Was this setup ever tested or simulated?
It should be a killer amplifier?
Mosfet buffer output
No negative feedback
Jfet imput gain stage
Maybe slightly low damping factor
Kind of a Ba3 preamp on steroids?
Last edited:
Yes, it was prototyped and tested as proof of concept, but it's far from final version - that one is not recommended to build
Not recommended because it doesn't sound nice?
Is there a final version of this Amp with laterals PP buffer?
Is there a final version of this Amp with laterals PP buffer?
Ofset is not stable as it is?
But maybe cap coupled output could be usable?
Hope to see updates soon 😀
But maybe cap coupled output could be usable?
Hope to see updates soon 😀
Found your schema of post 118 with bjt and one on post
354
What performs better as CSS for the jfet input? The 1k 2w resistor?
The k309 jfet CCS or the one with LM317?
In general LM317 is not advised in audio circuits but maybe in this aplication it is good?
354
What performs better as CSS for the jfet input? The 1k 2w resistor?
The k309 jfet CCS or the one with LM317?
In general LM317 is not advised in audio circuits but maybe in this aplication it is good?
I don't know why it has to be avoided or not depending on the usage.
Maybe at low current it is fine but not at higher current?
Maybe you can enlight me?
Maybe at low current it is fine but not at higher current?
Maybe you can enlight me?
IME the LM317 makes a nice CCS - there was even a paper from Walt Jung about it.
Find it, read it, test it - or believe anything anyone writes on the internet...
just for the record:
Find it, read it, test it - or believe anything anyone writes on the internet...
just for the record:
Attachments
Last edited:
I am here to learn, will read the paper about the 317
It is difficult to distinguish between ral and fake info in the net.
Will give a try to the 317 ccs being temperature stable do avoid ofset drift.
Thanks a lot for all your advice
It is difficult to distinguish between ral and fake info in the net.
Will give a try to the 317 ccs being temperature stable do avoid ofset drift.
Thanks a lot for all your advice
Hi Juma I need some info about 2 preamps you designed
firs is one of the first BJT version of the LSK pre, as I understood it is a cascode
LSK pre - BAF 2013
the second is a version in preamp ideas for F5 tread post 53
Preamp ideas for F5
it is similar, with negative feedback but output BJTs are not cascoding? they are amplifying? it is more like an F5?
Does the first have lower output impedance?
Which one sounds best?
firs is one of the first BJT version of the LSK pre, as I understood it is a cascode
LSK pre - BAF 2013
the second is a version in preamp ideas for F5 tread post 53
Preamp ideas for F5
it is similar, with negative feedback but output BJTs are not cascoding? they are amplifying? it is more like an F5?
Does the first have lower output impedance?
Which one sounds best?
Last edited:
I really would like to avoid the complexity of #485 because of various reasons (time, transistor matching etc)
Therefore I would like to stay on the 4 transistor configuration, maybe just adding the LM317 or JFET CCS on the input stage.
Would you then advise to use the first or second topology I just posted?
Therefore I would like to stay on the 4 transistor configuration, maybe just adding the LM317 or JFET CCS on the input stage.
Would you then advise to use the first or second topology I just posted?
since I mixed the links you mean the second schema the one without PSU regulators, the original LSK preamp with BJT output
