How to address unwanted distortions (english)

Some users may experience clipping and noise artefacts after updating. While some distortions are inherent to the simulation (and also to be found on a real Hammond organ, like AO28 triode distortions and power amp overdrive), sometimes old parameter settings or a too aggressive tapering may lead to unwanted distortions. Here is a short manual to locate and defeat these, valid for HX3.5 as well as HX3.6 boards.

Locate Distortion/Noise Source

Locating the distortion source is crucial. There are several places where clipping may occur in the simulation, as internal audio processing is limited to 16 bit due to FPGA constraints:

• Busbar accumulators
• Matching transformer
• AO28 preamp
• Tube power amp
• Speaker crossover
• Speaker simulation

Finding the distortion source is handled from top to bottom. Set *Rotary* and *Tube Amp* (*Tabs* #1136/#1137) to *Bypass* and *Volume Pots* *AO28 Tube Age* #1089 to 0, so they wont affect your sound. Play a handful of notes known to be critical. Repeat your tests always with the same notes played. If reducing a parameter mentioned does not reduce clipping, leave it where it was. Do not change parameters randomly, as this will limit the dynamic range and eventually tube amp overdrive.

Distortions still occur when Rotary and Tube Amp set to Bypass

This means that clipping occurs in the organ itself (first three points).

• Reduce parameters #1082 to #1085.