Which Lundahl MC transformer is best suited for low-output MC cartridges, for example Ortofon SPU?

For low-output and low-impedance cartridges, for example Ortofon SPU, the LL1941 is often the best choice, as it can provide both 1:16 and 1:32 step-up ratios. If the solution should be more affordable, the proven LL1681 and also the LL9226 are good alternatives. For low-impedance matching, it is important to choose the higher step-up ratio.

From experience, an LL1941 set to 1:16 sounds more airy and homogeneous than an LL1931 at 1:16. For very low-output systems and less sensitive inputs, the 1:32 step-up ratio is preferable.

If the phono input is not terminated with 47 kΩ, as is usually the case, a parallel resistor should be connected to the transformer output so that the transformer can work cleanly and the system sees a sensible load for damping.

The LL1943 would also be conceivable, as it may offer advantages in the bass range; however, in terms of dynamics, the LL1941 has the edge.