312 with 1646 output... can someone please check my schematic?

Hi all,
So I have a goal to make a 312 with (choose at install) trafo or 1646 output. Here is the schemo I drew up for this.. based on the original with various other things from hints from different people/schematics here and elsewhere.

Before anyone asks, the 2caps+resistor in parallel is how I've heard API are doing things now (haven't seen any new API stuff open so can't say for sure), but is also the way Eisen audio has their kit set up.  I tried it out and it worked well for me on a couple of other boards. The 1646 is straight off the datasheet... all this unless I made a mistake... like is my pot turned right side up? Are the switches correct? Anything else that stands out?

Anyway, I tried this with a DRV134 chip in an SSL9k balancing board and it worked well (even with shabby components/wiring, so hopefully it will sound spectacular when done properly).. Tried it with a melcor and a Hardy 990, both sounded good.

I realize this project is a bit been there, done that, but if you have any comments, I'd really appreciate it. Thanks!

Looks like Lay Out and CAM files time to me.
(at least a test etch)
Best of luck.. bet it sounds sweet !

GARY

Something you might consider.
A footprint for an optional zobel network in parallel to RL might be useful if someone uses a different transformer.
R12 looks pointless with a 1646 behind.
Powering the 1646 from the opposite side of D5 and D6 would also protect this chip and not only the DOA from a miswired supply.
From 1646 datasheet C11 and C12 look like NP caps. Dunno if it matters.
At least a footprint for 4 diodes at 1646 out for surge current protection might be useful. (see pg.9 of datasheet)

Thanks for the replies guys... the layout is gonna take me a while.. It's not really done yet.. I am still deciding whether to add some type of LED "metering"... Or maybe some peak indicator.

R12... to be quite honest, I'm not 100% sure what that does. I was told about it as the new APIs using it in parallel to those caps, so I kept it in. It works with either the trafo out and chip out options in the proto..

Harpo, I updated the schemo to reflect most everything you said. C11 and C12 are in fact NP, but the only NP caps in eagle were axial and I had lots of trouble changing the symbol, so I left it like that.. I'll try to get that fixed though so not to cause confusion.
Added the zobel, swapped the power to behind the diodes, and added the other four diodes just in case.. I gotta double check those...

Does the phantom switch look right? I mean will it give phantom and light the LED when depressed? simple stuff I guess, but not for me

Thanks again...

(will be offline most of today and maybe tomorrow, so if I don't appear it doesn't mean I forgot!)

when placing components, also place the junctions (there are >20 missing). I know how it was ment by you, but eagle doesn't and if you build it as drawn, it won't work (especially at C11/C12).
For the missing bipolar caps just reload my still unproven library.
Led/phantom should work, but already using a DPDT switch, I'd probably power the led from another available rail.
If this led breaks for whatever reason, this 48V might get dead shorted to your grounded frontpanel and comming from a LM317 this regulator might die (hopefully open) from exceeding its max.i/o differential voltage. With the same amount of parts something like this scetchup might avoid this. YMMV.

Cool!! thanks for the library! I will be back on my computer (with eagle) monday night or most probably tuesday morning.  I'll add all the junctions and stuff and post back.. Thanks again!