morricab wrote:

…. putting the attenuator AFTER the gain stage has negative consequences for the sound….

Well, yes and no. In the new 6 channels version of Super Milq I will be use 2 stepped attenuators: for Injection Channel and for the Tweeters. Both of them will be line level, sitting between the input jack and the first stage grid, so essentially the resistors will be driving a few inches of cable – not a big deal at all, particularly cince I do not need in both channels any LF…

Surely the advantages to roll off voltage at line liven are very obvious, and do not forget that you have the tubes ruining at lover grid current – always helps… However, I would propose that the line-level advantages are inversely-proportionally to frequency. When we have any more or less LF driver then it has a lot of reactance that is being return back to amplifier. A speaker acts like a motor-generator sending the waves across the cable. Many aspects of dumpling in place in there and when we put a resistor (regardless of its location) then the resistor begins to play in this game. I, for instance, clearly hear change in sound when I put .3dB divider on my LF section.

However, with HF the effect is different. The tweeter reactance back to amp is negligible, dumping is way less critical and the presents of a resistor at speaker level is not so critical. I will still go for line level though in my case…