What is the MA-4HP?
The MA-4HP is a high quality, direct-coupled microphone amplifier that serves to increase the level of a microphone signal to a standard reference line level signal without contributing significant noise or distortion and provides the option of reducing low frequencies.
Why does the MA-4HP not have phantom power?
Being a direct-coupled, transformer-less design requires that phantom power not be provided internally without additional expense or compromise. We have a high quality 4 channel external phantom power supply available with a hard-wired, 4m Mogami snake for condenser (capacitor) and active ribbon microphones (ex. Royer R-122, etc.). The use of an external power supply for phantom reduces cost per channel and extends the usefulness of many other line level signal processors, effectively increasing the number of microphone amplifiers in a studio. For example, many dynamics processors (and some eq’s) have more than enough gain to amplify a microphone signal. Manufacturers of condenser microphones commonly offer such stand-alone units as well.
Why doesn’t the MA-4HP have phase reverse?
One less source of degradation in the signal path as well as requiring the user to reverse the polarity of the signal by more deliberate means ( i.e., using a reverse polarity cable on the input or outputs as necessary). In addition, as the MA-4HP was designed with 2 independent, isolated balanced outputs per channel, there is tremendous flexibility in configuring the signal path. For example, the user may want reverse the polarity of an additional microphone on a source - as in the common case of top and bottom snare/tom mics - and would implement a reverse polarity cable on the input to the mic amp when setting up the mic in question. Another scenario would be the potential to use one of the two outputs available on each channel to create an M/S matrix without the compromises involved in using additional equipment such as a mixer. This can easily be accomplished by using a cable to reverse the polarity of one of the outputs of the Side mic in an M/S microphone arrangement and then feeding this now stereo signal into two converter channels, stereo line inputs on a console or two inputs on a tape machine. In addition, either output may be unbalanced without level loss or affecting the other output.
Why does the MA-4HP have two line driver outputs per channel?
For the reasons stated above and additionally to feed separate destinations such as FOH vs. monitor desk, recorder and cue mix or separate recorders with the ability to pad one output without affecting the other.
Why isn’t there a bypass for the high pass filter?
This unique servo based, first-order filter doesn’t require bypassing as the frequencies below the cutoff are not in the signal path. This results in the least degradation and phase shift possible and doesn’t require a switch or relay or additional circuitry to implement. Note: The 3dB down point is 63Hz at 12:00 and 100Hz at 2:00 and the slope is a gentle 6dB per octave.
Why isn’t there any metering or clipping indicators on the MA-4HP?
Since there are several standards for full scale digital, metering is best left to the device being fed. Additionally, as the clip point of the MA-4HP exceeds +30dBm (with a minimum gain of 8.5dB this equates to greater than +21dBu input level handling) clipping is unlikely to occur and additional circuitry would increase the cost of the unit.
Why do all SMG products use an external power supply?
To reduce the possibility of inducing noise or hum in the signal path as well as reducing the overall cost to the user. One SMG PS-2856 can power 3 units (24 outputs) with all outputs simultaneously delivering +24dBm into 600 ohm loads. In less demanding circumstances more units may be powered. Since each channel within each unit has its own over specified regulators, there is no interaction between channels.
Why should I buy a MA-4HP?
There may not be one preamp that will be the perfect choice for every microphone on every source, but as things move more towards the DAW environment and the modeling plug in options that this format provides there is an increased necessity for clean mic amps that allow the ability to color the signal “in the box” as needed or not. The need for preamps that solve this problem and are affordable enough to own in significant quantity is very much the new reality - especially as A/D converters have increased in quality and become more accessible in larger channel counts. Even the musician recording one or two tracks at a time can now have the “luxury” of setting up several mics on a source and switching between them as desired. One last note – I developed these mic pres as a product that serves my own needs and desires and that I myself would buy with my hard earned money as well as being built to not ever allow regret in making that purchasing decision. These mic amps (and all of our products) are proudly manufactured in the United States of America using top quality components and stand up to scrutiny along side any microphone amplifier ever built. Thank you for your time and your consideration of our audio products.