AJA IOLA input/output issue

[Ken Summerall]

Jamibo,

Plugging line level outputs into the mic input of a mixer is going to give you bad results unless you have some way of padding that hot line level signal. Give us alittle more info and we might be able to help more. What kind of mixer is it? Are you sure that the output on the amp is line level? Is the mixer self-powered (does it have an amp built in)? If it is then you will need to use an Aux out, or something that is not amplified. Give us all the info you can and we will try to help.

Ken Summerall
Wellwater Productions

[Jason Boucher]

That is what I suspected. The mixer I got is a 12 channel Mackie (model# escapes me). It is powered, so obviously the amp output (Fender Cyber Twin) is line level and the mixer input is mic level.

I’ll check it out and post my results. Thanks Ken!

Jason

[Ed Dooley]

The Mackie 1202 (I think it’s their only 12 channel mixer) has line level *and* mic level inputs. So a guitar,
for example should go into a line level (1/4″ TRS plug). Line level means a signal between -10dBu and +30dBu
(mic level is below -30dBu). The input on an AJA IOLA is +24dBu, so you should be OK.
Ed

[Jason Boucher]

That is what I figured. Thanks for the info. But now that raises another question…

I have the XLR outputs of my IO La (Ch 1&2) going into the XLR ins of the mixer… shouldn’t the output of FCP through the firewire through the IOLA and into the mixer be line level? I have them hooked up to the mic in XLRs and it doesn’t sound distorted, though the level is higher. (ie: -20dB tone out of FCP peaks through the mixer about 1/2 way up the sliders – does that make any sense?)

[Ed Dooley]

Hmmm, not sure (I’m not a super audio expert). The Mackie has gain on the 4 Mic inputs, could you possibly have the gain
knobs turned up on the Mackie mic inputs from the guitar, but not on the mic inputs from the IOLA (coming from FCP)? The levels
should match pretty closely.
Your guitar into the Mackie XLRs is+14dBu, the output from the Mackie to the IOLA (to the computer) using the Main Outs is +28dBu,
the IOLA I/O is +24dBu, and the Mic inputs of the IOLA signal (from the computer) is a +24dBu signal going into a +14dBu connection.
I use both XLR-XLR and XLR-TRS cables to connect decks through a Mackie and both work fine. I don’t know much about guitar amps,
but can you send a signal from the preamp to the Mackie, before the amp, to keep the level reasonable?
Ed

[jamibo] “I have the XLR outputs of my IO La (Ch 1&2) going into the XLR ins of the mixer… shouldn’t the output of FCP through the firewire through the IOLA and into the mixer be line level? I have them hooked up to the mic in XLRs and it doesn’t sound distorted, though the level is higher. (ie: -20dB tone out of FCP peaks through the mixer about 1/2 way up the sliders – does that make any sense?)”

[Jason Boucher]

Wow… and you call yourself NOT a super audio expert!! Wonder what that makes me?? LOL!

Well armed with that, I’ll have to check it out. I’m not one to complain about being busy, but I quite honestly haven’t had much time on my home system in over a month. But as soon as I do, I’ll post my results!

Thanks Ed and Ken for your input. This forum is an invaluable resource. I do appreciate it.

Jason

Mackie mixer is DFX-12… not sure if that means anything, but it was surely not their best rig, though it seems to be exactly what I need… if only its operator would learn to use it!!

[Ken Summerall]

Jamibo,

Also be sure that you have Phantom Power turned off if you have the outputs from the IO LA going into your Mackie. The IoLA cannot handle phantom powered mic pres and will eventually burn up. You shouldn’t need Phantom power anyway unless you have a condenser mic that you are using.

BTW, Ed has given you some great advice, keep listening to him, he obviously knows what he is talking about.

Ken Summerall
Wellwater Productions, Inc.
“A non-profit production company specializing in media with a mission.”

[Ed Dooley]

I just saw the specs for the DFX-12 online. They’re a little different than the 1202VFX:
Maximum levels for Mic input (XLRs) is -22dBu, all other inputs are +20dBu, main
outputs are +20dBu, all others are +4dBu. Notice the Mic in level of your DFX is very different
than the 1202 I have (+14dBu). I never asked, why do you have an XLR cable running from
your guitar amp anyway instead of a 1/4″ TRS cable? Are you running it through a direct box or something? I don’t know of any guitar amps with XLR out (but admittedly, I don’t know a lot about guitar amps!)
HTH,
Ed

[Jason Boucher]

This amp has a pair of stereo XLR outs, they’re line level out. My other one has 1/4″… I’ve ordered XLR to 1/4″ cables, so that should solve all problems.

Thanks again!

[Jason Boucher]

OK… I tried something different today and now I’m very confused. I plugged my acoustic guitar with small preamp to the line-in input on the mixer and tried to record into garageband. The signal was still distorted and had like a delay/echo/feedback thing going on. I then switched to MIC level input and got the same result.

I have had no issue with the mixer/AJA set up with FCP, Motion or Soundtrack, but I’m having quite a time trying to get a real instrument to record. What could I be doing wrong? Feeling a little stupid at this point, but it’s not making any sense to me.