It can be pretty interesting trying to get things to work well in this country. I’ve been working with a new group and we needed to come up with Microphones and a amplifier for the meetings. While this shouldn’t be too difficult to come by it’s the little things like providing clean power that can be a real issue.

Hurricane power HP 450c PA amplifier

After working with an old stereo amp with a mic input (which barely worked) someone donated a Hurricane power HP 450c PA amplifier, sounds impressive huh? Well, the little guy actually works pretty good as long as it gets good power. Something that doesn’t happen very often out in the compos.

At times we get city power during our meetings, but more likely we are running off our generator. City power or “la Luz” is pretty hit or miss here, there is no way of predicting when we might have power or for how long. When we do get power the voltage can vary more than 40-50 volts. Unfortunatly the Hurricane 450c can only take about a 5 volt change before it starts to make popping sounds, cutting out, etc. This is pretty easy to take care of with a small 1000va voltage regulator. I’m using a Sky STDR-1000VA which does a good job as long as the voltage stays between 90 and 130, which usually is the case, but not always.

Running a generator when ever there is no street power can get a little expencive with gasoline at over $5.50 USD per gallon so we are working on buying an inversor (invertor). Funny thing about the whole house inversors you buy in the DR, they are not of the best quality and put out a dirty power (instead of a clean wave sign, it is a square wave), many electronic don’t like this form of power including an expensive HP Printer I brought from the states. While my printer won’t even turn on with the inversor the hurricane amp turns on but with a very loud 60hz hum, which pretty much drowns out anything you are trying to amplify.

The solution

If you made it to this page you are likely looking for some sort of solution to this same problem. While you would think that there should be an easy way to cope with this problem I’ve yet to find it. My solution has been to keep adding band-aids until I came up with a workable PA Sound system.

Solution Part 1 was to regulate the incoming 110 (ish) voltage to a steady 110. The SKY STDR 1000va power regulator that I bought from La Sirena managed that problem, with the help of an auto transformer that we use to drop the power companies current 170 += voltage down about 60 volts. The auto transformer (which is called a reducer here), is a new addition due to the fact that the power company decided it was easier to raise the voltage and require people to use a reducer to get it close. 170 appears to be their version of the 220 that is usually fed into houses in the US, but being that most of the houses here are wired to receive 110 instead of 220 a reducer is needed.

The second part of the solution was to try to clean up the inversor power so that the amp wouldn’t create the overpowering hum. This was a little harder to come by. I ended up going to a computer store and picking up a UPS. Now the idea of a UPS is to make it so that is you have a brown out, or you power drops off for a few second the UPS continues to provide power using a back up battery. While this is somewhat useful, for me the filtering capacity of the battery back up system was the highlight of the unit.

My UPS of choice (I only had two to choose from) was a Omega DV-650. While I was told that it works well with a inversor, in reality it is only tolerant of my inversor. If will at times beep for several minutes before accepting the inversors power. While that means tolerating the beep ( or opening up the unit and killing the pizo beeper), after a bit of a pause my amp will turn back on and function with only a slight buzz instead of the overpowering one that I get without the UPS.

So, got a better solution? Feel free to add it to the comments, I’d love to hear it!