Drubin is correct about the input impedance issues with Aleph amps.
I borrowed an Aleph 3 from Viggen for a few weeks and loved its sound but the 23K ohm single ended only input impedance resulted in some bass loss and dynamic constriction when mated to my Blue Circle BC21. Gorgeous guitars though!
The Aleph 30 added balanced inputs and raised the input impedance to 47K ohm in hopes of addressing this issue. I believe some of the other Alephs were as low as 10K ohms.
Most of the problems I've heard of with the Alephs had to do with passive preamps and to a lesser degree tube preamps, but solid state preamps should have an easier time mating to the Alephs.
It seems many people try to stay in the 10-100 times range when matching a preamp's output impedance to an amp's input impedance.
Good luck!
I borrowed an Aleph 3 from Viggen for a few weeks and loved its sound but the 23K ohm single ended only input impedance resulted in some bass loss and dynamic constriction when mated to my Blue Circle BC21. Gorgeous guitars though!
The Aleph 30 added balanced inputs and raised the input impedance to 47K ohm in hopes of addressing this issue. I believe some of the other Alephs were as low as 10K ohms.
Most of the problems I've heard of with the Alephs had to do with passive preamps and to a lesser degree tube preamps, but solid state preamps should have an easier time mating to the Alephs.
It seems many people try to stay in the 10-100 times range when matching a preamp's output impedance to an amp's input impedance.
Good luck!