BF862 Preamp

Hi Juma,

for the psu, would irfp240 work in place of the irf044? looks like the irf044 has become obsolete here in the states, well at least mouser and digikey.

from the original threads, this pre has a gain of 2 and specifically designed for the F5. Do values need to be changed to use with other amps or should be fine.

btw, how do you like the BF862 sound vs. the dual 2sk170/sj74 pre that you originally built for the F5? the sk170/sj74 has a higher gain of 10dB?

been wanting to try out your preamp designs, not using an F5 though.

thanks!
 
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PSU voltage changes

Hi!

I'm glad I found this thread as I'm currently trying to find a good line amp after the DAC I'm working on. I read several articles from Erno Borbely's all fet line amps and buffers, however, I like the simplicity of JBoz like SE amps.

I would like to try this nice preamp but I want to use 2SK170V or LSK170C. I did some silmulation using spice models of LSK170C and found that for my needs I have to modify the PSU voltages and Rs and Rd values.

For 2V RMS out and ~0.08% THD I need +36V for the positive and -1V to -1.2V from the negative source (with Rs 75 and Rd 1k8).

Is it enough to modify the zenners to get these voltages?
Can the negative regulator provide such low voltages as -1 to -1.5 volts?

Thanks!
Zsolt