Preamp-Buffers - simple idea

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#101
Ok, i will work my way through. I start with this one :
 

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#103
Also one more thing, I usually didn't have good success with cascode on that location.
Would you try to audition the buffer when cascode on both lw and high side is removed?
In my past experience sound should be crispier and more transparent...just my two cents.
 
#104
Maybe the crispness is a pretty kind of distortion.
The zobel is not really necessary but a buffer this powerful may be used to drive long cables, low impedance headphones and such.
I have some listening impressions with the zobel and the input filter shifted to 1.5Mhz.
The sound i get is even a bit smoother and liquid without loosing details and dynamic slam. As far as i can tell this sounds perfect to my ears.
It is very natural but also extremely exiting. It is like riding a Porsche or Maserati full speed on the german autobahn. It is fun but also an intellectual exercise. It is hard to describe but i am listening to music in a fresh way.
 
#105
Joachim Gerhard said:
Maybe the crispness is a pretty kind of distortion.
The zobel is not really necessary but a buffer this powerful may be used to drive long cables, low impedance headphones and such.
I have some listening impressions with the zobel and the input filter shifted to 1.5Mhz.
The sound i get is even a bit smoother and liquid without loosing details and dynamic slam. As far as i can tell this sounds perfect to my ears.
It is very natural but also extremely exiting. It is like riding a Porsche or Maserati full speed on the german autobahn. It is fun but also an intellectual exercise. It is hard to describe but i am listening to music in a fresh way.
Click to expand...

Don't think that the level of distortion with and without cascading could be detectable by the ear however what I think is that one less semiconductor on the signal path could be the reason why the non cascade sounds probably crispier and cleaner.
I have to try this out either way but thank you for sharing your impression here.
 
#106
I will certainly not change the topology. I am too convinced about the result. Try it out yourself. It should work without the cascodes without problem.
Taking about crispness i just heard Ladies of the Canyon again.
Jonis guitar is just there, incredibly detailed, full, frightening dynamic and focussed.
I play the guitar, i told you and this is just awesome.
It even creates a preasure on my chest i only know from life. It is that good.
 
#107
Joachim Gerhard said:
I will certainly not change the topology. I am too convinced about the result. Try it out yourself. It should work without the cascodes without problem.
Taking about crispness i just heard Ladies of the Canyon again.
Jonis guitar is just there, incredibly detailed, full, frightening dynamic and focussed.
I play the guitar, i told you and this is just awesome.
It even creates a preasure on my chest i only know from life. It is that good.
Click to expand...

Pretty interesting.
 
#108
I will build it s soon as I get back to the states and incorporate it on masterpiece if audition will prove to match your impression.
Just FYI, as you know, the j310 will bias the DS junctions of the jfets at around 5-6V.This might not be enough to get good sound out of these devices.
 
#118
I can do that, the buffer has pots on the input. The worst case is then with the pots in the middle position and with a 10kOhm pot that is less then 10kOhm. I could of cause simply use a resistor.
I have measured the buffer though with 15 Ohm loading and that is a real torture test.
I have now reduced the bias resistors to 2/3rd and still the MosFets get extremely warm.
Maybe i need separate gate stoppers or another compensation scheme.
I already like the bipolar version better it is easier to stabilize.
I will post a picture of my build and the current circuit diagram. Maybe somebody has an idea.
 
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