Plugin sample rate

spantini

COO of me, inc.
First, I'd like to post this L I N K B A C K to a related sticky thread here in the Digital Recording Forum.

I was setting up my new Amplitube 4 - Fender Collection this afternoon and it's default sample rate was 48kHz. I've been using 44.1 in Reaper (default) with no problems so I set Amplitube to match Reaper.

I was jamming with a '65 Twin Reverb (headphones) and heard a couple of quick, electronic noise 'clicks' and simultaneous audio dropouts - then everything resumed without problem.

My first thought was line noise from my A/C coming on at that moment, but that's not been a problem with anything I've been running up to this point. Now I'm wondering if maybe this Amplitube 4 program needs to sample at it's factory preset default 48kHz.. or even if that matters at all as far as this noise goes.

I can only wait for a repeat of the situation, then switch to 48kHz and see if it repeats again.

I was running it standalone, then plugin - I didn't take note of which one had the glitch.
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p.s. - - My chain was : Tuner - Amp - Cab - Mic

I didn't have a bunch of stomp boxes and rack mounts going.


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Whilst on walkabout, I tripped across this site with some good info ...
Depends what you mean by 'good'. "...for online distribution, go for 24 bit to capture the true essence of the dynamics in your music." That is incorrect, 24 bits captures no more dynamics than 16 bit.
 
Depends what you mean by 'good'. "...for online distribution, go for 24 bit to capture the true essence of the dynamics in your music." That is incorrect, 24 bits captures no more dynamics than 16 bit.
Really? It was my understanding that the extra depth lowered the noise floor so that a wider dynamic range could be captured.
 
I may be off base but I would guess that a click and dropout type glitch would be more likely to be an AD or DA related issue, or something interrupting the I/O through the interface connection. Usually sample rate issues result in weird/slow/fast audio that doesn't appear then disappear. USB problems can cause this too.
 
So I got side-tracked by the previous unrelated comment. Your sample rate, especially lowering it, shouldn't affect the VST, assuming all your pieces are configured correctly. But, the kind of noise you describe does suggest a data hiccup. No place to put new data coming in because the previous stuff is not moved out of the way, or (more likely) a fetch for the next block of data gets nothing or garbage because the processing of data was not completed in time to fill the buffer.

If you're monitoring VSTs realtime, you will start to find out which ones are efficient, at least in relation to your system, and which are not. Make sure you're using just one when you try to isolate the problem, and then get to a reproducible scenario. Next, start changing things like buffer size, and, sure, even sample rate.

The signal chain in front of the interface doesn't matter, unless what you're describing is the simulated chain!
 
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If you're monitoring VSTs realtime, you will start to find out which ones are efficient, at least in relation to your system, and which are not. Make sure you're using just one when you try to isolate the problem, and then get to a reproducible scenario. Next, start changing things like buffer size, and, sure, even sample rate.

The signal chain in front of the interface doesn't matter, unless what you're describing is the simulated chain!

The signal chain I posted earlier was all within the Amplitube plugin VST.
 
Really? It was my understanding that the extra depth lowered the noise floor so that a wider dynamic range could be captured.

Sort of true. In a practical sense, any digital noise or distortion from 16 bit audio is barely audible. 16 bit dynamic range is actually pretty good.

The real benefit of 24 bit audio is if you're going to process it in a DAW. The extra resolution makes it less vulnerable to breaking because of math errors. 16 bit ended up being the bare minimum for full range. It was almost going to be 18 bits before CDs came out but the comittee wanted the extra minutes of run time on compact discs.
 
Really? It was my understanding that the extra depth lowered the noise floor so that a wider dynamic range could be captured.

Technically yes, but since the average pop song has a dynamic range of 12db, an extra 48db of dynamic range on top of the 96db that 16 bits provides is pointless.
 
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