Clipping with thumping sound, but levels look normal (or even low)

Quad Cortex
1

I’m running into some weird intermittent clipping. But my levels are fairly conservative.

I even turned everything down in the path, including the input, output, as well as the blocks.

My CPU’s don’t appear to be overloaded - the CPU meter reads below 50%, and when I look at the DSP diagnotics, it doesn’t appear of the individual CPUs are much higher. They’re pretty well balanced.

Compared to some presets I’ve y’all building, mine are downright simple.

My typical preset includes…

ROW 1:

Adaptive gate (sometimes)

Cory Wong DI (used as comp)

Drive block (the stock XOTIC or BE-OD models with no tweaks)

Phase 95 (I think that’ what NDSP calls it), low mix, low speed.

V2 amp capture (my crunch and lead sound)

ROW 2: Another V2 amp capture for my cleans

ROW 3/4: TC2290 chorus, Cory Wong reverb, NDSP ambient reverb (just the slightest room ambience - always on), Cory Wong delay, and a Freeze >>> I can’t recall what’s on row 3 or 4.

It has been making random thump alongside the clipping indicator. Even after I turned everything down to a whisper level. Occasionally, the clipping will take off like a motorboat. THe only way to stop it is to remove blocks. But that seems to only work briefly.

My QC is mounted to a Metro 20 board 3M Dual-Lok, and my vents have free and open access to air flow. Power supply is CIOKS DC7 with Crux. But this only puts out 2A, where as the NSDP supply is 3A - supposedly the Cioks should be adequate, but I will double check to make sure it’s all setup correctly.

I just plugged into the Neural DSP supplied wall wart to see if it is more stable when it has access to a full 3A.

///

Has anyone dealt with this before? Anything else worth checking or trying?

2

Most likely from the compressor driving your signal too hard or distorting the signal from the amount of compression.

Could also be the gain staging you have within the preset driving certain blocks harder than you may think.

Also the CPU doesn’t need to hit 50% to be full if you’re using only row 1+2. I find it’s pretty full after 40%.

3

I’m certain it’s not the levels, even in the compressor - I turned everything down. Each block is barely passing a signal into the next block (or row).

And I’m using 3 rows (thought it was all 4, but just 3).

I’m currently leaning towards a power issue. DC7 with CRUX. I double checked to make crux was switched over to 12V. But I can’t keep my eye on it all night, so I have my DAW recording with my speakers turned up. If/when it happens, it’ll catch my attention.

My captures were probably a little hot, when I captured them. But they are also turned down drastically. Would the initial capture level influence any clipping behavior on the output like this?

4

Does it make this noise using a factory preset and with nothng plugged in but the OEM power supply, guitar and headphones?

5

That’s up next.

I let it run with the fully loaded V2 preset into my DAW for an hour

Then the same with V1 captures, for the next 15 minutes or so

Then need to pick a factory preset, for an hour - followed by someone’s do-it-all preset.

All of these are with the CIOKS DC7/CRUX though. But I haven’t heard any motorboating yet.

Depending on what the recorded audio files reveal, I’ll repeat the cycle with the QC’s power supply.

6

Well, I’m a little more than 4 hours into this experiment, and not a single thump/clip-indicator or motorboat using the CIOKS/CRUX. I will try again at rehearsal tomorrow. Very frustrating. But maybe something was loose in the power supply connections, and poking around re-seated it(?).