Are Channel Inserts Pre or Post Channel EQ??

  • Thread starter Thread starter monopole
  • Start date Start date
M

monopole

New member
I make home recordings of bands, and I'm now asked to make live recordings at fairs and small stages. I have been successful so far.

I recently bought a Yamaha mixer with the intention of using the channel inserts to feed my Alesis HD recorder. I've been using three Mackies to get enough inserts to record 12 channels. Naturally, this made monitor feeds a nightmare. The inserts in the Mackies was just after the HPF and before the Channel EQ.

Believing this to be a standard, I bought a Yamaha MG32/14FX. At last I was going to have enough inserts to run my Alesis and mix for FOH and at least four monitor channels. I was wrong.

Whatever I needed to fix the sound for the house--especially changes made during a performance--screwed up my recording levels. Then I found out why--The Yamaha places the inserts post Channel EQ.

I had assumed that the inserts were pre EQ. Damn. So, I called for a service manual and am biting the bullet because I am going to modify 24 channels to put the Inserts where I want them.

Has anybody here done this? Does the Behringer SL3242FX-PRO place inserts pre EQ? Although the Behringer is not my first choice and seems to cost half as much as the Yamaha, I'm debating buying one as opposed to modifying the Yamaha. The Behringer is said to be a bit noisy on the AUX SENDS. Oh, well. I feel like I'm pushing rocks up a hill. You can tell the pioneers by the arrows in their asses.

I've managed to make a few surround mixes with my existing equipment that are not bad for a first try. Email me if you want to hear them.

<buzz-at-zz.com>

Cheers,
Buzz.
 
If you like the Yamaha, and it was designed so that is an easy mod, I would do the mod. Wait for the service manual and see.

I modded my A&H to make the direct outs prefader, that is an easy mod, but the A&H was designed with that in mind.
 
I do like the Yamaha. It has a smooth, easy sound and lots of headroom. The manual came, and I have to dig into some theory--ie: why is there a 220_ohm resistor in series with the insert. It has a traces on both sides of the boards and wires only in jumpers between boards. The external jacks go right to input boards. And I had to buy the extended warranty. Oh, well.

I have the Road Ready box for this mixer, and the thought of sending all this back just to get a mixer I don't really want but does have the inserts right is just not what I want to do. I'm keeping the Yamaha.

The combination weighs around 100_lbs. I have a pure sine wave inverter that allows me to go onto a dry lake bed without a generator and get dead quiet sound.

I remember reading that your mod was anticipated by A&H and that they provided the how-to for the mod. Never thought I'd be doing this, however.

Thanks,
Buzz.
 
monopole said:
I do like the Yamaha. It has a smooth, easy sound and lots of headroom. The manual came, and I have to dig into some theory--ie: why is there a 220_ohm resistor in series with the insert.

It prevents an overload in the event of a short.

It has a traces on both sides of the boards and wires only in jumpers between boards. The external jacks go right to input boards.

Yeah, that would be typical of boards in that range. However there might be jumpers somewhere on the PCB that can be reconfigured.
 
originally posted by mshilarious
It prevents an overload in the event of a short.
I figured it was something like that, though the schematic has the circuit isolated by a cap from the OPAmp output to the resistor to the INSERT Send. The INSERT Return is direct to the next stage, AUX 1-6. I plan to leave the resistor on the connector board and reuse it for my new path from the output switch on the HPF just after the GAIN. Unfortunately, there is no easy place to hang the Return to. I'll find one, but I'll have to cut a couple of traces to keep the path simple.

However there might be jumpers somewhere on the PCB that can be reconfigured.
I'll know more when I crack the box--about 40 screws later..

Thanks for your confidence!

Cheers,
Buzz.
 
Last edited:
Well, I opened the box and found multiple input cards with little wiring--just card to card cabling. None of the channels were the same of the eight on each card, but each input card was the same as the next. I marked the traces to be cut and found capacitors that could be wired together.

The traces were cut with a Dremmel, and the wires were carefully laid out and RTV'd to the board. Soldering was wierd--I think Yamaha is using a NO-Lead substance that required about 500_F to melt.

I completed Ch_01, rebuilt the box, and tested it. No unusual or additional noise, and it worked as it should. Several long nights later, I had the first card finished. All the screws back in place, it tested out just fine. I was concerned that I would introduce feedback or hum or noise, and I got none of that.

I'm going to sit on this achievement for a while, and then I'll tackle board number two. I'll probably have the only Yamaha MG32/14FX with inserts ahead of the channel EQs. I'm going to get what I want after all.

Cheers,
Buzz.
 
Last edited:
Back
Top