Op-amp gain trouble

[Guitarik]

channels 13-24 are only line level inputs?

[High C Double G]

Hi,

There are a lot of inputs on the d8b... On Fader Bank 1, Channels 1-12 have a integral microphone preamplifier for microphones with a trim control - Chapter 1 Page 7 in my d8b v5.1 manual.

Do you have your copy of the manual?

Dbl High G

[Guitarik]

I see Ch1P14 uses line levels on inputs 13-24. do you use preamps? if so what do you use for them?

[High C Double G]

Hi,

The block diagram on Ch1Pg14 shows the difference between channels 1 through 12 compared to channels 13 through 24. Channels 1-12 have already a pre-amplifier to boost the input signal for microphones and channels 13-24 do not have the pre-amplifier.

Any thing that will boost (match) the input signal to line level (+4) will work to get a strong level on channels 13-24 - a microphone pre-amplifier is the best solution for microphones. There are many products available that will help to match the signal that might not be a professional +4 signal to what the d8b wants to see which is +4.

If you are not recording everything at once, you can route the channel inputs 1-12 pretty much anywhere you want - it is a incredibly flexible mixer - it is all in the manual.

Hope this helps,
HCDG

[Guitarik]

I see.. I assumed the mic/ line switches on 1-12 were merely pads and all the pre-amps were uniform. I dont think i ever came across a mixer that had only line level on 1/2 the preamp inputs.

[Guitarik]

Still the same problem... I ran a line-level input and the gain is still weak -15 at full gain on the HA. Something is not right.

[Crash]

Still the same problem... I ran a line-level input and the gain is still weak -15 at full gain on the HA. Something is not right.

What did you use as your line input device?

[Guitarik]

I'm using a motif and I had it at max volume

[Crash]

I'm using a motif and I had it at max volume

Line and instrument out are different. I am guessing the motif is a keyboard? Try plugging in the output of a cd player or an F/X box (Not stomp box) and see what you get. If you have an external preamp, plug your motif into that to get it up to what channels 13-24 are looking for. I think your d8b is working as it should from I have read here.