Pedja Rogic JFET or Nelson Pass B1?

[regiregi22]

Hi folks!

That's the first time I write on this forum, but I've been following it since more than a year, having actually built a CMoy, a PPAv2, an unregulated and a regulated LM3886 based chipamps...

So i was wondering about my next project, a discrete preamp. Just for the fun of it, I've discarded using OPAMPs. I don't really need gain, so a buffer is OK. But there will be no problem in having some of it.

After researching all I could, I've came to two of them: Pedga Rogic JFET buffer and Nelson Pass B1 buffer. I've seen that both are well documented, and well regarded among audio DIY.

So my question is, wich one should I try to build? Any other one I've missed?

Thanks for all,
keep the solder flowing!

 

[regiregi22]

I've just seen that there is a GB for a DC coupled version, if i get hurry i can get one from the next batch

 

[Gordy]

I would suggest to start with the B1; the documented performance is good and help is easily available on this forum in the Pass section.

Then, after you have it working well, you can build the Rogic buffer and compare the two!

 

[Joachim Gerhard]

I have build the B1 direct coupled with LSK389C and the sound is very transparent, as if it whould not be in the system. I got a frequency response to 6.5MHz -3dB and very low noise and distortion. I used two Alps 10kOhm K Faders, so i can adjust the balance. The faders reduced the frequency response to 2.5MHz -3dB worst case because the output impedance interacts with the fets input capacitance. With a 100kOhm TKD pot the sound was worse. Less extemded and open, so i whould not recommend a high impedance pot.