It is interesting where the reverb is put and I think it’s a massive part of the sound as to where it actually is.... whilst it’ll be nice for variety to be able to put the spring after the amp, for maximum ability to sound like an old spring reverb it actually needs to be before the amp as was said in the original Kemper announcement
‘Vintage combo amps do not feature a preamp distortion, meaning that the power amp needs to be clipped to achieve a gritty sound. Due to the placement of the reverb tank before the power amp, its output will be distorted along with the dry guitar. To authentically recreate this effect in the Profiler, you should place the Spring Reverb before the Amplifier. However, if you place the Spring Reverb after the Amplifier, you can then enjoy it in stereo.‘
I have a Matamp which has spring reverb and, because it’s a dead simple amp which I’ve opened, you can see where things fit. The actual amp itself has valve (tube for those over the pond) preamp and power amp. Once the signal has gone through the preamp valves, the signal splits. With the reverb turned all the way down, everything just goes to the power amp valve. But when you start to turn the reverb up, there is signal sent to a solid state preamp feeding the spring reverb tank. The output of the reverb tank is amplified using another actual valve and this is mixed back in to the ‘dry’ preamp signal. So, in my amp, it’s as Kemper describes with the old vintage combos as in the reverb is actually not ‘before’ or ‘after’ The the amp block but it’s actually in the middle between pre and power amps.
I guess for authenticity that perhaps profiles made from amps with clean preamps that rely more upon the power amp distortion may sound more authentic as we don’t have the ability to split pre amp from power amp in a profile.... Part of the joy with a Kemper (and there is a lot of it!) is that you can get the sound of a power amp melting without blowing out the windows so we can all experiment with springs here, there and everywhere to get as close to the old ones as possible but also create new things. This is really nice.