S-F2 with Tone Tubby

[strangerones]

So, I few weeks back I had a Tone Tubby cab delivered with 2x12 alnico hempcone speakers.
 
I'm powering it with a Mesa 2:50 power amp (ultimately will be powering two cabs).  The guitar is a Skylark.
 
I've tried using the S-F2 as my preamp, though with little success.  It seems the only way I can get a decent sound out of it is by allowing all frequencies through, and even then, it distorts quite a bit whenever more than one note is played at a time.
 
I then tried out my PODxt to use one of the amp modelers as the preamp, and took out the S-F2, and discovered the best sounding rig I have ever owned.  I then added the S-F2 back into the chain after the PODxt.  The distortion problem is gone, but I still can't get any use out of the S-F2 except as a volume boost.  All turns of the frequency knobs can have either no effect, or a very drastic effect, with no middle ground.
 
I find this strange, as prior to this I was using the S-F2 with a Fender Bassman with excellent results.
 
Anyone have any ideas what might be going on?
 
My original plan was to use all this in conjunction with an F-2B to phase out the PODxt (I hate the thing, really), but if the S-F2 is any indication of the way Alembic preamps interact with this particular setup, I'm not so certain...

[lbpesq]

James:
 
Have you gone inside the SF-2 to see how the pre-amp is set?  It can be set for 0, 10, or 20db amplification.  Try playing with these options to see it it improves your sound.  Also, how are you hooking it up for use as a pre-amp?
 
How many watts are you running through the Tone Tubby's?  I looked at them, but it seems the maximum wattage is 40 watts per speaker.  I'm afraid my Boogie would blow them out!  How's the sound?
 
Bill, tgo

[strangerones]

Bill,
 
I have not opened up the SF-2.  Actually, the thought of opening it horrifies me.    
 
I've tried both plugging into the front input jack, as well as the mono input in the back of the unit.
 
The power amp I'm running has 50 watts per channel, and I'm only using one channel.  Does 40 watts per speaker mean I could effectively run 80 watts to a 2x12?  My knowledge of the science behind it all is still very limited.  
 
It sounds great.  Very warm and clean.  For the first time in forever I don't feel as if I'm struggling with my sound so much.  I just wish I could get this preamp thing figured out.
 
I thought I could try running it before the PODxt, so the chain would be SF-2>PODxt>Mesa>Cab.  I'd need to go get another long cable though.
 
Thanks,
James

[David Houck]

My guess would be an impedence mismatch; for which you might try Bill's suggestion.  If the Pod or Mesa have a pad adjustment that might work too.