Please Help - Connecting Compressor to Pre

  • Thread starter Thread starter NotPaul
  • Start date Start date
N

NotPaul

New member
Hi All,

I'm new here and have a simple question. I just bought a dbx 266xl compressor and a dbx 586 preamp, both on ebay. (Both a dual channel units) I'm using ProTools with an Mbox2 and want to add these components.

I come from a long line of techincally challenged people ... A good friend reccomended that I buy insert cables to connect the two. The compressor has a sidechain jack, so I plugged in the single cable of the insert there, and the send and receives into the pre. (I followed the docs I found onlline, so the tip and rings should be in the right jacks; alternatively, I've switched them around to double check).

I then plugged the outs of the pre into the ins of the MBox, using TRS cables.

So, here's the problem. I plugged my bass into the I of the pore and got signal -- everything worked -- gains, meter, EQ. ALso, the compressor lights were working, although I couldn't hear anythinig from the compressor. This preamp has an INsert switch, which I think is supposed add the compressor signal. However, when I depress it, I get nothing. No sound, no signal, no meters.

I've never used sidechain before; I thought this was supposed to work like an effect loop on an amp (and I think I could easily hook the units up through their I/Os).

Any help would really be appreciated.

Many thanks in advance.

Andy
 
Inserts create a loop from an input & output.

Side-chain is a SIDE chain -- You're feeding a different signal to TRIGGER the compressor - Such as when you feed a vocal line to the side-chain to push down a music bed. The music bed is "going through" the compressor - The vocal in the side-chain is actually telling the compressor when to compress the music bed.

In other words, at this point, don't worry about the side chain.

Now - Whether you should be compressing your input chain is a story for another thread...
 
Tahnks for answering -- I thought there might be a difference between sidechaining and creating a loop.

So - yes, I do want to compress my signal going in (for bass, vocs, acoustic guitars, etc) and I realize this needs to be done moderately.

Can you tell me the best way to hook the two units together? Can I use the insert cables I bought? Or should I get new TRS cables?

Thanks
 
Yeah, use the insert cables. The TRS end into your preamp insert jack, and the 2 TS ends into the input and output on the compressor. Then run the line outs of the preamp to the TRS line ins on the mbox using TRS cables to maintain the balanced signal. Do it the same way for both channels.
 
The problem is that the pre doesn't have a insert jack -- just I and O. However, it does have Send and Receive, which I imagine I'd (somehow) use to plug in the compressor ...
 
Thanks mixsit and everyone! The way to best connect these seem to be the example in the manual, which mixsit provided.

A good friend of mine made a valid point -- there's not always a consistency in naming. While the preamp has an insert button to enable to compressor, when it's connected, it does not have an insert jack (just the Send and Recieve, which, essentially, do the same thing).

So, the compressor is looped into the pre, just like one would loop guitar effects in an amp -- the Send of the pre connecting to the Input of the compressor, and the output of the comp going to the Receive of the pre.

MIke/instrument gets plugged into the I of the pre, and the Out goes to the Mbox.

If anyone has a better way of doing this, please let me know. I did want to thank you all and pass along the "naming" issues, which initially confused me.

Why can we all get along ... :)

All best!

Andy
 
Last edited:
You can use the insert or just keep it in line. Won't really make a difference (one less cable in-line).

Keep in mind to set your input levels *before* engaging the compressor -- Too many people track way too hot already. Then they add a compressor and overdrive their input chain. Set your level, engage the comp, don't bother with the (almost certainly noisier than digital) make-up gain.

I'm still pretty heavily against any sort of dynamics control at the input stage... There's no "undo" and there's no advantage (and so many disadvantages). Just something to consider. And it's a 266XL... If you can leave that out of the chain completely, you're going to make better sounding recordings all but guaranteed. I'd avoid it if at all possible.
 
Thanks Mike. I usually track dry, too, but I do want a little compression going in, esp on bass.

Not sure how I would use the insert cable with my rig -- would I plug the TRS into the compressor's I, and the R and T into the pre's send/receive?

BTW, where are you in CHicagoland? Im in Oak Park.

Andy
 
Looks like TRS type insert cable doesn't apply here. It in this case your choices are separate 'send and receive cables like you correctly mentioned or run the pre's out put into the comp like Massive said.
Notice dbx's routing puts the insert (comp) ahead of the eq, (good to know) but doesn't say whether the 'level control is actually on the final output after everything else or not.
 
You must log in or register to reply here.
Back
Top