NUX NBP-5 Bass preamp & D.I.

Reviw: NUX Melvin Lee Davis NBP-5 - digital bass preamp and D.I. with a lot of functions for a favourable price

Basic info

• Type: NUX Melvin Lee Davis NBP-5 Bass Preamp & D.I.

• Producer: Cherub Technology Co., Ltd., China

Brief overall evaluation

Pros

• Good sound

• Quality of workmanship

• Small dimensions

• Big number of useable features

• IR-based simulation

• Volume, HPF and LPF adjustment for IR impulses

• Simulation on/off switches independent for each output

• Noise gate

• Favourable price

Cons

• A separate distorted channel volume control is missing

• Distorted sound does not inspire everyone

• Some functions are accessible only

• Some useful features are only available when connected to a computer

• Input/output for the effects loop is missing

• Some users complain of problems with connecting to the computer (but I did not have such problems)

• Some discrepancies between the actual characteristics of the device and the characteristics declared by the manufacturer

Practical use

Design, ergonomics

The box is really sturdy and I also like the rough surface finish. The blue knobs may be able to put a little more resistance to reduce the risk of unintentional rotation, but they work well. I appreciate that this box is also equipped with silent footswitches. Toggle switches work precisely. From the mechanical point of view, I do not see any problems. I only consider the location of the power socket to be a small ergonomic problem in combination with my single-level pedalboard. Due to the location of the signal inputs and outputs, the preamp directly asks about the location in the upper left corner of the pedalboard. However, the power socket is just in the upper left corner of the box and, for example, the use of a bent power cable coming from the right side is problematic here if you want to use all inputs and outputs without any problems. But users of other types of pedalboards will have no problem.

Clean channel and equalizer

With equalizer knobs set to zero, nothing happens when the preamp is turned on, which is the expected situation. But this is relative. Preamp cannot work without some amplifier simulation (see the chapter on simulations below). The basic factory-set simulation is the NUX amplifier Melvin Lee Davis. It is very neutral and in this setting the sound really does not change after turning on the preamp. However, if you use the control software to set the simulation of the Aguilar amplifier (there are only these two in the default menu on the day of this review), then even with neutral corrections, the color of the sound will slightly change after turning on the preamp. When the MLD amplifier is set, the equalizer corrections are also unexpectedly fine, and even the maximum addition of bass will only slightly color the sound in the bass, sometimes you may not even notice the difference between neutral and maximum treble. Mids work quite well and the possibility of tuning them in the range of 160 to 1000 Hz is very practical. Such a small efficiency of corrections surprised me. But everything changes if you change the amplifier model to Aguilar in the software. This not only affects the color of the basic sound, as I have already mentioned, but the characteristics of the equalizer corrections will also change fundamentally. Suddenly, it is necessary to work with corrections very carefully. At least for me, simulation of an Aguilar amplifier is a clear choice.

Distorted channel

The distorted channel can be switched on or off by a separate footswitch. Distorted sound can be adjusted by two knobs - Drive and Blend. Drive sets a level of distortion. The distortion is not aggressive and even in the maximum setting it is not a brutal rumble. To my ears, the distortion sounds useful, especially for some saturation of the sound. When the preamp is off, the clean bass signal is distorted, while when the preamp is on, the distorted channel is in series after the clean channel, so the color of the distorted sound is significantly affected by the equalizer and amplifier simulation on the clean channel. The Blend control adjusts the ratio between the distorted and clean signal. And it works the same as I describe above, so when the preamp is off, the distorted sound mixes with the clean bass sound, and when the preamp is turned on, the distorted sound mixes with the clean channel sound affected by the amplifier simulation and equalizer.

What bothers me is the absence of a separate volume control for the distorted channel. Because the volume of the distorted sound increases as the distortion level increases, it is not possible to achieve a balanced volume when switching between a clean and a distorted channel. Blend controls and overall volume alone are not enough. For anyone who wants to turn distortion on and off while playing, it will be a nuisance.

