BASTL Bestie 5 Channel Stereo Mixer User Manual
- June 10, 2024
- BASTL
Table of Contents
Bestie 5 Channel Stereo Mixer
User Manual
BEST
STEREO MIXER FRIEND
BASTL INSTRUMENTS
Bestie Manual
Bestie is a 5-channel stereo mixer with up to 20 dB boost, mute switch per
channel, and flexible connectivity. However, Bestie is not just a mixer but
also a stereo distortion/saturator with a pre-routed feedback channel that can
create juicy, crunchy sounds. Mixing with Bestie can be pure vanilla if you
keep all the levels left of the 12 o’clock position, but once you start
boosting, Bestie can quickly turn into a Beast. Once you start to overload the
mixer, the sounds can start to fight for dominance.
The dedicated headphone output offers a loudness control with a smooth mixdown
overdrive character and a pre/post mute switch for pre-listening to all your
channels before unmuting them to the speakers.
USB-C and AA battery power options make it perfect for portable setups without
compromising sound quality.
Channels 1 and 5 have a flexible connectivity scheme accommodating 2x mono
cable for left and right channels or 1x cable mono to split to both channels
or a classic stereo jack.
The Feedback Channel
Channel 3 serves as a feedback channel, which means it routes the output back
to the input. If you plug anything into the Channel 3 input, it functions as a
normal input channel.
When utilizing Channel 3 as a feedback channel, the level before the 12
o’clock position functions as an added distortion and gain. If boosted beyond
0 dB, it will begin to self-oscillate and generate increasingly deeper tones
as the channel is further amplified. At maximum settings, it produces distinct
tremolo-like effects. A big part of the sonic aesthetics of Bastl Instruments
and Casper Electronics is influenced by the so-called no-input-mixing
technique. This is the technique of routing the output back to the input on
mixing consoles and using gain and EQ to create different tones and noises
without plugging any signals into the mixer. However, fascinating outcomes
arise when these feedback signals are interrupted by elements such as drums.
They interact with the feedback tones and compete for dominance. Bestie is
well suited for such experiments and directly encourages you to overload its
circuitry and make the signals go ape.
Features
- 5 stereo channels
- Mute switch with light indication per channel
- Level control per channel with up to 20 dB boost
- Low noise preamps with sweet overdrive character (same as Dude)
- Inputs via 3.5 mm stereo jacks
- 3.5 mm jack output
- 3.5 mm jack headphone output with loudness control
- Pre/Post mute option for the headphone output (pre-listen)
- Channel 3 is normalized to the output, making it a default feedback channel.
- Channels 1 and 5 have two 3.5 mm jacks to also accept dual jack stereo or mono signals.
- USB-C power or 4x AA Battery power
Technical details
- Dimensions: 101 x 69 x 51 mm
- Current consumption: 90 mA (without headphones), up to 200 mA (with headphones)
- Spacing between jacks: 12 mm (center to center)
- Input impedance: 22 kΩ
- Output impedance: 100 Ω
- Headphone impedance: 8–250 Ω
A Power up
Connect USB-C to a powered USB connector or insert 4x AA batteries. If using
batteries, we highly encourage you to use rechargeable ones. Flip the power
switch to the ON position, and the light on the front panel under the name
Bestie will light up.
Note: USB-C input will take priority over AA batteries. Batteries will
not be charged when using it.
B Inputs
Inputs 2, 3 and 4 are 3.5 mm stereo jack inputs designed for stereo linelevel
devices.
Channels 1 and 5 have flexible routing options:
- Connect a mono jack to the R input. It will be normalized to the L input and you can hear the same mono signal in both left and right channels.
- Connect a mono left jack to the L input and a mono right jack to the R input to have a stereo signal via independent connectors.
- Connect a stereo jack to the L input and to get a stereo signal. It will work the same way as Channels 2, 3 and 4.
All inputs are AC coupled.
EXAMPLES OF CONNECTING DIFFERENT STEREO / MONO SOURCES
The Feedback Channel
Channel 3 serves as a feedback channel, which means it routes the output back
to the input. If you plug anything into the Channel 3 input, it functions as a
normal input channel.
When utilizing Channel 3 as a feedback channel, the level before the 12
o’clock position functions as an added distortion and gain. If boosted beyond
0 dB, it will begin to self-oscillate and generate increasingly deeper tones
as the channel is further amplified. At maximum settings, it produces distinct
tremolo-like effects.
A big part of the sonic aesthetics of Bastl Instruments and Casper
Electronics is influenced by the so-called no-input-mixing technique. This is
the technique of routing the output back to the input on mixing consoles and
using gain and EQ to create different tones and noises without plugging any
signals into the mixer. However, fascinating outcomes arise when these
feedback signals are interrupted by elements such as drums. They interact with
the feedback tones and compete for dominance. Bestie is well suited for such
experiments and directly encourages you to overload its circuitry and make the
signals go ape.
CHANNEL 3 BEHAVES AS IF THERE WAS A CABLE GOING FROM THE OUTPUT TO CHANNEL
3 INPUT. REMOVE THIS FEEDBACK LOOP BY PLUGGING ANY CABLE INTO THE CHANNEL 3
INPUT
C Mute
Press the Mute switches to change the mute state of a channel. When the light
is on, it means the channel is active, and the light off means it is disabled.
You can also slightly press the button to make it temporarily unmuted.
