What is a UPS Backup and do I Need One ?

An Article by Daniel Pfister

I decided to share this based on the fact this has been a recent subject of interest…

I have done a lot of research on the type of UPS Battery Backup that was the safest to use with our Lowrey Organs – This all started back when I purchased my Rhapsody SU400 – The I.T. Department where I work suggested a UPS Battery Backup over a standard surge suppressor, as they provided cleaner, more stable power –

I started with a Cyber Power with “Simulated” sine wave output –

The First thing that I will point out is that all of this research was done on either my Rhapsody SU400 or my current Stardust SU530 –

As any owner of an SU series organ can tell you, they all have a very slight Amplifier Hum, some very quiet, some more noticeable –

Because both of my organs were located in my slate floored entrance hall, it was more noticeable at my home then at the dealer, which was a HUGE open carpeted space…

With that being said, the hum on the Rhapsody was definitely more noticeable then on the Stardust when on Line (House) Power… It was also confirmed by my dealer that my particular Stardust does have the ground loop isolator kit installed, which was added after production to reduce the amplifier hum…

During the testing of the UPS Battery backups on the Rhapsody I noticed that when you killed the Line power to the organ while it was powered up, the Amplifier Hum when running on the UPS Battery was SUBSTANTIALLY louder on the battery backup then on line power – This told me that something in the organ power supply or amplifier did note like the Simulated Sine Wave Output of the UPS Backup –

I tried Various Simulated Sine Wave Battery Backups from CyberPower, Tripp lite, APC/Snyder electric, Eaton, and Xtreme Power conversions – All of them caused an increase in the level of the hum when on battery power – Some far worse then others, but they all caused a very loud increase in the amplifier noise –

When I first started this, I did not really understand the difference between a Simulated Sine Wave UPS, and a Pure Sine Wave UPS – I did a lot of research on this subject- It then got more complicated because recently APC introduced a new series of UPS called the PRO series – They advertise these as having “Sine Wave Battery output compatible with modern computers using active PFC Power supplies” – after having a few lengthy conversations with the technical department at APC, I learned that these new APC UPS PRO’s are also still Simulated Sine Waves, with a slightly less square step then a normal simulated Sine wave – This was confirmed by the fact that these not only caused an increase in the Hum of the amp on the Stardust when switched over to the battery backup when the organ was powered on, but this

APC PRO series actually caused a very slight hum when the organ was actually turned off, but on the battery backup as would occur during a power outage –

Now the reason that this is concerning is that we do not want to cause any damage the organ – The point of the UPS is to provide cleaner, Stable power to the organ –

I was told that years ago Lowrey themselves’ recommended a UPS be used on any of the SU series to avoid glitches from voltage fluctuations –

New for the good news – If you purchase a UPS Battery Backup that is a PURE SINE WAVE output, I found absolutely no issues – No change in the hum when powered on with the battery backup, no hum when powered off and on battery backup – So clearly the organs are sensitive to the difference between a Simulated sine wave, and a Pure Sine Wave –

After months of reading many technical articles, there is clearly no one answer as to if the Square Simulated sine wave harms electronics – Many engineers say they will, many say they wont – The price difference today for the same capacity CyberPower PURE sine wave, and simulated sine wave is less then $20-40 dollars – For me it was not worth taking a chance – Pure Sine Wave is the way to go –

One last thing to note is that I am not sure where Lowrey came up with the wattage draw on these organs, but the wattage draw on the serial number sticker on my SU530 was very high compared to reality – My Stardust shows 430W on the production sticker (mine is an early production model SU530) – According to the load meters on all five of the UPS Battery Backups I recently tested showed an actual draw of 210-220 Watts when on battery power and playing at full volume – When tested with a digital load meter, I am getting 216W so it was close to all of the UPS Load Meters –

I hope that you found this information helpful…

Dan P.