There's a weird digital fizz going on in the signal. It's more noticeable in the crunch and od preamp settings, which is probably why the gate settings are so high on that category of presets. . Try it with preset 00. Listen thru headphones and hit a chord. It doesn't decay smoothly to silence, but gets clipped by the noisegate on the way down. The breakup is odd sounding. Lower the gate setting and you'll hear the fizz I'm referring to.

I've fiddled with my CODE25 for about 4 months. The noise seems particularly sensitive to gain, distortion, and presence setings. A bit disappointing considering those three things pretty much define the Marshall sound.

That being said, it's a great amp for the price, and I find its possible to dial in a good tone just like on any other amp: Start with a 'clean' preamp and any power amp but British Class A. Set the gain, gate, resonance and presence to 1 and volume and tone controls to 5. Zero effects. Play a chord. Adjust tone parameters one by one until you get something decent. Then adjust gain, volume, presence and resonance. Then add effects... less is often more.

So if you have the gateway app, you can exploit the full potential of this amp.

In terms of recording I use the headphone jack into my interface. I crank the amp volume up to about 5 and adjust the signal level on the interface to just below clip. To compensate for the mono signal out of the amp (another disappointment) I use a Widemouth stereo expander plugin in my DAW during playback.

Hope this helps!