Calrec1061 PREAMP redesign schematic - thoughts?

[quote author="Samuel Groner"]You're faster with typing than I am with editing...[/quote]Haha must have just caught it the moment you posted!

Concerning PCBs - the amplifier I have done has a ground plane on top for the analogue and another on the reverse side for power ground (bypassing rails etc) they both come out onto separate pins and my plan was/is to have the power run on one side of the main PCB along with its ground and then signals / analogue ground on the other. Then at a single point on the main PCB I will join both top and bottom layer planes to create a single ground point, this will then go to chassis bolt along with the any ground connection from an EQ PCB via wire. This should ensure a lot of copper in a small space for ground, sound like a good plan?

As far as C11/12, well they are the 48V bypassing and are going to the power ground which would be bottom layer ground plane until it joins the signle point and then on to chassis bolt...I thought all phantom bypassing went to PCB ground?

RE the shorting gain switch - well as I understand it, the resistors from two positions will parallel for a microsecond so the amount of gain will go up above the desired amount slightly. i,e 20-25dB might be 28dB as the resistors parallel etc I think but not too big a problem.

Thanks again Samuel

I'm really not of much help regarding the grounding. I've found it straight forward to reference everything to one very low impedance ground as this seems to keep the current flow as local as possible. It looks to me as if in your suggested solution the impedance of both ground planes is effectively in series with the bypass cap. That would reduce the effectivity of the bypassing. But I might be wrong so I'd appreciate comments from more experienced people!

Samuel

Wow this place has a fast turnover - this dropped to page seven in double quick-time....

anyway thanks Samuel, I have looked at some more grounding examples and learnt a little more so I will change my approach a bit, keep it nice and simple.

-Tom