Simulation

Preamp offers two independent simulations - amplifier simulation and IR simulation.

The amplifier simulation is a part of the clean channel signal chain and is therefore only applied to the sound when the clean channel/preamp is switched on. This simulation can only be controlled by software after connecting the preamp to the computer. At the time of writing, only two simulations were available - the NUX MLD amplifier and the Aguilar. The manufacturer promises to add more models in the future. Preamp does not allow operation without amplifier simulation. However, the MLD simulation is very neutral and does not affect the fundamental sound. The Aguilar simulation slightly affects the basic sound and also brings a significant change of the character of the equalizer corrections.

IR simulation is most often used to simulate the response of a real speaker or musical instrument. It is based on standard IR (Impulse Response) impulses (wav, 24bit, 48 kHz, length 1024 (20.33ms)). Impulses are managed by the software after connection of the preamp to the computer. IR simulation can be turned on or off using the dedicated toggle switches on the top of the box, separately for D.I. output (XLR) and for line output (TS). This is really very practical. The simulation is completely independent and is still active, even if there is no preamp, resp. clean or distorted channel on.

There is room for eight pulses in the software, four of which are fixed factory presets (speaker simulations) and four are empty for user impulses. Impulses can be imported very easily. I tried it, for example, with impulses simulating bass speakers from Shift Line and impulses simulating acoustic double bass from 3 Sigma. Graph of the frequency response of each pulse in the control software environment is also useful. In addition, it is possible to set the volume, low-cut filter (HPF, 20 - 300 Hz) and high-cut filter (LPF, 10000 - 20000 Hz) for each impulse. User impulses with their settings can be exported as a new impulse. Even factory presets for speaker simulations are quite useful, although in my opinion they lack high frequencies.

Inputs and outputs

Preamp offers two standard inputs - instrument with an input impedance of 1 MOhm and 6.3 mm jack and AUX with 3.5 mm stereo jack. Another input is the USB socket - see the information below. There are also several outputs available - parallel output (Through, TS) with unaffected original sound, line output (TS, imp. 1 kOhm) providing sound processed by the preamp and symmetrical D.I. output (XLR) from which processed or unprocessed audio is output depending on the setting of the Pre/Post switch. There is, of course, a Ground/Lift switch available.

Inputs/outputs for FX loop are not available.

USB and software

The last socket in the box is the microUSB socket. USB is used to connect the preamp to a computer, which opens up interesting possibilities. First of all, it is possible to update the firmware of the device and thus expand its capabilities in the future. From a practical point of view, however, the most important thing is that the entire preamp can be controlled in this way using specialized software, including functions that are not directly available. Even after connecting to the computer, the preamp must be connected to an external source, the power supply via USB does not work here.

The control software allows the selection of amplifier simulation, IR simulation settings, including pulse management, displays the current settings of all hardware drivers on the box and also displays the level of clean and processed signal. Using the software, you can turn on or off the clean and distorted channel or adjust the equalizer and volume. The controls of another preamp function, the noise gate, also appear in the software environment. For noise gate it is possible to set threshold and decay. The noise gate works well. It still works (if switched on), regardless of the state of the preamp.

USB audio routing is also a very practical software feature. It allows you to set the signal path for various uses:

• Normal ... complete processed signal to USB output

• Dry Out ... clean signal without processing and simulation to USB output

• Reamp ... playback of an previously recorded signal and its processing by the pedal

Thanks to USB, the preamp can also be used as an audio interface, eg for recording to a computer.

It is interesting that the control software does not have to be installed (in MS Windows), the .exe file is downloaded from the manufacturer's website, which is then directly executable. You can also download the ASIO driver to the preamp.

