whomever send these to OPLDF , I promise to further optimize it
(in a decade or two)
(in a decade or two) Zen, it took less time to get ready to go to the moon, and that was back in the 1960's when we were not far from stone knives and bearskins.
Hey
Well, while gathering parts, I "sit" and try to understand the hole circuit 😉
If one have to use ZM DC-servo suggestion/sim, one have to apply another psu, with 24vdc regulated ? or ? (See BAFxxx.pdf)
I will try to use some IRF250 in this circuit, hoping to end up with around 100watt pro channel (approximatly half the original circuit) -I like it around 100w, as i know my heatsinks can handle that.
I will try to figure out, which voltage/bias combination will fit my IRF250's.
Anyway, i don't understand why nobody really succeded in making this circuit work with a normal regulated psu ? - Anybody care to try to explain why ?
Rgds; Jesper.
Well, while gathering parts, I "sit" and try to understand the hole circuit 😉
If one have to use ZM DC-servo suggestion/sim, one have to apply another psu, with 24vdc regulated ? or ? (See BAFxxx.pdf)
I will try to use some IRF250 in this circuit, hoping to end up with around 100watt pro channel (approximatly half the original circuit) -I like it around 100w, as i know my heatsinks can handle that.
I will try to figure out, which voltage/bias combination will fit my IRF250's.
Anyway, i don't understand why nobody really succeded in making this circuit work with a normal regulated psu ? - Anybody care to try to explain why ?
Rgds; Jesper.
All Burning Amp Festival Mr Pass talks is documented by writen article
with all topology refinements , schematics updates and build councils.
After Vfet Draft 2 article i can back to build CSX1 and Vfet DiyP2 because all circuit aspect is verified
that for me the best moment to start completed components and finaly diy amplifiers.
I BAF coverage thread Papa write us about 2SK77B and probably Schade Feedback 50W article is in preparation
http://www.diyaudio.com/forums/pass-labs/280950-baf-2015-coverage-81.html#post4736375
Wind, sky and clouds
autumn is comming
let's run hot class A 🙂
BAF 2016
Matthieu Boré - Ring of fire
http://www.diyaudio.com/forums/club...firstwatt-vfet-sit-amp-2-a-3.html#post4840723
with all topology refinements , schematics updates and build councils.
After Vfet Draft 2 article i can back to build CSX1 and Vfet DiyP2 because all circuit aspect is verified
that for me the best moment to start completed components and finaly diy amplifiers.
I BAF coverage thread Papa write us about 2SK77B and probably Schade Feedback 50W article is in preparation
http://www.diyaudio.com/forums/pass-labs/280950-baf-2015-coverage-81.html#post4736375
Wind, sky and clouds
autumn is comming
let's run hot class A 🙂
BAF 2016Matthieu Boré - Ring of fire
http://www.diyaudio.com/forums/club...firstwatt-vfet-sit-amp-2-a-3.html#post4840723
Last edited:
I hope you have heard the original with Johnny Cash. It is available on YouTube.
Johny Cash is most delicious version 😀
Thanks Grimberg very enjoyable music.
I imagine play one day this song on Schade 50
let's dream
Thanks Grimberg very enjoyable music.
I imagine play one day this song on Schade 50
let's dream
Of course. Note a couple things:
1) The amplifier must be driven by something with a resistive component
to its output impedance. That means that the source cannot be capacitively
coupled, or if it is, there is a resistor to ground after it. Otherwise the
amplifier will motor-boat.
2) The DC Drain voltage of the circuit's gain transistor is temperature
dependent, but it generally should be fairly stable if the heat sinking is
adequate - If it's not stable enough you can put a 5 or 10 watt 220 ohm
resistor from Drain to Source to stabilize it better. I don't think you need
the complexity of a servo.
😎
If your source is cap coupled, then you will need some resistance to ground.
Try a value like 10K and watch for motorboat (with load). Decrease the
resistance until the motor stops.
😎
I am interested in this circuit. How did you go about making the 6.15V. Do you have a schematic of the 6.15V circuit? Does this circuit invert the signal? I have not followed this thread too much not needing all the power this build makes.
Attachments
Motorboating would possibly have happened despite the servo.
The servo idea was a reaction on the the running away of the bias some people described.
Small variations in the gate biasing voltage produced big jumps in the drain current.
The servo was thought to be faster than the hand turning the trim pot
...😀😀😀
The servo idea was a reaction on the the running away of the bias some people described.
Small variations in the gate biasing voltage produced big jumps in the drain current.
The servo was thought to be faster than the hand turning the trim pot
...😀😀😀
Schade 50 have ready 20dB of gain by it self i was think we can play him with passive pre or maybe try autoformer volume control.
Do we need front end stage for hockey puck ?
Sit / Vfet pre amp for example Luminaria ?
My research is to preserve transparency and natural sound timbre quality.
Minimal count of components in audio chain with maximal enjoyable music
Attachments
Last edited:
When building a scaled down version of this circuit using IRFP250 what voltage would you use? I have no need for 50 watts but I am very much interested in building a scaled down version. Has anyone actually built this circuit using the IRFP250 or some other mosfet?