Motu Hybrid Guitar volume weirdness

[OldMacTech]

I use a Mkiii Hybrid on AC power with Mac Mini Core i5 and Logic Pro X.
I have a guitar amp with XLR outs that I sometimes use for direct recording. Today I was recording on Mic 2 input and the Gtr volume seemed low coming off the Motu. I give the gain a slight twist and it was like the volume doubled all of a sudden. I went ahead a played a few bars and shortly the volumed dropped again. Touched the gain and it went back up. Did this a few times and finally on the last pass it made it it almost to the end of the track, made a funny noise and the volume dropped completely. As far as I know, it's only on channel two gain but haven't tried Channel 1.

I have a couple of theories for tomorrow wanted to see if anyone had had this problem.
Maybe a dirty pot on the Mic 2 gain?
Bad XLR cable?
Is it possible I had the volume to high and it cut itself off to save the circuit?

Didn't notice the DAW gain reading on the tracks.

Any help would be appreciated.

JB

[4stripes]

What is the model of the guitar amp? That would help.

There's no such thing as 'saving the circuit' volume protection.

It's probably the output of your amp.

[OldMacTech]

Hughes & Kettner TubeMeister 5 - 5-Watt Tube Head

Love the sound of the Amp with Gibson Humbuckers, not so much with American Telecaster.

Thanks.

[4stripes]

You should not connect your amp XLR output to a mic preamp. It has too high impedance. Use an XLR>TRS to go into a MOTU line in. Read the manual of your amp:

RED BOX
The RED BOX, as invented by Hughes & Kettner,
has now been for years the industry standard
for guitar DI boxes with speaker emulation. It
converts the speaker line out signal, which in the
TUBEMEISTER 5 is generated between the tube
power-amp and the POWER SOAK, to a balanced,
frequency corrected signal. If this signal is rendered
through a PA or studio monitors, the acoustic
impression will match that of a guitar amplifier.
A microphone cable serves as a connection to a
mixing desk. In this case, the XLR connector input
on the mixing desk MUST be switched to line
level. If the mixing desk is not equipped with XLR
connector inputs, or if these cannot be switched to
line level, you may purchase a suitable XLR to 1/4"
jack adaptor.
The signal level directly depends on the MASTER
settings; but it is independent of the POWER SOAK
settings.

[OldMacTech]

Thanks, got right by me. As soon as I get a chance I will look for an adaptor. Until then, better stay away from the direct cabling.

Thanks.

JB

[mikehalloran]

Thanks, got right by me. As soon as I get a chance I will look for an adaptor. Until then, better stay away from the direct cabling.

Thanks.

JB

Markertek has great prices on adapters and adapter cables if you can't find what you want sourced locally.
http://www.markertek.com/?gclid=CI31i5W ... fgodfXYA3A

For many years, they were the only source for pre-wired Switchcraft XLR-TRS adapters. Everyone else made you solder the damned things after you received them (You want what???).

[OldMacTech]

Thanks. Thought I had it licked but the Mic cable I have with 1/4" is TRS and not mono. Got sound but also a lot of noise.

Gonna quit while ahead (sort of).

Thanks for the link-will look on Monoprice also.

JB

[4stripes]

It says its a balanced output, so TRS ("stereo") is what you need, as mentioned before. From the manual: "The signal level directly depends on the MASTER settings; but it is independent of the POWER SOAK settings."

You might have your master settings too high or low. Try adjusting that.

Again, all there in the manual: RED BOX Out XLR, balanced, 1,360Ω, max +3 dBV
That's +5 dBu into a proper high impedance line input. The RED BOX output is much higher imp than normal line outs, therefore it's not appropriate to use a mic preamp, because mic preamps are lower impedance than line inputs, and the rule is >10x input imp.

[OldMacTech]

Got it to work with a Mic Cable I had - XLR to TRS-
Initially was really distorted, sprayed contact cleaner in the XLR females, rebooted the computer and the a MOTU- voila. Works fine.

Thanks,

Jb