Yet another transimpedance question

@lewm 

Yes, exactly, that is what it does, I only mentioned the 555 chip since eliminating that might allow some benefit to an external LPS, though my understanding about this is very (as you can tell) limited.  Without the jfet (as in the Trumpet MM) one still need to increase the gain...

@salectric 

I really got the Piccolo more out of curiosity since it is inexpensive (a good SUT assuming I find a good match first time, could set me back 5 to 10 times the cost of the Piccolo).  Perhaps in the future I will go the SUT route, though that path is not without its own issues.  I do like the Hayate through the Piccolo better that straight through the Trumpet MC, so we'll see where things go..

Thank you both for your input

The 555 is providing a benefit that you would not want to eliminate, if I’m correct that it delays turning on the high voltage (B+/B-) until after the tube filaments are powered up. This prolongs tube life. And if that’s the case, the 555 is not in the signal path and has nothing to do with the JFET.

Modern switching power supplies are just fine.

I hadn’t thought of that, of course you are correct and most like the 555 chip would also be in the Trumpet MM (or some way to have a “soft start” function as well.  Just no jfet.  Thanks, I think that pretty much answers my question.  When I have more time, I’ll look at the MM schematic to see what I can as well.