Adding DI to PM2000 mixer input channel?

[JW]

Hey folks,

Can someone tell me if there is a good place to add a DI to this circuit? (attached word doc, first diagram)
It would be nice to just be able to plug directly into the console on a couple channels. I remember doing it with the PM1K channels a long time ago. But obviously this is a different circuit.

I'm thinking of just putting a couple 1/4" switching jacks in place of the "cue" buttons.

Here's the schemo: www.rylandbouchard.com/files/PM2000-Schematics.pdf

 

[jwhmca]

the .DOC has black boxes...? Maybe a JPG?

 

[JW]

Hey folks,

Sorry, I asked about this a long time ago, but never got back with a readable schematic. Anyway, now I'd really like to implement it. It would be nice to have a DI on a couple console channels so I can plug in guitar pedals on their way back from reamp duties.

Anyway,
Here's a link to the schematic.

www.rylandbouchard.com/files/PM2000-Schematics.pdf

 

[mitsos]

First, I've never done this to any mixer, but you can usually run an instrument direct to + input of an opamp (usually with a cap in series, but not necessarily).  I don't know how well this will work here with their gain switch, and that ferrite bead.  What I would probably try first is removing the FB, then take the "left" side FB pad to the switching contact of a 1/4" jack and the other pad (closest to IC1) to the tip.  Choose your ground according to lowest noise, I usually do this on API preamps and ground near the opamp.  Ideally I would put a relay in the picture to switch the DI in and out of circuit when an instrument is inserted and avoid wiring the signal back and forth, but this normally works fine.

 

[Winetree]

You can use a direct box onto the mic input.
Or I remember reading in the PM-1000 manual how to build a T-pads for various input levels.