Describe the Gain node as square without its name (#384)

The Gain's plate lost its engraved name and is now 160x160.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Sounds.md

@@ -424,7 +424,7 @@ response of a Reverb, and as what the Sound FX tab tries out. Its row means noth
 
 | Node | What it does |
 | --- | --- |
-| **Gain** | Louder or quieter, in dB (`Gain (dB)`): 0 leaves it alone, -6 is about half as loud, +6 twice. Above 0 the sound can clip. In the graph the node is drawn as a small device (#384): the Compressor's brushed plate in orange, 160x220 graph units, with one chrome knob between its inputs and its output. The knob works as the Compressor's do: drag up or down, a double-click resets it to 0 dB, each turn one undo step, the wheel zooms the graph. 0 dB stands straight up, and the quiet end below -24 dB takes only a fifth of the turn. A linked `Gain (dB)` greys the knob. There is no tab and no meter. |
+| **Gain** | Louder or quieter, in dB (`Gain (dB)`): 0 leaves it alone, -6 is about half as loud, +6 twice. Above 0 the sound can clip. In the graph the node is drawn as a small device (#384): the Compressor's brushed plate in orange, 160x160 graph units without an engraved name, with one chrome knob between its inputs and its output. The knob works as the Compressor's do: drag up or down, a double-click resets it to 0 dB, each turn one undo step, the wheel zooms the graph. 0 dB stands straight up, and the quiet end below -24 dB takes only a fifth of the turn. A linked `Gain (dB)` greys the knob. There is no tab and no meter. |
 | **Pitch** | Higher or lower, in semitones (12 is an octave, 0.5 a quarter tone). The sound **keeps its length**, also when the pitch changes while it plays. The pitch is made where the sound is read, so an effect before the Pitch acts as if it came after it. On a [Chip](Instruments#chips) of an instrument it moves the frequency of the Chip itself. Its `wet` takes the semitones from 0 up to all of them, see [below](#bypass-and-wet). |
 | **5-Band-EQ** | Five bands in dB: 80 Hz and 12 kHz as shelves, 250 Hz, 1 kHz and 4 kHz as peaks. A band at 0 does nothing. |
 | **Parametric EQ** | Up to 10 bands, each a filter of its own type, frequency, gain, Q and slope, drawn together as one curve. The node shows its editor right in the graph, and a **double-click on the node's title** opens the same in a tab. Both show the spectrum of what passes the node. A new node has no band and does nothing. See [below](#parametric-eq). |