Power Considerations

This information pertains to AC power sources for your L1®.

Electrical Power

As a general note, we want to remind you that all electrical equipment must deal with poor power conditions and power outages. Hardware and software designs can be sophisticated in this regard and we put enormous effort in this area.

At a certain point, if the voltage drops too low from the wall circuit, or there is a power outage, contemporary digital electronics including ours will start a reset sequence. Assuming the AC power recovers, the reset sequence with digital electronics usually takes a few seconds. If that few seconds is longer than the power outage, it can be a frustrating wait.

There are practical things that musicians can do that will minimize the chance of an interruption in their performances – practices that are valuable to know and use in general for all stage equipment.

• Use AC extension cords that are as short as possible. Do not use a 100’ cord when a 25’ cord will do.
• Do not use thin-gauge or flimsy extension cords. Good cords are worth the extra expense.
• Avoid the practice of stringing AC extension cords together: if you have 20’ to the wall socket, use one 25’ cord rather than 3 x 8’ cords. The reason is that the electrical connectors at the junction between cords can introduce extra resistance, especially if they are bent or corroded.
• Split power-hungry equipment (amplifiers and lights) over as many different power circuits as you can. Lots of power-hungry equipment loaded onto one circuit will lower the voltage and can cause equipment resets and failures, especially in very loud musical performances.
• Check for non-performance-related equipment on stage circuits that may contain compressors or large motors: refrigerators, air conditioners, snow cone machines, etc. can cause a large drop in the voltage. If possible, move these appliances to other circuits or have them turned off during the performance.

Source: Bill-at-Bose

Surge Protectors

From Hilmar-at-Bose

Surge protectors are not a bad thing, although the PS1 (as well as the L1 Model I, Model II, and all our other products) have built in surge protection.

"Surge" means a lot of voltage coming through the power over a short period of time. That's pretty rare and the main cause is lightning, some accidents involving power lines (mostly on poles) being cut and touching something they shouldn't (e.g. the wrong side of a power transformer) and some really big compressors (e.g. industrial-sides freezers or fridges) turning on or off.

With the exception of lightning and some very bad power accidents, the PS1 can handle that all fine by itself. With lightning, anything is possible. No piece of equipment that I know will survive a direct hit into a directly connected power line. But then again lightning might strike a few blocks (and transformers) away in which case a surge protector might be able to take the first hit and die quickly enough to protect the attached equipment.

In this regard even cheap surge protectors will work fairly well and there is only a really small number of cases where a cheap and very expensive surge protector might make a difference.

On a side note, its a good idea to have all equipment that connects to the PS1 on the same power strip. That helps with ground loops. On the other hand it's not a good idea to turn things on and off with the switch on the power strip. That may cause your fuse to blow (due to the so-called "in-rush current") and might result in pops and clicks.

The proper way to turn things on is to follow the signal, i.e.

1. instruments
2. outboard effects processors
3. PS1
4. external power amps

Turning off be done in reverse.

Source: Hilmar-at-Bose

Power Strips

There is no technical reason why a power strip, a power cord or any sort of power conditioner should make a difference. Our system (and many others too) are designed to deal with all sorts of AC power fluctuation and have high quality internal regulators. These regulate with much higher precision that any external device could do anyway, so "conditioning" or "cleaning" up the AC power doesn't make any audible difference whatsoever.

Source: Hilmar-at-Bose

Power Conditioning

We do not recommend external voltage regulators because we found that in many cases they cause more harm then help. The amps and power supplies in the L1 use highly efficient switching technology, Many voltage regulators are not a good fit for this technology since they are simply not fast enough.

The L1 is designed to be quite resistant against any AC voltage swings and will operate fine even down at 97 Volts.

Source: Hilmar-at-Bose

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We Bose designers do not believe that a power conditioner provides more headroom, dynamics, better sound, or more fidelity for our equipment.

There are a number of technical reasons for this that I won't go into online, but a good way to think of it is that we have already put in all the power conditioning required to make the products sound as good as possible.

Source: Bill-at-Bose ST 09:09, 12 August 2008 (EDT)