I've owned two. One I bought last year while you were seemingly taking a break from the forum. I just sold it. I've described exactly what I liked about it and what I didn't, and where my first experience differed from my latest one. Feel free to go look that up.
First of all, my valve amps are quieter when I plug my guitar into it directly, with no effects in the signal path. This is completely normal and obvious, and is to be expected. So it isn't the valve amp at fault.
Noise definitely exists in the analog domain. No question. But that isn't the noise that is the problem here; it isn't the root cause.
Now. Noise floor in digital systems is incredibly difficult to deal with. All you can do is your best. You'll never get rid of it 100% because the physics simply does not allow for it. But there are some things that you should try to do at the electrical engineering level, in order to give the system as a whole the best chance of having the lowest noise floor possible:
- Before audio reaches the digital stage, reduce noise in the analog domain as much as possible. This means making sure that channel crosstalk is kept to a minimum, using high quality components throughout the buffering stages and the general I/O stages, using low-noise op-amps and JFET based preamps for high impedance input signals, rather than a generalized component that takes a line level signal and steps it down - which would be an example of how to do it badly.
- Making sure you use properly shielded signal paths and grounding techniques to avoid hum.
- Making sure your PCB layout design reduces opportunities for EMI as much as possible.
- Dual-gain input: take two inputs at different levels of gain, and dynamically blend between them. This is the same principle used in digital cameras to help reduce noise in images.
- Perform high-order noise shaping and dithering in Sigma-Delta ADC stages.
Those are just some of areas to look at. Whether NeuralDSP did this or just bought some components off the shelf and slapped them together, I simply cannot say.
But what I can say, and can show in images and audio (if you want it) is this:
View attachment 39964
View attachment 39965
The baseline noisefloor of the Quad Cortex when running in 4-cable-method (and also when just running into the front) with a real amplifier puts it firmly in last place when compared to Helix and Axe FX III. For a certain class of user, this is incredibly important, because making sure that each component in an entire system has the lowest noise floor possible, is one of the overall goals of putting together complex multi-device rigs. This is why things like the Bradshaw rig, the GigRig, and loopswitchers in general, exist in the first place.
So, I've never said the Quad Cortex was "useless" - that is a strawman. What I've said is, the kind of noisefloor I've seen from it when put at the centre of a complex rig, is unacceptable. Especially at this price point.
That is my opinion. I don't care if anyone else doesn't care about noise. Like I said, that is your prerogative. But what I do care about is objective measurement and valid comparison between devices.
For the avoidance of doubt; yes. I think the Quad Cortex is unacceptable
in this context. I think the Helix Floor and Axe FX III (and VP4 now) are acceptable. I am not expecting zero noise. I am just expecting minimal noise.
And to finish up, the obsession with shitting on people who are critical of the quad cortex is what is hilarious. The defensiveness is hilarious. The fuckwittery and sheer amount of technological and scientific ignorance is hilarious. The anti-intellectualism is hilarious.
And by 'hilarious' I really mean 'pathetic, stupid, and sad'.
Welcome back.
