Preamp stompbox

[royster]

Can anyone suggest a clean preamp stompbox for my pedalboard? I want to connect my pedalboard straight into the power amp section of of my combo and so bypass the preamp in the combo amp  It is a Carvin Amp. I think I need some kind of preamp with tone controls to boost the signal into the power amp

[JebemMajke]

Clean or dirty?
If clean go for FET version of Alembic F2B.

[ubersam]

Clean or dirty?
If clean go for FET version of Alembic F2B.

I second that, but with some changes.

Here's the Fet2B: http://www.diystompboxes.com/smfforum/index.php?topic=73173.0

What I have done:

I took the "Normal" preamp section of the Bassman schematic (AA864, or 6G6) and turn that into a two Fetzer Valve stages with a 'marshall' tone-stack in the middle and a 100K volume pot at the very end. J201s weren't clean enough for me so I chose JFETs with higher Vp. I used J305s (Siliconix) but 2N5457s and 2N3819s also work with good results. Also, I'm running the circuit on ~18V using a charge pump.