Individual settings and footage:

00:00 ... basic sound

00:08 ... amp simulation (Preamp ON, amp sim Aguilar, EQ flat, no cab sim)

00:16 ... cab simulation (Preamp ON, amp sim Aguilar, EQ flat, cab sim Trace Elliot 4x10" (TRC 410))

00:24 ... mid and treble boost, clean channel (Preamp ON, amp sim Aguilar, EQ mid/treble boost, cab sim TRC 410)

00:32 ... basic sound, 100% distortion (Preamp OFF, Drive 100%, Blend 100%, no cab sim)

00:40 ... basic sound, 100% distortion, cab sim (Preamp OFF, Drive 100%, Blend 100%, cab sim TRC 410)

00:48 ... clean channel on, 100% distortion, mid/treble boost (Preamp ON, amp sim Aguilar, EQ mid/treble boost, Drive 100%, Blend 100%, cab sim TRC 410)

00:56 ... 75% distortion, combination of clean and distorted sound 40/60 (Preamp ON, amp sim Aguilar, EQ mid/treble boost, Drive 75%, Blend 60%, cab sim TRC 410)

01:04 ... basic sound, 75% distortion, combination of clean and distorted sound 40/60 (Preamp OFF, Drive 75%, Blend 60%, no cab sim)

01:12 ... end

Overall evaluation

I think this device really offers a lot of good features for little money. It is small, it does not take up much space in the pedalboard. All features and sound options are really usable, the preamp is silent on the background. It offers a number of options for completing the sound exactly according to the ideas of the musician and/or sound engineer. Certainly not everyone will enjoy the distorted sound, and the inconvenience for those who need to work actively with it is the absence of a separate volume control of the distorted channel. If you're lucky enough not to run into problems connecting your preamp to the computer, and if you accept that some useful features are only available through the software, then this might be a good preamp for you.

I originally acquired this preamp only as a cheap first step to get acquainted with the digital way of processing bass sound with a vision to purchase some higher-level final solution based on this experience, but, maybe I won't take any more steps. But this decision will take some time to mature.

Technical and functional specification

• Technology: digital

  • Converter … sampling 48 kHz, A/D 32bit, frequency range 20 Hz - 20 kHz, dynamic range 100 dB, noise level -93 dBu

  • Latency … 1 ms

• Inputs

  • Instrument in (TS 6,3 mm), impedance 1MOhm

  • AUX in (TRS 3,5 mm)

• Outputs

  • Through out (TS 6,3 mm)

  • Line out (TS 6,3 mm), impedance 1 kOhm

  • D.I. out (XLR)

  • Phones (TRS 3,5 mm)

• microUSB socket

• Hardware controls

  • Clean channel: bass (+/- 12dB @40 Hz), parametric mids (+/- 17dB @160 Hz až 1000 Hz), treble (+/- 12dB @8000 Hz)

  • Distorted channel … gain, blend

  • Overall volume

• Hardware switches

  • Preamp (clean channel) on/off

  • Drive channel on/off

  • D.I. Pre/Post

  • D.I. Ground/Lift

  • IR simulation on/off separately for D.I. and Line out

• Dimensions… 105 x 115 x 58 mm

• Weight … 460 g

• Voltage … 9 V DC

• Current draw … <150 mA, in reality cca 300 mA

Software functions

• Amp simulation

• IR simulation

  • support standard IR impulses, wav, 24bit, 48 kHz, length 1024 (20.33ms)

  • 8 memory places - 4 presets (Aguilar DB 8x10", Ampeg SV 8x10", MarkBass 4x10", Trace Elliot 4x10") a 4 user's

  • Graph of the frequency response of the impulse

  • Sim volume, low-cut filter (HPF, 20 - 300 Hz), high-cut filter (LPF, 10000 - 20000 Hz)

  • Export of a new impulse

• USB audio routing

  • Normal ... processed signal to USB output

  • Dry Out ... dry signal to USB output

  • Reamp ... previously recorded signal to USB in, processed signal to USB out

  • Input and output volume

• Clean channel EQ controls

• Drive channel controls

• Noise gate ... on/off, decay, threshold

• Monitoring of dry and wet signal levels

March, 2021