cathode-follower tube preamps..

What are cathode-follower tube preamps? What are some brands that carry these? Their models and price please...

Hi Mara

I was told that i need to get a cathode-follower preamp to match my Pass Labs amp...
all you ned is one with low output impedance such as Sonic frontiers, Manley... look at specs for the ones with bellow 1kOhm, but better if just few hundred ohms.
If you are trying to drive an amp with a low input impedance, and you want tubes then you will need one that has a cathode-follower or Mu-follower output.

However the amp has a balanced input so you might consider tube preamps that are balanced as well. I prefer tube preamps with a direct-coupled output in this case, as they play bass much better with greater extension.
I think you are going to find CF's in most of the tube preamps you go looking
for. It's not the spec I would go looking for.

fwiw, I have 2 Pass amps (30.5 and 100.5's) and I drive them with Conrad
Johnson tube preamps (ART and ACT 2.2) and neither of them have CF's. Their
output impedance "averages" 500 ohms and is not a problem for me. My Pass
amps are rated at 20K or 30k (rca or balanced).

Whatever the input impedance is of your Pass is, just look for a preamp that is
at least 1/10 of that and hopefully a little more because the output impedance
does vary at different frequencies. That spec is just an average.
If you have a direct-coupled output on the preamp the output impedance will not vary with frequency (with most tube preamps its usually the bass where this is an issue).

If you have a 10:1 ratio at 1000Hz but only 5:1 at 20Hz, you will hear that as a loss of bass impact. This is because there will be a slight loss of output voltage in the lower frequencies.
To answer your original question...try Mystere CA11 or CA21 preamps. The CA11 uses a SRPP (Series Regulated Push-Pull) circuit for high gain, low distortion and very low output impedance by using a variation of the White Cathode Follower. The circuit uses no negative feedback for more natural tonality.