Designed by the creator of Tonelux, the Studio Projects SPM5 is a unique high quality microphone/instrument preamp with an added ‘radiance’ feature, which provides adjustable high end 2nd harmonic content to your signal without boosting overall output. This is useful for adding clarity and presence to your signal source.

The input circuitry is discrete, while the output is transformer balanced. The preamp provides a clean, low-noise 60dB of gain. The front panel features a combo jack for plugging in directly and there is an impedance switch, which can be useful when employing certain microphones, such as ribbon, or dynamic type. Radiance The radiance control, located just above the multi-jack on the front panel, is used to add ‘sparkle’, or ‘clarity’ to the input source signal. This effect can be used sparingly,or heavily, depending on the how far clockwise the radiance control is adjusted. Polarity The “POL” switch reverses the polarity of the microphone signal. It can correct for the wiring of older, non-AES equipment, change the character of the sound from guitar mics and, when using two mics for “Mid and Side” stereo recording, invert the phase of one of them. High Pass Filter (‘HPF’) This helps remove stage rumble, handling noise and low frequency resonances. The cut frequencies are continuously variable from 25Hz to 200Hz. Adjust the control so that the unwanted sounds are removed but required sounds do not lose their bass content. Use the HPF ‘ON’ switch to make comparisons between filtered and unfiltered sound. Gain and Noise All preamplifiers inevitably generate some noise due to the electronics they require. As long as this is low compared with what you are trying to record, the signal will hide the noise. In fact the SPM5 electronics are extremely quiet, such that almost all the noise is due to the source impedance of the microphone. However, you might still hear some “hiss” during the gaps in the vocal or music. Bearing in mind the amount of gain in a typical monitoring system, it is generally a good idea not to use preamp gains greater than 40dB or 50dB. With careful microphone placement, it should rarely be necessary to do so. So try to place the microphone as close to the sound source as you can without overloading it, so as to get as much signal out of it as possible. Then set the ‘GAIN’ control to give only as much gain as is needed to get a decent level on the meter.