Pass "DeLite" Amp from BAF

[stefanobilliani]

Originally Posted by Puffin

I used the IXTH6N50DN for these boards. I will re-build them and see what happens. I also have some IXTH20N50 chips and may make up some boards for those as well.

I wil report back in due course.

Rob.

I 've used mainly IXtH6N50D2 , and later the Power Jfet

[vdi_nenna]

Been following along on this thread and see that a CCS version of a simple 085 jfet amp has been built. Is the most recent schematic on page 61?

Haven't finished the Z9 yet and dying to build this one!

Thx,

Vin

[stefanobilliani]

Originally Posted by vdi_nenna

Been following along on this thread and see that a CCS version of a simple 085 jfet amp has been built. Is the most recent schematic on page 61?

Haven't finished the Z9 yet and dying to build this one!

Thx,

Vin

The most recent schematic with R085 is here : Pass "DeLite" Amp from BAFBut I have
a new one , mainly becouse of the way the negative voltage has been apply from the original power supply, thank you Mr Pass for the ciruit . With lightbulb , with ccs of page 61 , or also a ccs with fixed current ( to be tested more ) where the -V at the gate decide just the Voltage operation of the circuit ( typical half -the rail ) and the current through the Jfet remains the same .

[stefanobilliani]

Here it is , that is how I built it , for the ligth bulb version there are obviously some modifications in the Power Supply .

I left to the current source to be drawn since there are various permutations for it .

Enjoy .

s

[Tea-Bag]

Cool, I am dumb - this version allows you to tap off the PS to get a negative voltage I presume, without another bench supply?

What have you settled on roughly for negative gate supply voltage?

[buzzforb]

Originally Posted by Nelson Pass

You can rig a "negative supply generator" off of your existing transformer.

Here's one.

Tea-Bag, Nelson posted this in one of my threads. It may help as well.

[stefanobilliani]

Originally Posted by Tea-Bag

Cool, I am dumb - this version allows you to tap off the PS to get a negative voltage I presume, without another bench supply?

What have you settled on roughly for negative gate supply voltage?

Yes it does that .
The negative gate voltages varies , depending on the current source implementation , the voltages of VDD , and the current throug the Jfet .
Now with fixed CCS of 1,4 amps for example , VDD = 30 , Drain of the Jfet at 16 volts , the gate to ground voltage is - 3,5 volt

[stefanobilliani]

Originally Posted by buzzforb

Tea-Bag, Nelson posted this in one of my threads. It may help as well.

yes , that is . Thanks again for the help :-)

[vdi_nenna]

The negative gate voltages varies , depending on the current source implementation , the voltages of VDD , and the current throug the Jfet .
Now with fixed CCS of 1,4 amps for example , VDD = 30 , Drain of the Jfet at 16 volts , the gate to ground voltage is - 3,5 volt

As Mr Burns would say, "Excellent!"

BTW- The negative supply doesn't need to be high current, correct? It only needs to be a fraction of the Drain current, yes, no, maybe so?


Vin

[stefanobilliani]

Originally Posted by vdi_nenna

As Mr Burns would say, "Excellent!"

BTW- The negative supply doesn't need to be high current, correct? It only needs to be a fraction of the Drain current, yes, no, maybe so?


Vin

Little current , 1,3 mA