None of them are SPICE because of numerous reasons.
So initially your list disagrees with your assertion (where they use -6 dB reference) and you go on to argue that one particular bit of software uses one particular value, therefore another must? Do you have any hard evidence to back this up?
Again, I find it extremely unlikely any software would use 0 dB as a reference although one or two may do so.
"They are all basically SPICE" is pure 100% nonsense.
Input Voltage/Gain Calibration for Guitar Plugins
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- KVRAF
- 12615 posts since 7 Dec, 2004
Free plug-ins for Windows, MacOS and Linux. Xhip Synthesizer v8.0 and Xhip Effects Bundle v6.7.
The coder's credo: We believe our work is neither clever nor difficult; it is done because we thought it would be easy.
Work less; get more done.
The coder's credo: We believe our work is neither clever nor difficult; it is done because we thought it would be easy.
Work less; get more done.
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- KVRist
- Topic Starter
- 44 posts since 7 Apr, 2017
WRONG, most of them are SPICE based then directly codded to C++ for real time interpretation and easier transfer between systems.aciddose wrote:None of them are SPICE because of numerous reasons.
Where do you get the -6db reference from?
Have you mistaken 2VPP with -6db?
2vpp (peak to peak) is 1v peak -> which should be 0.0dbFS.
Or 0.707v AC RMS which still should be 0.0dbFS for a pure sinus wave (not guitar signal).
You can't simply play a note on your guitar and adjust till it's -3db in your DAW, this does not take into consideration that every guitar pickup outputs a different voltage which is exactly why we want to calibrate.
We don't want to make all guitars equal by peaking the red light with hard strumming like the manuals of commercial amp sims VST suggest.
Once again, a Telecaster is 60 times less voltage than an EMG equipped guitar, we want to preserve that difference.
Also, If you don't like my theory please move on, you don't have to take a huge dump on this thread by calling my every post nonsense and stupid, and I don't feel the need to provide your argumentative nature with any further proof beyond what I had already given.
Take a break and let other people participate.
Thanks
Last edited by Ilya-v on Wed Apr 12, 2017 9:11 am, edited 1 time in total.
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- KVRer
- 23 posts since 8 Apr, 2017
Some testing:
Ilya-v: peak without any gain setting inside the daw is at -13 with the gain knob on hi-z interface set at the minimum
aciddose: peak without gain setting inside the daw is at -3.2 with the gain knob on hi-z interface set at noon which is just before the interface clipping (which is green or red like on and off)
Ilya-v: peak without any gain setting inside the daw is at -13 with the gain knob on hi-z interface set at the minimum
aciddose: peak without gain setting inside the daw is at -3.2 with the gain knob on hi-z interface set at noon which is just before the interface clipping (which is green or red like on and off)
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- KVRist
- Topic Starter
- 44 posts since 7 Apr, 2017
According to the specs you gave me where +9dBu is maximum input before clipping with the gain trim at minimum, you need to boost by 9.8db in your DAW.jacotzen wrote:Some testing:
Ilya-v: peak without any gain setting inside the daw is at -13 with the gain knob on hi-z interface set at the minimum.
This will get you close enough without actually owning a function generator, if of course the specs are accurate.
By using the gain knob on your audio interface you are changing how hot the pickups on your guitar are.
The point of calibration is to completely eliminate the guitar and how hard you play out of the equation.
What guitar is it?
Last edited by Ilya-v on Sat Apr 08, 2017 1:25 pm, edited 1 time in total.
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- KVRer
- 23 posts since 8 Apr, 2017
Ilya-v: applying +6.4db by a gain plugin before amplitube and setting inside amplitube every in and out at 0 the resulting peak is at -2.8
aciddose: applying no gain plugin before amplitube (since the source was just peaking at -3) and setting inside amplitube every in and out at 0 the resulting peak is at -1.9
aciddose: applying no gain plugin before amplitube (since the source was just peaking at -3) and setting inside amplitube every in and out at 0 the resulting peak is at -1.9
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- KVRist
- Topic Starter
- 44 posts since 7 Apr, 2017
Some quick calculations for typical audio interface Instrument High-Z input values:
+4dBu headroom (1.736V Peak) with Gain trim at minimum, boost by 4.79db.
