Shift Bias to tweak the harmonic balance¶

The Bias knob moves the operating point on the tube transfer curve, changing the balance of even and odd harmonics the saturator produces. Use it to fine-tune the character of the saturation after you have set Drive.

Before you start¶

The Tube stage must be enabled on the side you want to adjust (TX or RX). See Bypass the tube from either chain.
Drive should already be set high enough that the transfer curve is visibly bent. See Dial Drive until the curve starts to bend (TX warmth or RX tone shaping).
Open the floating editor by double-clicking the TUBE stage in the CHAIN widget on the TX or RX side. The editor is titled "Aetherial Tube — TX" or "Aetherial Tube — RX".

Steps¶

Locate the Bias knob in the centre row of the editor, to the right of the A / B / C model selector.
Turn Bias from its default of 0 % toward higher values (up to 100 %) to shift the operating point and increase asymmetric saturation.
Watch the transfer curve: the curve shifts its bend point as you turn the knob. The live input ball tracks the new operating region in real time.
Stop when the harmonic balance sounds correct for your use case.
If the overall level changes noticeably, adjust the Output knob to compensate. See Compensate level changes with Output.

What each control does¶

Control	Default	Valid range	Persisted setting key
Bias (TX)	0 %	0 % to 100 % (internal 0.0 to 1.0)	`ClientTubeTxBias`
Bias (RX)	0 %	0 % to 100 % (internal 0.0 to 1.0)	`ClientTubeRxBias`

The Bias knob uses a linear mapping. The displayed value is a percentage. Internally the setting is stored as a value from 0.0 to 1.0 in ClientTubeTxBias (TX side) or ClientTubeRxBias (RX side).

Tips¶

Bias interacts with the selected tube character. Try each of A, B, and C to hear how the same Bias value produces different harmonic results with different models.
The Bias knob is also present in the docked applet tile (the compact five-knob row beneath the transfer curve), so you can make quick adjustments without opening the full editor.
Changes made in the docked tile and the floating editor stay in sync; a 30 Hz timer keeps both views updated.

Bypass dim¶

When the Tube stage is bypassed, the entire docked applet tile renders at reduced opacity (approximately 55 % of full brightness). This matches the dim effect used on the EQ curve and gives a clear at-a-glance indication that the stage is inactive. The tile returns to full opacity as soon as the stage is re-enabled.

Troubleshooting¶

Bias knob has no audible effect — Drive may be at or near 0.00 dB. Bias only shifts the operating point meaningfully when the curve is already bent. Increase Drive first.
Level changes when Bias is adjusted — This is expected. The asymmetry introduced by Bias can raise or lower the apparent output. Trim the Output knob to compensate.
Docked tile appears dimmed — The Tube stage is bypassed. Re-enable it on the TX or RX side. See Bypass the tube from either chain.