B1 Buffer Preamp

no input cap

i didnt understand you..i mean no input cap..i dont like two capacitors on signal path.. is it bad if i short circuit the capacitor? the output cap already filters dc signal so why i use input capacitor?
 

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It simply will not work. Has to be referenced somewhere. With single supply that is half psu. You mix two different things. The symmetrical psus allow no input or output caps. The single ended psu does not. Its either you make the original B1 or the symmetrical supply spin off. Using an output capacitor for the symmetrical one is pure precaution with DC coupled amps like the F5. Using both input and output caps on the original B1 is mandatory.
 
B1-converted D/A-converters?

Lampizator is a CD-player or a DAC modification. The idea is to replace the active op-amp filters and buffers after the D/A-converter with a single-ended triode amplifier stage, thus avoiding numerous transistor stages of the op-amps.

I thought that basically the same could be done with a simple Class A JFET amplifier, possibly using a B1 stage. Because B1 is a voltage follower buffer, it could be developed to a Linkwitz-Riley low-pass filter, like I said in my previous post.

Read this too: http://www.diyaudio.com/forums/tubes-valves/153345-how-lampizator-cd-tube-player-sound.html
 
The B1 buffer is essentially a voltage follower.
A voltage follower is also an essential part of a Linkwitz-Riley filter.
See this: Active Filters

Has anyone tried the B1 voltage follower as a component in a Linkwitz-Riley filter?
This is a perfect application for a B1 type circuit. For LR4, you probably need 3 B1 circuits, one as input buffer and another for every L2 Butterworth stage.

HTH

Doug
 
I agree, it seems like an ideal application for B1. It is on my list of things to do "real soon now".

I don't really know what i'm doing, but in LTSpice I knocked up a pair of Salas's direct-coupled B1-type buffers in 24dB L/R high-pass, and apart from an enormous insertion loss, it performs as I expected. Oh, and with more than 0.015% THD+N @10kHz but I suspect that's due to the sim looking at everything up to 200kHz. I'd really like to build this to test it, as I'm keen on attempting to bi-amp my system. Should I start a thread on it? I haven't managed to find anything really complete on the 'net so far (so far~) about active crossovers without opamps.
 
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...a pair of Salas's direct-coupled B1-type buffers in 24dB L/R high-pass, and apart from an enormous insertion loss, it performs as I expected...

I don't see any reason for this insertion loss. And as far as I remember, there was none in my simulations. I think you did something wrong.

Oh, and with more than 0.015% THD+N @10kHz but I suspect that's due to the sim looking at everything up to 200kHz.

You should not trust the THD+N simulations of spice too much. Just regard it as a tendency.

regards

Flo