analog for the people!
Oh I missed that little proto board at the back of your PSU...huh! I see the two caps, resistor annnnd...is that a little TO-220 IC on there? Can't tell where the wires go/come from. You ask anybody on the MCI forum about that?
Not yet, I'll get some pics and info up and see what they think. On closer inspection, it's got a couple 4.7uf/160v caps, a few resistors, a couple small diodes and what you're seeing is an LM317, and in the pic above you can kind of see where its wires are soldered onto some Molex pins at the top right corner of the large PCB on top of the big trafo. I need to stick my nose in the schem for that board and get a feel for where in the 600's world it actually IS.
I can't wait to hear my JH-416 too...gonna be awhile, but it'll be fun getting there. Focusing on finishing up my Soundtracs cleanup first...16 channels to go...and getting the MM-1000 working reliably and getting it calibrated...getting a working studio basically, and that's all on the back-burner right now with more important projects here at home. All in good time.
For sure! I'll be interested to find out down the line how it compared to the Soundtracs, which is a good board in its own right. I expect they will sound and handle quite a bit differently, for better or worse!
Are those cinch Jones connectors inside your PSU? The one with the proto-board? And I just really like the backplane on the mixer frame. Their mixer design really went through vast changes in refinement from 400 to 500 to 600. So many great little ideas you know?
Yes, there are cinches connecting the regulator boards into the audio PSU since they're mounted on removable "chimneys" that pull out for easier cleaning/servicing. Each PSU also has cinch connections on the PSU side of the the cable looms that connect to the console.
The funny thing is that the 600 series was the replacement for the 400 series. The 500 was built in tandem with both the 400s and 600s for parts of their production runs and was always the flagship. The 600s are certainly a departure from the 400s for being a "replacement," though! It really speaks for how much the industry changed through the mid and late '70s, though I would imagine there are some "family similarities" going between the 400, 500 and 600 particularly when it comes to routing.