Voltage Regulator ????

Ronald Sikes · From: Corsicana, Tx

Does anyone use a voltage regulator, to plug your amp or digital processor's into, so you can maintain proper line voltage coming into your equipment? If so , what product would you recommend?
Thank's, Ron

Ray Minich · From: Bradford, Pa. Frozen Tundra

Sola is one brand, Topaz is another brand, Acme Electric also makes some, and they are CVS or Constant Voltage Stabilized transformers. They ain't cheap, 'cause they're a special transformer designed to run in saturation. A 250 VA or 500 VA unit should do the job. 100 VA is a little small.

Then ticking tap switchers they make for PC's might do the job but they're a little small too.

[This message was edited by Ray Minich on 13 September 2005 at 11:51 AM.]

John Daugherty · From: Rolla, Missouri, USA

Ron,keep in mind that most electronic equipment uses an internal DC regulator on its power supply. A lot of preamps use 24 volts and regulate it down to 12-16 volts to operate the circuit. As you can see, AC power drop will normally not affect these circuits. However, the Power amp portion of a guitar amp is usually NOT regulated, and can be affected by an AC line voltage drop.

------------------
www.phelpscountychoppers.com/steelguitar

George Redmon · From: Muskegon & Detroit Michigan.

i hear Furman makes a good unit

Ken Fox · From: Nashville GA USA

Get a good UPS (uninterruptable power supply) from a local electronics house or most amyone selling a computer system. Size depends on the wattage of the equipment you want to power up. Typically 1500 watt or so takes care of most musical stuff ( that is over 10 amps of power at 120 VAC).

Ron Randall · From: Dallas, Texas, USA

I think I am still on topic.
Have look at Furman's Power Factor Pro.
Extreme over voltage protection, transient voltage protection, series mode protection.
It is an AC filter that corrects the power factor. One can plug in several amps with no hum. I have been happy with mine. I run 2 tube amps, lexicon, etc with no hum.

Check their website. I am no electonics wiz. I gotta go practice.

Ken Fox · From: Nashville GA USA

The biggest problem with digital amps and processors is a low voltage. A UPS will prevent this and other problems. Below is some info from the web:

An Uninterruptible Power Supply is a device that sits between a power supply (e.g. a wall outlet) and a device (e.g. a computer) to prevent undesired features of the power source (outages, sags, surges, bad harmonics, etc.) from the supply from adversely affecting the performance of the device.
There are basically three different types of devices, all of which are occasionally passed off as UPSes.

Standby power supply (SPS). In this type of supply, power is usually derived directly from the power line, until power fails. After power failure, a battery powered inverter turns on to continue supplying power. Batteries are charged, as necessary, when line power is available. This type of supply is sometimes called an "offline" UPS.
The quality and effectiveness of this class of devices varies considerably; however, they are generally quite a bit cheaper than "true" UPSes. The time required for the inverter to come on line, typically called the switchover time, varies by unit. While some computers may be able to tolerate long switchover times, your mileage may vary. [ Some articles in the trade press have claimed that their testing shows that modern PCs can withstand transfer times of 100ms or more. Most UPS units claim a transfer time to battery of about 4ms. Note that even if a computer can stay up for 100ms, it doesn't mean that 100ms switchover is okay. Damage can still be done to a computer or data on it even if it stays up. ]

Other features to look for in this class of supplies is line filtering and/or other line conditioners. Since appliances connected to the supply are basically connected directly from the power line, SPSes provide relatively poor protection from line noise, frequency variations, line spikes, and brownouts.

[Some SPSes claim to have surge/spike suppression circuitry as well as transformers to "boost" voltage without switching to the battery if a modest voltage drop occurs. Often, as a "standby" UPS becomes more featureful it is called a "line interactive" UPS.

