Attenuator on audio output

#1

As it is sometimes hard to find out how to adjust the volume on a patch from someone else, I would suggest a default attenuator on the audio out objects. At least you can then be sure you start with a low volume. (ouch my ears, I just tested my axoloti, freshly arrived today, with headphones...)

#2

Yeah, you have to be 'careful' with gain levels hence the warning on the sheet in the box...

personally, I always have an external volume control, and turn it down... especially when you start writing your own patches, its possible if you get the wiring wrong, you might get some 'unusual' surprises smile (same goes for patches you get from others)

but you make a very good point,
its a good idea, the issue is there may be many Audio Output objects, and some of them may be in sub patches, so its quite possible you would still 'miss' some.

what we are thinking is perhaps a global preference, to limit volumes, that can be controlled from the GUI/ midi CC.
(there is already an audio/outconfig which might be worth trying on patches....)

of course, we will never get away from the fact patches are unlikely to be level matched, so some care is always needed.
(in fairness, i have the same issue with some patches I have for my other external synth)

BTW: let us know if there are any demos etc that in particular are loud (compared to others), perhaps we can take their gain levels back a bit.

#3

There is the "audio/outconfig" object to control headphone output level - but can only be adjusted at patch start.
This controls analog gain for the headphone output, line out level is independent, and you do not lose resolution if that would be a concern.
This setting is persistent until you powercycle the board (or the board does an automatic reboot when it crashed), so this is not a very safe solution.

Did you connect your headphones to the line out or the headphone out?

Yeah a global preference will be added in flash memory in the future.

#4

I tested with my KVR headphones which are quite sensitive using the headphone jack. Normally I would run it through my mixer, with the faders down. Still a global UI settable master volume would be a great addition!

#5

Is there an option for digitally controlled analogue gain on the line out as well? Or does the codec not support that? At least, I didn't see anything in the factory objects when I last looked.
When just messing around, I tend to run my axoloti into a little solid state practice guitar amp. I have to stick a *c on the output otherwise the amp's input can be severely overdriven by the axo, but obviously the *c is losing me a bunch of resolution.

#6

the codec supports a coarse grained (like headphones) gain control for line output, we could add this to outconfig.
(till then you could set in your own object)

#7

Ah yeah, that's precisely the kind of thing I meant. I guess it wouldn't be hard to adapt it from the headphones one? It'd just be setting different registers I suppose.

#8

The codec indeed supports digitally controlled analogue gain on the line output too, but so far not exposed in any object. I'm not sure if it will increase the resulting audio quality significantly compared to digital scaling, the codec gets 24 bits of data. Yes just a matter of setting a different register, but take care some bits in R31 and R32 have other meanings than volume, check the ADAU1361 datasheet for details.

#9

Thanks for the pointers. It's not like I felt that I was hearing a problem with using digital attenuation, I guess it just makes sense to try and use the analogue attenuation if the option is there.

#10

Sure, please tell if you notice any improvement!

#11

I doubt I will! The only times I've heard any quantisation noise has been when using delays (am I correct in thinking they're only 16-bit?). 24-bit is so much, even if I half the volume digitally that's still 23-bit!

#12

I hope this thread is going to lead to live headphone/main out master volume controls :slight_smile:

I have just come across this same issue, got my axoloti today, testing through headphones, tried to heed the warnings to turn it down, couldn't find a headphone object :cold_sweat:

I think It would be worth putting something in the installation instructions about adding an audio/outconfig object to your patch if you plan to use headphones for testing.