- Volume/Blend Stack
- Treble/Bass Stack
- Mid/Mid Stack
- Blend-Pickup Switch
- Passive Tone
- Active/Passive Switch
- Gold Finish
The U Retro's high quality circuit uses three stacked knobs and includes an active blend circuit plus a 3 band equaliser with bass, variable frequency mid, treble and bright function. A passive tone circuit is also included which operates in both active and passive modes.
A very gentle built in contour gives immediate colour without detracting from the basic sound of any bass. The active blend circuit prevents the loss associated with many passive basses where, when both pickups are up full, the signal from one pickup feeds into the other and vice versa.
However, a switch is included to allow a passive equal mix of both pickups. A second switch - basic "get-you-out-of-trouble" passive mode is included in case the battery dies in crucial circumstances, but this mode allows lots of useful settings too.
A standard 9v battery is used to power the U Retro.
- Blend & Pickup Switch
- Treble: (+12dB @ 3 kHz, -12dB @ 1kHz)
- Bright: (+8dB @ 7kHz)
- Bass: (+15dB @ 50Hz)
- Mid Boost/Cut: (+/- 12dB)
- Mid Freq (150Hz - 3kHz)
- Passive Tone
- Active Passive Switch
The upper knob is the Volume which has two sections under the same knob. A high impedance for the passive path and a low impedance section is used for the active circuitry. When used active, this knob has active circuitry after it'so that the feed to your amplifier is a low impedance drive.
The lower outer knob is the Blend balance for the pickups. Turn it fully clockwise for the neck pickup alone and fully anti-clockwise for the bridge pickup. The midway position, which has an indent, gives an equal mix of both pickups. The balance between the pickups is continuously variable with progressive level compensation towards the single pickup settings. Important:- The Pickups switch (by the blend) must be set pointing towards the jack for the Blend to function.
The upper knob is the Treble control with boost and cut. The central 'flat' position is indented. The cut settings work on lower frequencies compared to boost to give a deeper sound when the top is rolled off.
Pull the Treble knob for the Bright setting.
The lower outer knob is the boost only Bass control. The frequency band of boost gets progressively lower as the boost is increased. An indent midway is included to aid the setting of this control.
The upper knob controls the amount of Mid boost or cut at frequencies according to the setting of the Frequency knob. The midway indent is the 'flat' position.
The lower outer knob is continuously variable and sets the Mid frequencies for boost or cut.
The passive tone pot consists of two sections, one for each pickup. Two sections are necessary since the pickup signals are kept separate and fed to their own individual input amplifiers prior to the electronic blend circuitry.
To retain the characteristics of a true passive tone, its circuitry is connected directly to the pickups at all times and therefore function in both active and passive modes. The roll-off frequency is set to give a deep mellow sound.
Towards the jack for active, the opposite for passive.