Good evening!
Since I´m soon to be finished with my X-Son of Zen I need a good preamp that converts the unbalanced signal from my CDP to a balanced one which is capable of driving an horribly low input impedance (470 ohms!).
For various reasons I don´t want to build a BZLS, so I´m looking into tube/hybrid territory instead.
To get straight to my question: Does LPT´s work good with low µ triodes like 12B4A?
I´m thinking 6k8 or so on the plates, CCS in the tail and Mosfet buffers on the outputs.
Would I be better of with higher µ triodes and some feedback to get the gain down?
I like the 12B4A very much and I happen to have a good number of them (quality brands) but I´m a little hesitant since I believe I´ve read somewhere that LPT´s works best with high µ triodes.
Best regards,
Daniel
Since I´m soon to be finished with my X-Son of Zen I need a good preamp that converts the unbalanced signal from my CDP to a balanced one which is capable of driving an horribly low input impedance (470 ohms!).
For various reasons I don´t want to build a BZLS, so I´m looking into tube/hybrid territory instead.
To get straight to my question: Does LPT´s work good with low µ triodes like 12B4A?
I´m thinking 6k8 or so on the plates, CCS in the tail and Mosfet buffers on the outputs.
Would I be better of with higher µ triodes and some feedback to get the gain down?
I like the 12B4A very much and I happen to have a good number of them (quality brands) but I´m a little hesitant since I believe I´ve read somewhere that LPT´s works best with high µ triodes.
Best regards,
Daniel
Fuling said:Good evening!
Since I´m soon to be finished with my X-Son of Zen I need a good preamp that converts the unbalanced signal from my CDP to a balanced one which is capable of driving an horribly low input impedance (470 ohms!).
For various reasons I don´t want to build a BZLS, so I´m looking into tube/hybrid territory instead.
To get straight to my question: Does LPT´s work good with low µ triodes like 12B4A?
I´m thinking 6k8 or so on the plates, CCS in the tail and Mosfet buffers on the outputs.
Would I be better of with higher µ triodes and some feedback to get the gain down?
I like the 12B4A very much and I happen to have a good number of them (quality brands) but I´m a little hesitant since I believe I´ve read somewhere that LPT´s works best with high µ triodes.
Best regards,
Daniel
since you want to use CCS in tail,I don't see why you can't use 12B4 in LPT............
in that configuration length of tail is always critical........and with CCS your is biggest

I´m thinking the same way, with a CCS in the tail the "balancing act" shouldn´t suffer due to the lack of µ.
I guess building a breadboard is the best way to find out!
I guess building a breadboard is the best way to find out!
Fuling said:but I´m a little hesitant since I believe I´ve read somewhere that LPT´s works best with high µ triodes.
That's because the common mode noise rejection increases with increasing mu.
Fuling said:
I feel stupid, I don´t have a clue what that means...![]()
you know me -I mean everything

I mean everything
Well, I´m still not getting any wiser

But after all it seems that I´ve had my original question answered, thanks!
Fuling said:
Well, I´m still not getting any wiser![]()
But after all it seems that I´ve had my original question answered, thanks!
http://www.google.com/url?sa=t&ct=r...Mwkri3DDUIfFlkVI=&sig2=BIL6TzL06q2Wmpk36anY2Q
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