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
The most recent schematic with R085 is here : http://www.diyaudio.com/forums/pass-labs/153832-pass-delite-amp-baf-67.html#post2619650But I haveBeen 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
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 .
New Schematic with R085 Power Jfet
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
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
Attachments
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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.
Attachments
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
Tea-Bag, Nelson posted this in one of my threads. It may help as well.
yes , that is . Thanks again for the help
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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
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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
Stefanobilini and All,
It's been discussed elsewhere that the IRFP9240 can cause distortion or is a bad choice for a CCS mosfet? Is this a concern in this design? Would a Fairchild P channel mosfet be a better choice?
http://www.diyaudio.com/forums/pass-labs/121228-f5-power-amplifier-887.html#post2300838
Mr Pass goes on to say that some people actually pefer the IRF9240 to the Fairchild FET.
It's been discussed elsewhere that the IRFP9240 can cause distortion or is a bad choice for a CCS mosfet? Is this a concern in this design? Would a Fairchild P channel mosfet be a better choice?
http://www.diyaudio.com/forums/pass-labs/121228-f5-power-amplifier-887.html#post2300838
Mr Pass goes on to say that some people actually pefer the IRF9240 to the Fairchild FET.
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But I don't think Nelson is discussing it's use as a ccs. The F5 does not have a CCS.
That's correct . For a current source the IRFP9240 should be pretty good , and afaik it is the device implemented for the F2 current source ( but also F1 ) . Actually that is the current source arrangement I am listening from a week or so , and imo it is ok .
For a current source the IRFP9240 should be pretty good
That's great, because I have lots of them!
That's great, because I have lots of them!
By the way I am using Fairchild here .
Got the 085s from Tea-bag the other day. Great price, nicely packed and quick delivery!
Thanks Tea-bag! Looking forward to using them soon on the Delite-CCS!
Vince
Just finished to set up one channel with the SJEP120R100 from the previous schematic with just one more resistor . Works well and good sound also .
I am just wondering what a marvelleous amp will this come with feedback and also the aleph current source
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