The challenges with upright bass, and how the preamp addresses them
Body resonances and unwanted feedback
The large resonant body of an upright bass produces strong acoustic resonances that can interact with amplified sound, leading to feedback. Depending on the room, frequencies can sometimes develop unwanted feedback when the instrument is amplified. The Stanley Clarke preamp has two different tools to handle these situations, both connected to the same control knob, labeled “Filter”.
There is a switch tied to the Filter control that lets you choose whether to use it as a High Pass filter – where you can filter out everything below a selected frequency -or as a Notch filter – where you make a deep, steep cut around a selected center frequency to handle uneven resonant tones, including problematic frequencies often associated with wolf tones.
When the low end creates feedback, use the HP setting and turn up the control until you eliminate the feedback, while keeping as much of the lows as possible.
If the feedback occurs when you play a specific note, use the Notch setting to find the center frequency where it occurs and cut it out of the mix.
If you don’t need the filter, simply turn the control all the way to the left to the “Off” position.
Acoustic character and EQ requirements
Another challenge is that an upright bass has a different tonal character than an electric bass. While the two instruments share much of the same frequency range, the upright bass naturally produces more acoustic body resonance and low-mid content, whereas an electric bass often delivers a tighter, more extended low end. Preamps for bass usually reflect the range of an electric bass and are not optimized for the acoustic bass performance.
The EQ filters on the Stanley Clarke preamp are tailored to support and handle the range of the upright bass, with a lower center frequency on the Bass filter to add a little more bottom to the naturally middy character of the upright bass when boosted. In the same way, the Treble filter is centered at a slightly higher frequency to bring out more presence and pluck attack when needed from the naturally duller upright strings.
Internal and external mics
Many professional upright bassists blend a pickup with an external microphone. The Stanley Clarke preamp is prepared to handle this, as one of the channels accepts an XLR input for connecting an external mic. The XLR input can also provide phantom power for condenser microphones when needed.
You can use one channel for your internal pickup and another for the external, then blend the signals to find the right balance. If a phase issue occur, simply use the Phase Inverter switch on channel A to fix it.
Dynamics and input levels
The Stanley Clarke Signature Acoustic Preamp offers studio-grade headroom, allowing it to handle the wide dynamic range of an upright bass without unwanted distortion or compression.
Many upright-bass pickups are piezo-based and perform best when connected to a very high-impedance input. The 10 MΩ input stage helps avoid the thin or brittle sound that can occur when these pickups are connected to standard bass preamps or mixers.
Both 1/4” inputs on the Stanley Clarke preamp are 10 MΩ impedance. This helps preserve the natural character of piezo and other upright-bass pickups, while the filter section provides additional tools for controlling feedback at higher stage volumes.
Suitable for electric bass too?
An ideal A/B box for electric bass
Many bass players switch between a five-string and a four-string bass at the gig. Or, between two basses with different character. While the Stanley Clarke preamp is designed for upright bass, it is an ideal solution for those times too.
The reason is that both channels have the exact same control setup, making it easy to adjust the tone where needed from a common starting point. Just plug in your basses on individual channels and use the A/B switch to activate the one you pick up.
Where to buy the Stanley Clarke Signature Acoustic Preamp?
The Stanley Clarke preamp is widely available at online stores and local EBS dealers. It’s been one of the best-selling EBS pedals since its arrival. Pick it up from your favorite online dealer, or find the nearest local dealer here.
