• We would like to remind our members that this is a privately owned, run and supported forum. You are here at the invitation and discretion of the owners. As such, rules and standards of conduct will be applied that help keep this forum functioning as the owners desire. These include, but are not limited to, removing content and even access to the forum.

    Please give yourself a refresher on the forum rules you agreed to follow when you signed up.

AX8 running out of DSP at gig but not during 4 days of testing??

Gene

Inspired
Hi, I built a preset during a few days for gigging at weddings. During the show we do not stop between songs as set list has been arranged to keep the audience dancing on the floor with no lull.
So, I built a preset with a few scenes. The grid had a compressor, drive, amp, pitch, cab, delay and reverb blocks.
The drive, amp, cab and delay blocks featured X/Y switching between scenes but I never change scenes during a song, I programmed the preset so that the scenes are more genre orientated by using scene controllers on the amp block input gain, so kinda clean, crunch and heavy sounds.
The X state of the amp block featured a Vox AC30 TB and in Y a USA Clean Pre. The CAB X a modified AC30 2x12 and Y a 4x12 USA type.

While setting up the preset I did extensive testing and the DSP meter was at 80%. Over a few days both setting up the preset and actually using it to practice for a gig everything was fine.

But get this:

I go to the wedding and during the second song on the set I see the reverb block flashing on/off in the AX8 screen indicating lack of resources and I saw a message stating that.
Needless to say I was bloody pisD OFF and had to make a preset very quickly in order to finish the gig.

Now, I don't get this but what is the point of going to the trouble of tweaking presets and keeping an eye on DSP usage only to go out gigging and all of a sudden running out of DSP on a preset I tested for 4 days during which time no sign of lack of DSP.

Anyone have any idea what could have caused this?
 

brokenvail

Fractal Fanatic
Modifiers can cause cpu spikes. I have a preset that every once in a while has the reverb go out. Many times I just switch scenes and come right back and it is fine. Every once in a while I swap presets and come right back and it is fixed
 

Gene

Inspired
The weird thing is the preset showed no signs of DSP shortage during 4 days of use including using the modifiers and DSP was at 80%
 

Ghost_of_Cain

Inspired
For me, it happens that preset stays around 80% when I do nothing, sometimes the usage fluctuates with modifier's source changes, but as soon as I start playing with different intensity - bam, the reverb goes off :)

It didn't bother me at all, lowering echo density does not hurt my ears so much.

Besides... I play such medieval and ugly sounds, that reverb on stage is most often something really redundant. Nice guy tweaking the house PA told me so... ;)
 

brokenvail

Fractal Fanatic
So you don't change scenes in a song? Do you just use IA's. Modifiers can cause CPU spikes that is why mine clears up even with just a quick scene change.
 
did you add any USB / MIDI devices during the gig that was not tested? I see the DSP consumption becomes heavier when USB or MIDI devices are connected to the AX8...
 

Gene

Inspired
So you don't change scenes in a song? Do you just use IA's. Modifiers can cause CPU spikes that is why mine clears up even with just a quick scene change.
Hi. no I use the guitar's volume pot a lot to add grind or clean up the amount of gain , in addition to the scene controller on the input drive. I find I like doing it the old fashioned way from the guitar pot as it is easier to change on the fly, I just like the option of altering drive both ways.

I forgot to mention I am using a volume block and controlling it with external 2, delay bypass mode is assigned to external 3 and amp bright switch is on external 4.

What I can't understand is I played with this for few days building it and practicing with it using all external switches and modifiers and not once did it show any signs of lack of DSP over about four days use, until that is the night of the bloody gig! LOL:confused:
 

chris

Legend!
What I can't understand is I played with this for few days building it and practicing with it using all external switches and modifiers and not once did it show any signs of lack of DSP over about four days use, until that is the night of the bloody gig! LOL:confused:
hard to say. i've used the AX8 for over 2 years, including heavy testing and haven't experienced that. i believe you, but something must have changed between practice and gigs. even something that may seem irrelevant could have done it, like adding a modifier, or finally assigning that pedal, etc. i know you said you used it with everything, but just putting some examples for discussion's sake.

again, hard to say. you may want to upload your preset here so people can examine it and see if anything stands out. though, it probably is the Input Gain modifier - calculations for that particular parameter are very intense apparently.
 

