Which preamp for Symphonic Line Kraft amps?

Jonathan,

600 Ohms may be too high. 100 Ohms is more like it. Remember the SL tube preamp has 100 Ohm ouptut impedance and the SL RG4 RG3 preamp has a 1 Ohm (not a typo) output impedance. If you had the opportunity to try the CAT, that would be ideal. Make sure the stepped attenuator does not provide too much gain and not enough resolution on the low end of the scale. Very few tubed preamps have low output impedance. In your case, it may not matter because the preamp drives the crossover. The crossover is responsible for driving the amp and that should be tested before purchase.

Jay;

Thanks again for the observations - you're right that since the crossover is what's driving the amps that's what counts. I also have the stock solid state crossovers that come with the speakers and they have an output impedence of 50 ohms. I have to say that I much prefer the tube crossover - its input impedence is 60k, and the stock Dali crossover is 20k).

In years past I owned an RG-1, an RG-7 and the RG-4 monos. I tried a few different preamps with each of them but in the end CAT preamps always produced the best sound. The RG-1 was mated to a Sig. 1 and the RG-4s were mated to an Ultimate. Truly wonderful sound.

I now use the SL Kraft 250 and the SL tubed pre. I previously owned a CAT Ult MK2. I have also heard the SL SS pre with the Kraft. Bombaywalla and Jay are both right.
The SS SL with a 1 ohm output produces deeper tighter bass than the tubed SL or the CAT. The tubed SL does other things somewhat better than the SS SL. It is a matter of taste but I would choose either over the CAT. You may end up going back to the SS crossover to drive the amp correctly and may want the things tubes bring from the preamp.

Bart

Bart;

Thanks for your reply - I was hoping I might hear from you as I'd seen a couple of your posts on Audio Asylum about auditioning the SL SS preamp and then purchasing their tubed unit.

Once I get the Kraft amps I'll have to see what happens using both the tubed and stock crossovers and then make my decision about going solid state or tubes when I upgrade my preamp.

Regards,

Jonathan