Thanks Juan Antonio i am fine after i see your diy work i guess you are fine too
Yes i agree if simple jfet buffer give you satisfaction keep it !
Some very apreciated by audiophiles 300B SET's amplifiers have pentode tubes drivers some others are all triodes
i was curious if new all vfet's signal path are possible today.
Remember Papa speak with passion and entusiasm about Yamaha B-1:
https://www.youtube.com/watch?v=cyfdm4zsPx0
My hats off for Dady great amigo 😀
Thanks the effort is for Juan Antonio, thanks to Michael..
Only by casual beibi. There are no merit in this.
Finally the 2SK180D was much better than THF, You have several of this acquisition lot with jama and me. Expensive but reliable.
Now I am in the middle of an Ongaku clone ( 89%construction stage) an CSX1 with parallel group of very close matched Vfets. (The dc current in the out is 0.02volts and the gate voltages are one branch 9.06volt and the other -8.89volt, but is on the bench for see what happen with response. Then I will try a monster like Michael and Juan Antonio at least they did recently.
The best for you Christophe and the rest of Knights of this, but Square, table.
And special regards to the mentor of us the Guru NP.
Finally the 2SK180D was much better than THF, You have several of this acquisition lot with jama and me. Expensive but reliable.
Now I am in the middle of an Ongaku clone ( 89%construction stage) an CSX1 with parallel group of very close matched Vfets. (The dc current in the out is 0.02volts and the gate voltages are one branch 9.06volt and the other -8.89volt, but is on the bench for see what happen with response. Then I will try a monster like Michael and Juan Antonio at least they did recently.
The best for you Christophe and the rest of Knights of this, but Square, table.
And special regards to the mentor of us the Guru NP.
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Set up Gerd's circuit (post 564) and below
With R2 = .33 ohms and R4=.5 ohms
R8 and R10 replaced by 5k pot
Using variac and setting Voltage at D1 = 50V I get
Voltage at D2 = 25V by adjusting 5k pot
drop across R2 = .55V
drop across R4= .78
so Current =1.6A
Voltage at C2 = 1.5V
If raise Voltage at D1 to 57V (my max) , adjust D2 to 28V and current rises slightly above 1.6A. I turned it off after a couple of minutes.
Next I plan to change R2 to .25 ohms and R4 to .33 ohms and see what current I get.
Then I'll wire up another channel and have a listen
With R2 = .33 ohms and R4=.5 ohms
R8 and R10 replaced by 5k pot
Using variac and setting Voltage at D1 = 50V I get
Voltage at D2 = 25V by adjusting 5k pot
drop across R2 = .55V
drop across R4= .78
so Current =1.6A
Voltage at C2 = 1.5V
If raise Voltage at D1 to 57V (my max) , adjust D2 to 28V and current rises slightly above 1.6A. I turned it off after a couple of minutes.
Next I plan to change R2 to .25 ohms and R4 to .33 ohms and see what current I get.
Then I'll wire up another channel and have a listen
Attachments
For me that would depend on how many R100s I had left.
If I only had 2 to 4 left probably 35W to 40W.
If I had 20 left maybe 50W to 60W.
How fearless are you?
🙂
Not to worry.
1.5A to 1.6A is a perfectly nice bias point for a 46V to 50V powersupply.
Put some music through it I'm sure it will sound very nice.
Stack of IXFN devices arrived.
Started measuring Vgs threshold, this is what I got for 10 devices:
4.00V
4.06V
4.06V
4.10V
4.10V
3.96V
4.02V
4.02V
3.98V
4.20V
So mostly hovering around 4.0V.
I'll do some curves of Id vs Vgs at realistic operating conditions/temperature later.
Started measuring Vgs threshold, this is what I got for 10 devices:
4.00V
4.06V
4.06V
4.10V
4.10V
3.96V
4.02V
4.02V
3.98V
4.20V
So mostly hovering around 4.0V.
I'll do some curves of Id vs Vgs at realistic operating conditions/temperature later.
I don't have all the parts yet.
Just want to get a feel for these devices first before I step into the gladiator ring and destroy the lion.
dunno
don't have neither greenies to spare (for them ) nor time .... or will
is that curse or luck - not needing more than regular FW wattage frame ........
don't have neither greenies to spare (for them ) nor time .... or will
is that curse or luck - not needing more than regular FW wattage frame ........
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