Balanced/Differential tube preamplifier recommendation?

bushing in the design. @atmasphere ok, I understand. In the units with a motorized attenuator, do you just use a regular potentiometer?

@thought9 Yes, if a 4-dech control can be considered 'regular'. Turns out that due to a change we made in the volume taper about 8 years ago that the difference between the stepped control and the pot was mostly eliminated.

@atmasphere mostly eliminated.

in that case why not make the full switch? Your popularity seems to be shunted majorly by the lack of a remote control being standard in your offerings 

@atmasphere no offense meant by the way. I just mean to convey that today, remote controls are very important to most audiophiles, especially at the level that your firm operates

@thought9 I get it- back in the 90s we studied the remote issue for years; nothing was out there are the time that was at the level of our master control in the MP-1. So that remote didn't show up until the early 2000s. The MP-3 was harder due to the Electroswitch control, which was already a custom part and we are pressed for space. However the big change we did several years ago with the volume taper took a lot of issues off of the table. I used the phrase 'mostly eliminated' the same way one would use the word 'virtually' in that there is likely a difference, but I can't hear it and the preamp actually measures better. I don't doubt that someone might hear it (or claim to, which is different...). The trick is eliminating issues with Miller Effect at the input of the line stage. By changing the taper and the overall value of the control we vastly reduced the Miller Effect problems.