DBX 231 Dual 31-Band Constant Q Graphic.Excellent Condition with just a small amount of rack rash on the top, not noticeable in a rack. Front panel has no marks.
The dbx 231s Dual Channel 31-Band Equaliser is a reliable, budget-friendly analogue graphic EQ offering 1/3-octave constant-Q bands, switchable boost/cut ranges, and balanced XLR/TRS connectivity. Users on platforms like Cruthers Customer Reviews generally agree that it delivers great sound for the price, though some note a slightly higher noise floor than expected. Key Specifications & Features

• Channels & Bands: Dual-channel, 31 bands per channel using 1/3-octave constant-Q filters.
• Boost/Cut Range: Switchable between ±6 dB or ±12 dB.
• Filters & Control: 50Hz low-cut filter (12 dB/octave) and ±12 dB input gain range.
• Connections: XLR and 1/4" TRS inputs and outputs.
• Performance: Frequency response of <10 Hz to >50 kHz with a dynamic range over 108 dB. 

For a detailed walkthrough of the physical controls and features on the unit: Pros and Cons

• Pros: Solid build quality, precise surgical feedback control, and flexible range switching (±6 dB mode is great for fine-tuning).
• Cons: Lacks rubber feet for non-rack setups out of the box, and the noise floor can be slightly noticeable in ultra-quiet studio environments.