+5dBu headroom (1.948V Peak) with Gain trim at minimum, boost by 5.79db.
+6dBu headroom (2.185V Peak) with Gain trim at minimum, boost by 6.79db.
+7dBu headroom (2.452V Peak) with Gain trim at minimum, boost by 7.79db.
+8dBu (2.751V Peak) -> boost 8.79db
+9dBu (3.087V Peak) -> boost 9.79db.
+10dBu (3.464V Peak) -> boost 10.79db.
The higher headroom the audio interface has the more we have to boost it because real world voltage will be lower on the digital dbFS scale.
My Focusrite Saffire speced at +8dBu and I had to boost 8db, just according to calculation.
EDIT:
@jacotzen,
I had a small miscalculation with the 6.4db value I gave you previously.
Here's how to properly calculate yourself:
1. Use this link to convert dBu to Vpp: http://www.sengpielaudio.com/calculator-db-volt.htm
2. Divid the volts (p-p) by 2 to get Peak value.
3. Use this link to calculate how much difference in db between 1V and the Peak value: http://www.sengpielaudio.com/calculator-gainloss.htm
+4dBu headroom (1.736V Peak) with Gain trim at minimum, boost by 4.79db.
+5dBu headroom (1.948V Peak) with Gain trim at minimum, boost by 5.79db.
+6dBu headroom (2.185V Peak) with Gain trim at minimum, boost by 6.79db.
+7dBu headroom (2.452V Peak) with Gain trim at minimum, boost by 7.79db.
+8dBu (2.751V Peak) -> boost 8.79db
+9dBu (3.087V Peak) -> boost 9.79db.
+10dBu (3.464V Peak) -> boost 10.79db.
The higher headroom the audio interface has the more we have to boost it because real world voltage will be lower on the digital dbFS scale.
My Focusrite Saffire speced at +8dBu and I had to boost 8db, just according to calculation.
EDIT:
@jacotzen,
I had a small miscalculation with the 6.4db value I gave you previously.
Here's how to properly calculate yourself:
1. Use this link to convert dBu to Vpp: http://www.sengpielaudio.com/calculator-db-volt.htm
2. Divid the volts (p-p) by 2 to get Peak value.
3. Use this link to calculate how much difference in db between 1V and the Peak value: http://www.sengpielaudio.com/calculator-gainloss.htm
Last edited by Ilya-v on Sat Apr 08, 2017 3:44 pm, edited 1 time in total.
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- KVRer
- 23 posts since 8 Apr, 2017
This is the resulting audio with Ilya-v (first riff) settings and aciddose (second riff) https://www.dropbox.com/s/ds4zy3tedy76l0h/test.mp3?dl=0
what's strange is that actually the metronome is audible inside the recording and you can easily hear some feedback inside even if everywhere the leds are on green
Ilya-v: your settings produce more noise as you can easily compare
to me both sound no good, and I have the feeling that, still, the gain structure is bad
what's strange is that actually the metronome is audible inside the recording and you can easily hear some feedback inside even if everywhere the leds are on green
Ilya-v: your settings produce more noise as you can easily compare
to me both sound no good, and I have the feeling that, still, the gain structure is bad
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- KVRist
- Topic Starter
- 44 posts since 7 Apr, 2017
Something is definitely wrong, Amplitube should not be that noisy.jacotzen wrote: what's strange is that actually the metronome is audible inside the recording and you can easily hear some feedback inside even if everywhere the leds are on green
Your input signal picks up some of the output signal, maybe through ground, but that's another topic.
