120 Volt psu PreAmp - lowest possible G-FeedBack

Status
Not open for further replies.
120 Volt may become 150 or even 300 Volt supply!

.
hi.
The 120 Volt version has got great, in my opinion, simulated test data.
Not much more to wish for, on my behalf.
🙂
(see my posted test diagrams for details)

Now.
I have one idea to take it one step further.
To get more into the Tube PreAmp division when comes to voltage supply.

So thinking is 200 or maybe 300 Volt DC supply.
I do not things will get worse .. only better at higher volt output.
Say output levels like 😎 30 Volt RMS.
And Gv = 31 ( +30 dB )
-----------------------

1. One big change will be input and second stage Transistors.
2SC2240/2SA970 has to be replaced with 300 Volt devices!!!
Also has got to decide for what output stage 300 Volt devices to use.

2. Will have to rework my discrete Voltage regulator ...
to work good at 300 VDC and like 100 mA Class A OUTPUT.

3. At Lineup Audio discussion forum I will consult my assistant audio people
to get the best ideas for this ambitious
Low FeedBack High 'Tube' Voltage project.
------------------------------


I will do a lot of good work for you all. Up here in north of Sweden.
And Be back later this Autumn/Winter
Lineup 😉

Until then, enjoy this beautiful Sweden Autumn landscape view
 

Attachments

  • sweden_autumn.jpg
    sweden_autumn.jpg
    88.4 KB · Views: 189
Hello.

The 120 Volt version has got great, in my opinion, simulated test data.
I have one idea to take it one step further. To get more into the Tube PreAmp division when comes to voltage supply.

So thinking is 200 or maybe 300 Volt DC supply. I do not things will get worse .. only better at higher volt output. Say output levels like 😎 30 Volt RMS.
And Gv = 31 ( +30 dB )
-----------------------

A. Will have to rework my discrete Voltage regulator ...
to work good at 300 VDC and like 100 mA Class A OUTPUT.
B. At Lineup Audio discussion forum I will consult my assistant audio people to get the best ideas for this ambitious Low FeedBack High 'Tube' Voltage project.

any comments
any helpful ideas .. the high voltage regulator ..
any thing else you want to ask


lineup
 
thanks
you are so friendly & nice

below you have diagram of my conceptual idea
for this new 300 volt supply pre amplifier
this is the starting point i will start my work from

please every body, i do not want any one else here around
start making such an audio pre amplifier
because this will be my one of my unique projects
and the more unique the better 😉

Lineup audio projects web site
 

Attachments

  • 300volt_preamp.png
    300volt_preamp.png
    59.5 KB · Views: 200
lineup said:
For output current amplifier I can think of using something like IRF9610 if can take 300 Volt, that is

I have found my high voltage lower power suitable P-MOSFET.
IRFR9310
Has got only 270 pF input capacitance.
RDSon ~ 5 ohm (max 7)
Max Voltage -400 Volt
PDF (Vishay) http://www.vishay.com/docs/90357/90357irf.pdf

Enjoy 😎 😎 !!!
Lineup
-------------------------------------------
-------------------------------------------
-------------------------------------------
IRFR9310
Advanced Process Technology. Fully Avalanche Rated.

Third Generation HEXFETs from International Rectifier
utilize advanced processing techniques to achieve
low on-resistance per silicon area. This benefit,
combined with the fast switching speed and ruggedized
device design that HEXFET Power MOSFETs are well
known for, provides the designer with an extremely
efficient and reliable device for use in a wide variety of
applications.
 
300 Volt psu Pre Amplifier

!!!!! first setup

Gain = x20

2nd order distortion, as low as -80.6 dB
Into 2 kOhm load 😎 Output cap = 100 uF electrolytic

all other harmonics well below -110 dB
absolutely no global feedback !!!

wooooowwww :att'n: :att'n: I made it great!
A very good 300 Volt amplifier
 
homemodder said:
Nice lineup,

Similar to something i am using as preamp except 1 less tranny,
the cfp with the mosfet is my vas and buffer, one less stage.
Kinda like Aleph, just 2 stages. Sounds pretty good.

homemodder

such amplifiers, with minimal number of active transistors can be very good
epecially in case we need not so much voltage gain

this is well in line with Nelson Pass article: [PDF] Audio, Distortion and Feedback

Global negative feedback and ..
Few stages = lower order harmonics dist 😎
More stages = more complex higher order harmonics dist spectra



Regards
Lineup
 
Status
Not open for further replies.