Several decades ago I had occasion to help design and build a location recording truck. We decided to build a console from the ground up to meet some requirements that weren't readily available off the shelf. In the end we built an up specced 1600. In addition to P&G fader, Allen Bradly sealed pots, heavier channel strip extrusions the biggest improvement we made over the original was installing a very heavy duty star ground system. We installed a one inch by quarter inch copper bar the length of the console, connected pin one of each mic input directly to the bar with 14 gauge wire, connected each channel strip ground with a similar wire directly to the bar and connected the bar itself to the power supply ground with a large gauge speaker cable with all four conductors just for the ground. No multipin for the PSU connections, those were all done with spade lugs to barrier strips.
Big copper grounds are good for what ails ya.
Big copper grounds are good for what ails ya.
Even heavier extrusions? Wow, they're already plenty strong!! Must have been built like a tank!
Funny you should mention the grounding.
As they get recapped, each strip has been getting an 18ga ground wire to a copper bus bar, with those automotive spade connectors in the middle for disconnecting each strip.
I have some "before" noise measurements from before doing any mods.
Since I still have the original grounding intact (via the ribbon cable) I'll be able to get some actual measurements of what others can expect from doing the ground mod, recapping the desk and power supply, and doing both, which will be interesting.
Funny you should mention the grounding.
As they get recapped, each strip has been getting an 18ga ground wire to a copper bus bar, with those automotive spade connectors in the middle for disconnecting each strip.
I have some "before" noise measurements from before doing any mods.
Since I still have the original grounding intact (via the ribbon cable) I'll be able to get some actual measurements of what others can expect from doing the ground mod, recapping the desk and power supply, and doing both, which will be interesting.
On the mackie schematic the line input goes through the mic preamp, heavily attenuated though. Are mixers usually designed like this, or is the mackie an exception? IMO the line in should bypass the mic pre.
I am sorry but I don't have time now to review that design.You find countles reviews on mackie vlz and onix lines.They probably get better thd figures with more open loop gain in line topology using the mic pre and obviously much lower noise.