No Audio in Triggering Gate?

[sparki]

@bruno
My request is older than a week, but no hassle please

My soundcard is a focusrite saffire 6, my specs are listed in my signature...

i maxed everything, even with compressors and put in everything i got, but it is just not possible to get the MB triggered by a clean signal.
so the official anwser is right now that a common audio interface dont have enough gain to trigger the mb, and i have buy a preamp? wtf?

[Bruno@arturia]

here are your audio interface output specs

Analogue Audio Outputs 1-2 (¼" TRS)

    Electronically Balanced Outputs
    Maximum Output Level (0dBFS): +9 dBu
    THD+N: 0.0025% (0 dBFS input, 20Hz/22kHz bandpass filter)

Analogue Audio Outputs 1-4 (RCA phono)

    Unbalanced Outputs
    Maximum output level (0dBFS): -3.5 dBu
    THD+N: 0.03% (0 dBFS input, 20Hz/20kHz bandpass filter)

Headphone Outputs

    Frequency Response: 20Hz-20KHz +/- 0.1 dB
    SNR (A-weighted): 103 dB
    Dynamic Range: 103 dB
    Maximum Output into 32R: +3 dBu (-1.4 dBV)
    Power into 32R: 24 mW
    Output Impedance: < 7 Ohms
    Load Impedance: > 24 Ohms

As you can see, to get the hottest out signal you should use TRS analog out, not headphone, or RCA.

so the official anwser is right now that a common audio interface dont have enough gain to trigger the mb, and i have buy a preamp? wtf?

In best conditions you audio output is +9dBu, for example my Motu 828 is +18dBu, the other cheap alesis MultiMix4 I have is +19dBu
That is a huge difference..... both are trigging fine
On the other side I just tried an M-audio firewire audiophile that outputs 9dBu, using this one it was indeed more difficult (but still possible) to make it trig.

So the official answer is that some common audio interfaces may need a preamp to properly trig the gate from audio input.

I know it not what your wanted to ear, but I have not solution on this point, except, as I told earlier changing a resistor.
This function has probably not been tested enough before validation of the design... sorry about that.

one last thing you should know, the ability to trig is depending on the audio signal you are using, indeed before the trig circuit, the audio is averaged (to have a clean trig, without bounces). So that means that you should not use "short" signals, such as a very dry snare or metronome click, or claps. The longest the input signal is, the better you will get a proper trig. For example a long decay, well compressed kick will do the job much better than a rim-shot.

I hope it will help anyway.

[grier]

For both it possible do increase audio In gain by changing 1 resistor value. If you are interested I may tell you which one, and which new value to use. But keep in mind it's 0603 SMD components, so very small. You should be either used to do it either ask someone that is. And of course it will void your warranty.

Bruno, I would be very interested to know this for future reference.  I definitely cannot do it now, but I may learn how and if I get comfortable doing it I would be very, very interested to have this information documented so I could go ahead and make the swap in the future at some point (this may be 5-10 years down the road!!).  It would be really great to have a higher audio in, and I know if I learn a little bit about how to do this, I probably would want to change it.

Can you make the information available here, or PM me at least so I can keep it archived in my own files?

Hi Bruno, I second this ... Could you please share with me (via email or PM) the resistor value to use?

Also, I'm considering installing a small toggle switch on the back panel, with one leg going to the unmodified "audio in" circuit, the other routing the "audio in" through the new resistor. What do you think?

If this works, and there's enough interest, I'd be happy to write the whole procedure up and include diagrams or photos.

[Bruno@arturia]

Hi,
 that would nice from you, I'll send info to you as soon as I have a bit of time. But keep in mind that it will void your warranty....