DirtyPumper

The effect sounds alright, maybe could be a bit more subtle. I wish there was a high pass filter on the input, to have the possibility to preserve the low end.

I don't like that even when the dirt and the drive knobs are turned all the way down, the plugin still heavily distorts. In my opninion, plugins should be completely transparant when all the knobs are turned down. Using the mix knob in FL Studio instead does not work due to phase issues.

I like the feature to decrease either the positive or negative amplitudes, although I feel like this could be combined into a single knob, as turning both knobs down is the same as decreasing the out gain.

Lastly, the UI is too large for how little knobs the plugin has. It is also not rescalable in FL Studio, and the UI consists of low resolution images.

Dirty Pumper is pretty fun to play with. It works good on Hammond giving it soft overdrive sound without adding too much highs. I don't think it will be good on guitar, but on organs it does the good work. On DX7 it is good as well. On drums, I assume will do the job well, but haven't tested it there. Its not actually pumper, since there is no LFO tremolo.

Plugin has two knobs for IN, OUT gain - this is good and quite unusual in world of free plugins.

GUI is too big and lowpass filter is not doing much, I would make it bit stronger.

Worth downloading.