Gene

Inspired
hard to say. i've used the AX8 for over 2 years, including heavy testing and haven't experienced that. i believe you, but something must have changed between practice and gigs. even something that may seem irrelevant could have done it, like adding a modifier, or finally assigning that pedal, etc. i know you said you used it with everything, but just putting some examples for discussion's sake.

again, hard to say. you may want to upload your preset here so people can examine it and see if anything stands out. though, it probably is the Input Gain modifier - calculations for that particular parameter are very intense apparently.
Hi Chris, thanks for reply. One of the guys here mention something interesting that could be going on. It is very likely I was playing harder ( with more attack) during the actual performance than where I built and practiced with the preset, so that could be a change.
Everything else was the same though including the guitar used. I forgot to say in original post (but put it in a reply here later) that I had a volume block in the chain assigned to external 2 on expression pedal, delay block mode bypass was on external pedal 3 and the amp block bright switch on external 4, didn't use them much though and tested them all during the few days and it sounded lovely and got a very good range of sounds through the front end of a modified Fender Excelsior, all it really has is a volume knob!
I was trying to build a 'one preset does all' kinda thing and probably pusher it too hard. But, the DSP issue never manifested itself during testing.
Perhaps if I was playing with more attack might cause it, or even a problem with mains at the venue, we were running a lot of gear and 6 of us.

I'll get there I'm sure, probably something I'm doing wrong as I know they great units.
 

Gene

Inspired
What is a safe DSP limit for AX8 presets do you reckon? I'm probably pushing it too hard, I connected it up to AX8 edit and it sitting at 88% so must be too high then. When I use the external control it must be spiking it as you say but once I know that I will be kinder to the AX8 when building presets or take the Axe FX II XL instead.

Would say 75% DSP usage and no more be about right?
 

Gene

Inspired
Another difference was I had OUT 2 which was sending signal to the amp cranked higher, but it hardly that.
 

chris

Legend!
80% is a good place to aim, though you can squeeze up to 85% typically. processing audio (playing guitar) does use CPU so that's what you're allowing that 5% for to get to 90%, and then the rest is for the unit to actually function. these are all approximate numbers, of course.

again, the Input Trim modifier can spike CPU usage very high depending on the particular amp model chosen. AX8-Edit (usb connection) also increases CPU slightly.

also, keep in mind that just because Reverb was disabled, it was only disabled for that specific instant. if you changed Scenes, it would recalculate and possibly allow the Reverb block to be enabled. it all is real-time, and depends on exactly what's going on in the preset at that moment.

amount of level coming out of Out 1 or Out 2 wouldn't affect it. i'm pretty sure it's the Input Trim modifier and something you did differently by chance.
 

Gene

Inspired
80% is a good place to aim, though you can squeeze up to 85% typically. processing audio (playing guitar) does use CPU so that's what you're allowing that 5% for to get to 90%, and then the rest is for the unit to actually function. these are all approximate numbers, of course.

again, the Input Trim modifier can spike CPU usage very high depending on the particular amp model chosen. AX8-Edit (usb connection) also increases CPU slightly.

also, keep in mind that just because Reverb was disabled, it was only disabled for that specific instant. if you changed Scenes, it would recalculate and possibly allow the Reverb block to be enabled. it all is real-time, and depends on exactly what's going on in the preset at that moment.

amount of level coming out of Out 1 or Out 2 wouldn't affect it. i'm pretty sure it's the Input Trim modifier and something you did differently by chance.
Ok, thanks, good to know where to aim for. I will change the input gain modifier to input trim and see if I get a change for the better, if not I'll use guitar knob, doesn't bother me as I used to that anyway so not an issue for me.
 

2112

Fractal Fanatic
If all else fails take the cab and reverb level down to normal and decrease the reverb density. Negligible differences when heard in a mix IMO.
 

Gene

Inspired
If all else fails take the cab and reverb level down to normal and decrease the reverb density. Negligible differences when heard in a mix IMO.
Hi, yeah might do that and bring the DSP down. It’s a good preset
 
Top Bottom