D Level/Boost
Use the Level knob to set the gain of each input channel. In the 12 o’clock
position, the gain is 0 dB (same level as the input); when turned fully
clockwise, the gain is +20 dB (10x gain). When the signal is boosted a lot, it
will saturate nicely in the NE5532 op-amp. For clean results, mix with the
level knobs below 12 o’clock. Boost all signals to make them interact with
each other.
E Mix Out
All channels get mixed in the MIX OUT – a line-level output. Use this output
to connect to your destination line input.
F Headphones
The dedicated headphone output is suitable for driving a wide range of
headphones, including high-impedance headphones. Use the Headphones knob to
set the level on the headphones. The headphones knob will also boost the
signal level, and can be used as mixdown overdrive.
G Pre/Post mute headphone switch
This switch selects whether the headphone output listens to the mixdown before
(PRE) or after (POST) the mute switches. This is useful for listening to all
signals on the headphone output while only some (unmuted) are sent to the main
output. This could be used to pre-listen to some channels before sending them
to the main MIX OUT.
NOTE: When using Channel 3 as a feedback channel (with nothing plugged
into the Channel 3 input), and with the headphone switch in the PRE position,
the muted Channel 3 level will boost the headphone output, as it mixes in the
MIX OUT signal. This can provide an additional overdrive character without
feedback. If Channel 3 is unmuted, it will produce normal feedback.
H
The trimmer, accessible with a small flat screwdriver at the right side of
Bestie, is there to gain-match the left and right channels. While mixing, a
mismatch usually has little effect because the amplitude tolerances are
minimal. But when feedbacking Bestie, it can manifest in audible tonal
mismatch and distortion differences. This effect can either be used to widen
the stereo field (mismatch the gain) or narrow it (tightest possible gain
match).
INSIDE HACKING – PLEASE NOTE THAT THE FOLLOWING ACTIONS VOIDS THE
WARRANTY!
1 &2 Jumpers JP1, JP2, JP3, and JP4
If you take Bestie apart (by removing the knobs, nuts, and screws) and look
under the large capacitors on both the left and right sides, you will find a
few solder jumpers for both Channel 1 and 5. These can be cut with a knife to
increase the channels’ gain up to +35dB (55x gain), which could be useful when
using pickup microphones or other lower signal devices. The input impedance
remains at 22k. These jumpers can be closed again by applying a blob of
solder.
3 Jumpers JP5 and JP6
Cut both of these jumpers with a knife to disable the feedback routing for
Channel 3.
4 Jumpers JP7 and JP8
Cut both of these jumpers with a knife to increase the maximum gain of the
headphone output from 1.5x gain to 3.6x gain. This can be useful for high-
impedance headphones or if you want to use the headphone output to distort the
mixdown.
USB noise, what is causing it and how to avoid it
Some USB devices, such as sound cards or mixers, may have separate USB ground
and audio ground. On the other hand, other devices, including Bestie, share
the ground between USB and audio. When connecting audio and USB ground, you
may create ground loops and introduce noise into your system, especially if
one or more of the devices is not suitable for this kind of connection (such
as the OP-Z, K-Mix, Motu M4, etc.). In this case, it’s recommended to power
Bestie and the problematic device from
separate USB power sources or use the battery power option.
SETUP EXAMPLES
Mixing drums with feedback:
If your drum machine has separate outputs, you may want to consider mixing
them externally and adding saturation to enhance their sound. The Bestie’s
internal feedback channel interacts perfectly with drums. Activate Channel 3
to get more dirt out of your drum machine.
Preview different parts on
headphones while muted in the MIX OUT:
When mixing multiple synth or drum parts, you can use the headphone output
with the switch in the PRE mute position to pre-listen to all the channels
before unmuting them to the speaker system.
Stereo saturation distortion/feedback after stereo effect:
Stereo saturation is an under-appreciated concept in the hardware domain, as
most distortions and saturators are not stereo. For animated distortion sound,
use the stereo auto-pan effect before Bestie. Chorus or any other stereo-
widening modulated effects will also add subtle yet very elegant
complexity.
Stereo feedback loop with an
effect:
To expand on the feedback channel idea, consider patching the headphones
output into a stereo effects box and patching it back to the input. This way,
the effect will play a major role in sculpting the feedback tone and behavior.
Experiment with options like chorus, auto-pan, delays or even pitch-shifters.
Anything in the time domain will work great, but even a simple EQ or filter
will go far. Experiment!
Use Bestie as a performative stereo aux
sub-mixer:
Most analog mixers lack stereo aux sends. If you would like to use a stereo
effect with a stereo source, you might want to use Bestie as a simple stereo
mixer to mix your effect. It will also be great for performing because you can
use the mute switches to toggle the effects on and off.
Custom in-ear mixdown for
live performance:
If you’re preparing for a live performance and require an in-ear monitoring
system, but your computer audio interface cannot provide an independent
headphone mixdown, you can use Bestie to achieve this. Simply split all
channels being sent to the front-of-house mixing engineer and mix them
independently using Bestie.
CREDITS
Development Team Václav Mach, Martin Klecl
Supervised by Václav Peloušek
Main Tester Juha Kivekäs
Beta Testers David Žáček, Milan Říha, John Dinger, Peter Edwards, Oliver
Torr, Patrik Veltruský, Niels Aras, David Herzig, Marco Menzle
Management John Dinger
Graphic design Anymade Studio
The idea turned into reality thanks to everyone at Bastl Instruments and
thanks to the immense support of our fans.
more info
and video tutorials
www.bastl-instruments.com