Low input levels on 828MKII/ Gain adjustment does nothing

Bridgy · Post by **Bridgy** » Wed Mar 29, 2006 10:33 am

Hi, I have had my 828MKII for a couple of days now. I have it hooked up by firewire to my PC running XP and SX3. My issue is, I have a drum machine connected to analogue inputs 3and 4 on the 828. The volume of the drum machine (which I understand to be a line level device) is on full but I am not getting much signal level though into SX when recording. I have tried adjusting the gain for the two 828 input channels from the motu front pannel but it has no effect on the levels recieved by SX (or to the main outs of the 828 for that matter) even if I set them t both to Unity or even off. The only way to get a half useable level is to set the channels to -10db and use the +6db option as well !!! This can't be right for a line level device !!! It seems that adjusting the input channel gains from the front pannel of the Motu has absolutely no effect on what gets sent to SX over the Firewire or to the main outs. Before you ask, yes I have the input channels routed through to the main outs for the mix I am using. Another thing I will mention is that I am not using the cuemix software and have the link to cuemix dissabled in SX (Hardware monitoring is unchecked). All I am after really is how the heck do I get the Gain adjustment to actually do anything when adjust it from the frontpannel of the 828MKII.

I hope you guys can help. I suspect (hope) that it is that I have completely missunderstood how the gain parameters are supposed to work

Smokehouse · Post by **Smokehouse** » Wed Mar 29, 2006 10:51 am

The gain adjustments on the front panel are, as I understand it, only CueMix gain settings. That is, how much of that input channel is fed into MixBus 1, 2, 3 or 4. It does NOT provide input gain on its way to FireWire and beyond. Checking the LED meters on the front panel for channels 3 and 4 (your inputs), turning the gain settings up and down will have no effect.

So you either have (1) low outputs from your source or (2) defective in inputs on your 828mkII. The way to solve any problem like this is "divide and conquer". Find another source with a line output (like a DVD player or something) and feed channels 3 and 4. Do you get good levels? Now take your source and feed it into the Line In on some other piece of pro audio gear (got an old mixer or something? -- or take it down to an audio store). Do you get good levels?

Bridgy · Post by **Bridgy** » Wed Mar 29, 2006 11:03 am

Hey Smokehouse, thanks for your quick response matey. I did wonder if I missunderstood the use of the gain section of the Motu. I am from a live sound/mixing environment and am used to gain meaning what it says gain for the input and not what it does hear which is more like setting levels relative to other levels in a mix. I will do what you suggest and see if it is the same accross all inputs with some other gear as well.
Thanks agin for clearing the gain thing up for me though, could of fiddled with that for hours !!!

Cheers
Bridgy

Bridgy · Post by **Bridgy** » Wed Mar 29, 2006 11:31 am

Hey Smokehouse, I tried my Line6 POD XT Pro (guitar processor) into a pair of inputs on the Motu and again, to get anything close to 0dB level on an SX3 audio input channel, I have to set the inputs on the Motu to -10dB and have the volume of the Line6 processor on max. I guess it is useable like that but I hate having to set everything to their max levels. I am now getting concerned that there may well be a problem with the inputs on my Motu828MKII

mothra · Post by **mothra** » Wed Mar 29, 2006 11:39 am

Well a Pod is a -10 device (not sure if the Pro is different or not) and with mine as well, some models have to be fully cranked, others will redline about halfway up. Depends on the model and settings..

Id bet your drum machine is also -10 did you have it set at +4?
Theres also a boost button there for this exact purpose.

There is no gain adjustment on the line inputs other than -10/+4 and the boost. They were made so you control your overall level from the device going into it. Theyre not mic pres so anything with a sub-standard signal level is the fault of the devices manufacturer..

You should always have any MIDI or outboard devices up as loud as they can go before going into the MOTU.. Your signal to noise level is much better when you do.

Smokehouse · Post by **Smokehouse** » Wed Mar 29, 2006 11:55 am

Bridgy,

Just to be sure, don't look at the SX3 level. Instead, let's talk about the LED meters on the front panel of the MOTU unit. (That way we don't also have to worry about how the software is configured. Again: Divide, Isolate, and Conquer!!)

So, are the front panel LED meters also chronically low?

Bridgy · Post by **Bridgy** » Wed Mar 29, 2006 11:56 am

Yes, all the analog inputs were defaulted to +4dB when I first turned on the Motu from new. I am glad that it sounds as though my unit is functioning as it should and as you say, I still have the +6dB to use if I am really stuck.

Thanks again for all your help matey, I know who to ask for when I come across my next Motu issue

Bridgy · Post by **Bridgy** » Wed Mar 29, 2006 12:06 pm

Actually, yes they are quite low, just 2 segments lit at best. Is this normal? No way could I ever get them clipping with either the drum machine or the Pod ! Also, the Pods 1/4" outputs are unbalanced ouputs, would that make a difference?

Smokehouse · Post by **Smokehouse** » Thu Mar 30, 2006 10:29 am

I'm guessing that your unit is functioning as it should. I (and I suspect that many of us here) can drive our Analog Inputs to clipping from various sources (like my synth), but on the other hand the mic inputs on the front panel I have a hard time clipping even at full gain.

I think you're all set, though. Case closed?

Bridgy · Post by **Bridgy** » Thu Mar 30, 2006 10:32 am

Are the outputs from your synth balanced and are you using balanced cables ?

mothra · Post by **mothra** » Thu Mar 30, 2006 11:57 am

Most synths arent balanced..

I dont think balanced/unbalanced cables should have that great of an effect on your level at all..

All my stuff is wired up to a Neutrik balanced patchbay in my home studio.
Balanced cables going from MOTU->Patchbay, but all my synths arent balanced so those are normal cables going from Patchbay->synths..

Ive never had a problem with output being too low unless it was from the synth itself.. I do wish for a gain knob like on a real mixer but sounds like yours is working fine, and its just the funny way MOTU decided to set it up.
Youll have to take a balance of the -10/+4 and boost switches to get the level you want it sounds like.

Bridgy · Post by **Bridgy** » Thu Mar 30, 2006 12:15 pm

I do believe that balanced does make a difference. If you think about the way a balanced setup works. The balanced cable carries two signals one of which is phase inverted. At the receiving end, these are passed through a difference amplifier effectively doubling the amplitude of the musical signal but zeroizing any noise spike (the noise would not have been phase inverted) which may have been picked up along the cable. If an unbalaced lead is used there is only one signal hence no doubling of the amplitude by the difference amp at the recieving end. So it must make a difference pluggung an unbalance source into a balanced input! or have I got this totally wrong? (it has been known !)

Smokehouse · Post by **Smokehouse** » Fri Mar 31, 2006 7:21 am

I'm with mothra. Unbalanced cables for pretty much everything in my home studio. But your logic that balanced lines would provide a relatively "hotter" signal makes sense.

Bridgy · Post by **Bridgy** » Fri Mar 31, 2006 7:21 am

Finally managed to get the right balanced leads to switch to the balanced outputs of the PODXT Pro. Man what a difference !!! No probs clipin' the inputs now

Thanks for all your um err "Input" guys