Obviously, we boost the noise floor along with the signal, but the amp sim does that anyway.jacotzen wrote: Ilya-v: your settings produce more noise as you can easily compare
It may be that the Gain pot on the audio interface adds gain without raising the noise floor so it will be cleaner.
The Focusrite raises the noise floor even if I move the gain pot slightly.
You can calibrate with the gain pot if it's quieter and a function generator, but you should be careful not touch the gain pot after calibration.
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- KVRer
- 23 posts since 8 Apr, 2017
:/ I should run a test with another sound card then :/ I'm getting mad!!!
Btw this is from NRR-1 Ignite Amp manual:
"So, the first thing you need to make sure of, is to never clip the AD converter (if you are clipping it, the clipping led indicator featured in most audio interface will light on, warning you that your input signal is too hot, so you need to lower the preamplifier control until the problem disappears).
On the other hand, an important thing to keep in mind, is that the higher the input signal (within the above mentioned headroom limit), the more accurate the AD convertion will be, keeping also the signal-to-noise ratio at the higher possible value. This means that, in order to get the best out of your sound-card, you need to keep the input signal as high as possible right before reaching the clipping threshold.
Ok, cool story, but when does the input level control comes into play? Once your signal is converted to digital, it will be represented as a series of numbers that you can see as voltage values. These voltages can have a maximum and minimum value of 1.0 and -1.0 respectively. Supposing your input signal is peaking at its higher possible value right before the clipping threshold of the converter, it will be represented as 1.0 inside your host and the NRR-1 will react to it like if you're sending a 1.0V signal to its input stage.
Why is it so important to know these details? Because if your guitar pickup has a maximum output voltage higher than 1V (or 2V peak-to-peak), like many modern active pickups have, you'll need to adjust the input signal that's being sent to NRR-1. That's where the Input Level control comes into play. You need to tweak it to compensate the voltage scaling/normalization made by your AD converter.
Every tick you see under the Input Level slider, represents a variation of 0.25. For example, if your pickup has a maximum output of 1.5V (so 3V peak-to-peak), you'll need to set the slider at the 2nd tick moving it to the right. By doing this, your input will be multiplied by 1.5 (1 + 0.25 + 0.25 = 1.5), so NRR-1 will not be fed with a 1.0V maximum signal, instead, it'll get a 1.0V x 1.5 = 1.5V maximum signal, which is the correct value to match your pickup specifications.
If you are using a single coil, instead, and its maximum output value is, let's say, 0.5V, you'll need to lower the input level by moving the slider to the second tick to the left. This will make NRR-1 react like the input signal is 0.5V, or 1V x 0.5 (1 – 0.25 – 0.25 = 0.5).
Remember that the sound-card input level is meant to be always set so that you use the full AD converter headroom. Signal level adjustments, to pair NRR-1 with your guitar pickups, need to be made after the AD conversion, using the Input Level control."
Btw this is from NRR-1 Ignite Amp manual:
"So, the first thing you need to make sure of, is to never clip the AD converter (if you are clipping it, the clipping led indicator featured in most audio interface will light on, warning you that your input signal is too hot, so you need to lower the preamplifier control until the problem disappears).
On the other hand, an important thing to keep in mind, is that the higher the input signal (within the above mentioned headroom limit), the more accurate the AD convertion will be, keeping also the signal-to-noise ratio at the higher possible value. This means that, in order to get the best out of your sound-card, you need to keep the input signal as high as possible right before reaching the clipping threshold.
Ok, cool story, but when does the input level control comes into play? Once your signal is converted to digital, it will be represented as a series of numbers that you can see as voltage values. These voltages can have a maximum and minimum value of 1.0 and -1.0 respectively. Supposing your input signal is peaking at its higher possible value right before the clipping threshold of the converter, it will be represented as 1.0 inside your host and the NRR-1 will react to it like if you're sending a 1.0V signal to its input stage.
