Can you run a guitar amp from a UPS/Battery Backup power supply?

guitarman3001

Senior Member
Messages
12,187
I have some strange power issues at my house where some pedals are noisy and now in particular, my new Friedman Runt's FX loop is noisy and one pedal in particular hums like crazy. I'm sure it's not the amp as the same thing happens with other amps, but to a much lesser extent than with the Friedman, but either way, I'm almost sure it's caused by some interference, maybe my stuff is too close to my wifi router or my cable modem or my computer or something like that. I also have everything plugged in to some piggybacked power strips.

I'm trying to think of how to solve this because with the Friedman, the hiss and hum is extremely annoying in my very quiet house.

Is it OK to plug in my amp and pedals into an APC or Cyberpower UPS or will that give me even more noise and problems? I don't have one to try so I'd have to buy one or not buy it, based on others' experiences.
 

tiktok

Silver Supporting Member
Messages
25,059
I have done it, but only for backup purposes at a regular gig with weedy electricity, so if the breaker popped, all my gear kept going. I can't recall how long the battery was good for.
 

Hulakatt

Has done terrible things for a klondike bar
Gold Supporting Member
Messages
15,176
Why not go with something like a power conditioner?

Here's your winner! The UPC will only be good for a few minutes "off the grid" at a pop and, unless it is also a power conditioner, you will still have the saem problems while it is plugged in.

You want cleaner power to juice everything.
 

Fulldrive-1

Member
Messages
5,926
I just watched some youtube video of the J.H. Experience in '67-68.


Jimi played three 100 watt Marshalls driving six 4x12.
Noel Redding played three 200 watt tube Sunn heads running six 2x15.


How big of a backup battery would it have taken to keep the Experience going?
 

forum_crawler

Member
Messages
7,603
A power conditioner is what you need.
A UPS is not meant to "run" your equipment, instead, it is means to give you enough time to shut down all your equipment.

Some may include protection against power surges, but as a general rule, the application is completely wrong for guitar amplifiers.

On a side note, if you are going to spend the $200~$300 that you need to spend on a UPS designed to power a computer and maybe a printer, why not spring a wee bit more on a decent power conditioner for guitar?
 

logdrum

Member
Messages
2,123
I just watched some youtube video of the J.H. Experience in '67-68.


Jimi played three 100 watt Marshalls driving six 4x12.
Noel Redding played three 200 watt tube Sunn heads running six 2x15.


How big of a backup battery would it have taken to keep the Experience going?

Assuming 375 watts per 100 watt amplifier played loud, so a power draw of 3.4 KW
Assuming a 0.8pf, total apparent power = 3.4/0.8 = 4.25 KVA

So you need a UPS with 5 KVA capacity (I am rounding it up for extra margin)

For a 4 hour gig assuming 80℅ UPS efficiency, 5kVA/0.8X4 = 25kWh battery will be required. Or 25 12v car batteries rated at 100 watt hours, You need really good transformers for the inverters in this UPS . Many server data centers have systems that can do this but I do not know the battery cells they use. I had as a DYI beefed up my UPS by using a car battery.

I am not an EE by the way but work with a couple and they agree to this somewhat except that they do not think that each 100 watt amplifier is constantly drawing 3.4 amps and they just did a cursory check of my math. I could be wrong and hopefully real EEs in this forum can check.

My Mesa HB and Mark IV pull about 300-320 watts using a WattsUp meter when cranked, The 375 watts is from a search on google.
 
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