thought that a little less in the F2 would be a good thing.
Of course improving it means either getting a better FET or making
a more complex circuit. The better FET idea is very appealing.
I think I have some curves at home that will illustrate this, and I'll
see if I can dig them up tonight.
😎
have always thought that a little less in the F2 would be a good thing.
Of course improving it means either getting a better FET or making
a more complex circuit. The better FET idea is very appealing.
I think I have some curves at home that will illustrate this, and I'll
see if I can dig them up tonight.
😎
Nelson Pass said:
Any chance to look at a more rigid CCS, certainly a more complex circuit, but will the performance gain offset the extra effort?
It turns out that the current sources, whether ccs, srpp variants,
or Alephs, are not the source of much distortion at all. You could
say that they are already pretty stiff compared to the rest of the
circuit.
Your performance improvements must come from the gain device itself.
😎
or Alephs, are not the source of much distortion at all. You could
say that they are already pretty stiff compared to the rest of the
circuit.
Your performance improvements must come from the gain device itself.
😎
