Can you provide a more detailed description? Does it happen when Cubase scans the VST plugins on start, or when you do it manually from the Devices->Plugin Information menu? What do you do to make it reappear?
Really sexy sound, the only downside is the delay because I have to route a signal through two channels if I want to mix the dry signal into the wet signal because adjusting the dry/wet knob in the mixer in my DAW just gives me phasing from the delay.
I still route it through two channels though it's totally worth it on my drums to make the kick into this earthquake fart sound.
That's a really interesting one. There are two places where the delay could be introduced. One is the cathode capacitor, but that's inherent to the modeled circuit and shouldn't cause any problems (try the 22uF setting just in case). The other one is the oversampling. It will introduce 8 sample delay. You can try to turn off oversampling and see if it helps (button in the upper part of the UI). Unless you drive the tube very hard you can get away without oversampling.
I will check if there are no other glitches with delays and get back to you shortly.
Now it comes to my mind that a delay-compensated dry/wet mix know could be handy.
Ok, I think I've got something. The nastiest phase interaction comes from the fact that it's an _inverting_ triode stage. I've kept it as is in the model but nothing is keeping me from changing it to non-inverting.
Cathode cap indeed introduces some phase shifting and will attenuate some frequencies when output is mixed with dry signal.
Oversampling severely affects the phase, so dry/wet mixing is not possible with oversampling in the current implementation. After DC-12 is finished I will add mix control in the future version that will be phase-corrected. As a positive side effect it will make the transfer function plot in oversampled mode a bit more meaningful as well.
I'm going to fix the invertion and release an updated version soon.