DHA ValveTone VT1 Acoustic Preamp

The ValveTone 1 Acoustic uses a single 12AX7 (ECC83) valve to generate classic pure valve tones. The ValveTone 1 Acoustic is a low gain effect and is intended to be used to warm up the tone of an electro acoustic guitar but it will also work well with a microphone for vocals or recording.

The ValveTone 1 Acoustic is fitted with 2.1mm external PSU adaptor for use with a 12v @ 1200mA external supply. The user should use a well regulated external supply as the better the regulation then the less the hum when at higher gain levels. The inner of the connector is the positive, there is reverse polarity protection so no harm will be done if you get it wrong. There is an internal switch mode power supply which doubles the 12V to 24V for the valve anodes or ‘plates’.

The effect is always on when the power is connected and there is an LED to show you when the power is present.

There is a very clean op-amp boost circuit in the effect which helps get the required line levels of output when operating at very low levels of gain. There is a small black pre-set inside the effect which adjusts the boost level, you can adjust this to suit your set up. You are safe to adjust the pre-set when the effect is powered up as the voltages inside are very low.