![I have a Vox AC30VR I got for $100. Not a bad amp. Not as much headroom as I'd like though. Any thoughts on what this white adjuster on the board is I have a Vox AC30VR I got for $100. Not a bad amp. Not as much headroom as I'd like though. Any thoughts on what this white adjuster on the board is](https://i.redd.it/tm6jc9o2lf771.jpg)
I have a Vox AC30VR I got for $100. Not a bad amp. Not as much headroom as I'd like though. Any thoughts on what this white adjuster on the board is
![Amazon.co.jp: VOX AC30VR Guitar Amplifier Combo Type 30W Valve Reactor Circuit Included : Musical Instruments Amazon.co.jp: VOX AC30VR Guitar Amplifier Combo Type 30W Valve Reactor Circuit Included : Musical Instruments](https://m.media-amazon.com/images/I/71ol0nuIyqL._AC_SX425_.jpg)
Amazon.co.jp: VOX AC30VR Guitar Amplifier Combo Type 30W Valve Reactor Circuit Included : Musical Instruments
![I have a Vox AC30VR I got for $100. Not a bad amp. Not as much headroom as I'd like though. Any thoughts on what this white adjuster on the board is I have a Vox AC30VR I got for $100. Not a bad amp. Not as much headroom as I'd like though. Any thoughts on what this white adjuster on the board is](https://preview.redd.it/y0pwwe63lf771.jpg?width=640&crop=smart&auto=webp&s=dcac55616c5500dd3db16fa7a387231bf28aafe9)