Why is it so important to know these details? Because if your guitar pickup has a maximum output voltage higher than 1V (or 2V peak-to-peak), like many modern active pickups have, you'll need to adjust the input signal that's being sent to NRR-1. That's where the Input Level control comes into play. You need to tweak it to compensate the voltage scaling/normalization made by your AD converter.
Every tick you see under the Input Level slider, represents a variation of 0.25. For example, if your pickup has a maximum output of 1.5V (so 3V peak-to-peak), you'll need to set the slider at the 2nd tick moving it to the right. By doing this, your input will be multiplied by 1.5 (1 + 0.25 + 0.25 = 1.5), so NRR-1 will not be fed with a 1.0V maximum signal, instead, it'll get a 1.0V x 1.5 = 1.5V maximum signal, which is the correct value to match your pickup specifications.
If you are using a single coil, instead, and its maximum output value is, let's say, 0.5V, you'll need to lower the input level by moving the slider to the second tick to the left. This will make NRR-1 react like the input signal is 0.5V, or 1V x 0.5 (1 – 0.25 – 0.25 = 0.5).
Remember that the sound-card input level is meant to be always set so that you use the full AD converter headroom. Signal level adjustments, to pair NRR-1 with your guitar pickups, need to be made after the AD conversion, using the Input Level control."
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- KVRer
- 23 posts since 8 Apr, 2017
This is the only info on gain staging from the Amplitube 4 manual:
"Set your audio device’s input gain so that AmpliTube’s INPUT LEVEL meter is starting to go into the red, then back off just a touch.
The AmpliTube 4 OUTPUT LEVEL is controlled by the MASTER knob. Try to keep the OUTPUT LEVEL just below the point of clipping. If possible, try to accomplish this in AmpliTube’s signal path by using proper gain staging and the Cab Room mixer. As a last resort, the MASTER knob provides a quick fix for output level woes.
Pro Tip: if you find that clean tones are too quiet and lead tones are too loud across the board, this probably means that the input gain on your audio device is set too low. Some presets may still have too much or too little bite for your particular instrument. Adjust the INPUT knob on these presets for your guitar, then resave them."
"Set your audio device’s input gain so that AmpliTube’s INPUT LEVEL meter is starting to go into the red, then back off just a touch.
The AmpliTube 4 OUTPUT LEVEL is controlled by the MASTER knob. Try to keep the OUTPUT LEVEL just below the point of clipping. If possible, try to accomplish this in AmpliTube’s signal path by using proper gain staging and the Cab Room mixer. As a last resort, the MASTER knob provides a quick fix for output level woes.
Pro Tip: if you find that clean tones are too quiet and lead tones are too loud across the board, this probably means that the input gain on your audio device is set too low. Some presets may still have too much or too little bite for your particular instrument. Adjust the INPUT knob on these presets for your guitar, then resave them."
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- KVRist
- Topic Starter
- 44 posts since 7 Apr, 2017
Yet again, if you apply this Amplitube method you will have a Telecaster that is equally as hot as an EMG guitar.
How can a company that prides itself having "hyper-realistic" simulation can actually instruct this?
Talking about nonsense, this instruction by Amplitube is it.
Meanwhile, a pretty close estimation without a function generator would be to take the audio interface Spec of the High-Z Instrument Maximum Input in +dBu and boost accordingly.
That is, if the audio interface has this spec.
How can a company that prides itself having "hyper-realistic" simulation can actually instruct this?
Talking about nonsense, this instruction by Amplitube is it.
Meanwhile, a pretty close estimation without a function generator would be to take the audio interface Spec of the High-Z Instrument Maximum Input in +dBu and boost accordingly.
That is, if the audio interface has this spec.
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- KVRer
- 23 posts since 8 Apr, 2017
Actually my massive noise floor is caused by the stomp box with those settings (don't look extremely loud to me), if I use the beautiful tse r47 is even worst... yet, the function 'selected module volume' on amplitube seems somethings esoteric...