SMPro Tube Box, Operating Manual

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and below the drum simultaneously. By reversing the phase on one of your micro-
phone signals you will achieve a better result, recording full range of signal without
a phase cancellation occurring. It is also used for matching the rest of your gear or
recordings or removing feedback when recording stereo pairs.
3.5.2 80Hz low-cut (high-pass) filter switch
The low-cut (high-pass) filter switch enables and disables the 80Hz high-pass filter.
Engaging this filter effectively removes low frequency “rumble” and other unwanted
noise by attenuating the signal dB below 80Hz.
4. making sounD
Make your physical connections
Simply make your signal connections by either connecting an instrument (guitar,
bass,mic etc) to the instrument input on the front panel, or connecting an input to the
rear of a 500 series power supply box.
Do you need phantom power or to change the phase of your input signal?
If you are using a condenser microphone that requires phantom power, select the
phantom power switch to the on position. You can also choose to switch the polarity
of your signal at this stage if required.
Set your input gain control
Set your input level. Adjust the input rotary control to an acceptable level. This is
a good time to check the clip indicator to ensure you are not overdriving the tube
pre-amp with too much signal. If your signal is too strong, reduce the amount with
the rotary control. If you cannot reduce the signal enough to stop the clip indicator
constantly illuminating, you can enable the -20dB PAD to assist in reducing the in-
coming signal gain.
Do you desire compression?
You can now choose to add some optical compression to your signal if desired.
You can select the compressor on/off switch to the on position. Set your attack and
release pots to the desired settings, and adjust the compression ratio rotary control
until you are satisfied with the result.
Set your output level
Adjust your master output level rotary control to the required amount.
5. Let’s play
The Tube Box’s opamps are in DIP8 sockets, this simply means that users can
easily interchange between different types of opamps to achieve different results.
We use a combination of 5532 and 4580 in the Tube Box so feel free to change then
around and we would be happy if you report the results to us as well.
5.1 Line Input Level
Right next to the Tube, you will find a Blue colored trimpot. This trimpot if for the
adjustment of the input level from the 500 series connector. To make the unit as
compatible as possible we left this as a variable resistor so that users can match the
level to their own system.