- sets the output level of the effect to your amplifier, there is a lot of gain generated by the valves and selectable op-amp generated boost and this will overdrive the input of your guitar amplifier with ease.
- Gain 1
- sets the level into the second stage of the valve on channel 1 and hence the level of gain. Use your volume control on your guitar to control the gain on the first stage of the valve, you will find that the ValveTone Dual MK2 responses very well to this and you can control the break-up distortion like this.
- Gain 2
- sets the level into the second stage of the valve on channel 2 and hence the level of gain on that channel. When channel 1+2 (high gain) is selected the overall gain depends on both Gain pots as Gain 1 and therefore channel 1 is always selected.
- Clip (3 position switch)
- is a neat trick you wonâ€™t have seen before on this type of effect. Clipping acts the selectable boost op-amp so the Boost switch needs to be on before there is any effect.
- In the center position (None) there is no clipping selected and the only clipping heard at higher gains is the valves soft chipping.
- The Si position connects two Silicon diodes to produce a harder Fuzz type clipping.
- The Ge position switches in 4 Germanium diodes, this is a much softer clipping, please note because the Germanium diodes reverse voltage is much lower than Silicon the volume will drop.
- Tone controls
- are the normal Treble, Mid and Bass as you would expect.
- T/B (switch)
- is Top Boost and this adds both gain and Treble to the tone.
- FAT (switch)
- adds mid to the tone giving a fatter tone. When T/B and/or FAT are used the normal tone controls have a reduced effect. The tone controls act on both channels.
- Tone By-Pass (switch)
- which means the user can completely by-pass the tone circuit, this adds gain.
- Boost (switch)
- adds extra clean volume to the pedal using a low noise high gain op-amp, this is useful when low levels of gain are selected for Jazz or Blues.
- Inside the box there is a small black pre-set pot on the stripboard with the op-amp on it, this adjusts the boost volume so play with this to suit your needs.
The ValveTone Dual Bass uses two 12AX7 (ECC83) valves to generate classic pure valve tones. There are two selectable channels with a separate Gain on each, channel 1 produces low to mid gains while the foot switch selected channel 2 adds two extra valve stages to produce high gain levels. There is a true By-Pass switch plus an LED indicator for both effect on and when 1+2 is selected. The ValveTone Dual Bass is capable of producing a very wide range of gains to suit all types of playing. It is intended to be used in front of a valve amplifier, but will also work well with solid state amps or even recording set ups acting as a valve pre-amp.
The ValveTone Dual Bass has a built-in voltage doubler circuit; this generates 24V from the existing 12V power supply. The 24V is used to supply the anodes or plates of the valves, this adds more clean headroom, gain and output volume to the pedal over the standard ValveTone Dual MK2 range. This model has a 24 or 12v plate voltage selector switch.
The ValveTone Dual Bass is fitted with 2.1mm external PSU adaptor for use with a 12v @ 500mA external supply but a supply of 1.2A or greater is recommended. The user should use a well regulated external supply as the better the regulation then the less the hum when at higher gain levels. If you find there is a lot of hum at high gains then the problem will be the supply is not well regulated. I have found that Switchmode supplies work well and these are standard for higher current types, so it is likely that any 12V supply over 1.25A will be a switchmode. The inner of the connector is the positive, there is reverse polarity protection so no harm will be done if you get it wrong.