Hybrid [ or ferroresonant ] UPS systems. I only know one vendor who sells them - Best Power, Inc. [ Now called Eaton Powerware. Note that Powerware also sells line interactive and online UPSes. ] The theory behind these devices is fairly simple. When normal operating line power is present, the supply conditions power using a ferroresonant transformer. This transformer maintains a constant output voltage even with a varying input voltage and provides good protection against line noise. The transformer also maintains output on its secondary briefly when a total outage occurs. Best claims that their inverter then goes on line so quickly that it is operating without any interruption in power. Other UPS vendors maintain that the transition is less than seamless, but then again it's not in their best interest to promote Best's products.
[ Note: According to some sources, ferroresonant transformers in an UPS system can interact with ferroresonant transformers in your equipment's power supply and produce unexpected results. On the other hand, ferroresonant UPS systems don't kick off a lot of heat, which is important in some environments. The Moral: Test equipment to make sure it meets your needs before you buy. -npc ]

What I call "true" UPS systems, those supplies that continuously operate from an inverter. Obviously, there is no switchover time, and these supplies generally provide the best isolation from power line problems. The disadvantages to these devices are increased cost, increased power consumption, and increased heat generation. Despite the fact that the inverter in a "true" UPS is always on, the reliability of such units does not seem to be affected. In fact, we have seen more failures in cheaper SPS units. [ Note, though, that given the same quality inverter, you'd expect the one that runs least to last longest. These devices are often called "online" UPSes. ]

A UPS has internal batteries to guarantee that continuous power is provided to the equipment even if the power source stops providing power. Of course the UPS can only provide power for a while, typically a few minutes, but that is often enough to ride out power company glitches or short outages. Even if the outage is longer than the battery lifetime of the UPS, this provides the opportunity to execute an orderly shutdown of the equipment.

Advantages:

Computer jobs don't stop because the power fails.
Users not inconvenienced by computer shutting down.
Equipment does not incur the stress of another (hard) power cycle.
Data isn't lost because a machine shut down without doing a "sync" or equivalent to flush cached or real time data.

A UPS traditionally can perform the following functions:

Absorb relatively small power surges.
Smooth out noisy power sources.
Continue to provide power to equipment during line sags.
Provide power for some time after a blackout has occurred.

How long can equipment on a UPS keep running after the power goes?

A: That depends on how big a UPS do you have and what kind of equipment it protects. For most typical computer workstations, one might have a UPS that was rated to keep the machine alive through a 15 minute power loss. If it is important for a machine to survive hours without power, one should probably look at a more robust power backup solution that includes a generator and other components. Even if a UPS powers a very small load, it must still operate its DC (battery) to AC converter (the inverter), which costs power. A rough extrapolation from APC's documentation, leads me to guess that its 2000 VA UPS can operate its own inverter (with no extra load) for just over 8 hours. A 1250 VA UPS could run its converter for about 5. These are very rough guesses based on information provided by one vendor for one vendor

[This message was edited by Ken Fox on 14 September 2005 at 05:58 AM.]

[This message was edited by Ken Fox on 14 September 2005 at 06:00 AM.]

Michael Garnett · From: Seattle, WA

I'm in the market as well. The live sound engineering teacher at school told me just about anything by Furman is my best bet, AS LONG AS IT'S RATED FOR 15 AMPS. Other than that, get what you want. If you don't want lights on the front, you can get a RackRider or its equivalent for around $50 shipped. The Evil-bay is full of them.

-MG

Ken Fox · From: Nashville GA USA

That is fine if all you want is over-voltage protection! To protect from low voltage you need a UPS. It has a battery backup and inverter to supply AC power during brown out (low voltage) situations.

A UPS supplies all the of a surge protector and LOW VOLTAGE CORRECTION. You are not going to get that out of a $50.00 surge protector.

As an enginner and electrician I have dealt with this and other power conditioning problems for many years. You have to carefully analyze what is being sold against your needs. Your device must also be able to handle the wattage of the
device(s) to be powered (wattage equals voltage and amperage). In the case of say a Peavey Nashville 1000 amp:

Amp has a power consumption of 360 watt at 120VAC (3 amps). A 500 watt minimum UPS would be desirable.

[This message was edited by Ken Fox on 14 September 2005 at 07:19 AM.]

[This message was edited by Ken Fox on 14 September 2005 at 07:20 AM.]

Dave Mudgett · From: Central Pennsylvania and Gallatin, Tennessee

I use a Furman AR-1215 Voltage Regulator
http://www.furmansound.com/products/pro/reg/reg1.php

This is a 15-amp true voltage regulator, not a simple 'power conditioner'. That means it actually regulates back to 120V +_ 5V any AC voltage between 97 and 141 V.

I use a UPS on my workstation computer, because many OSs don't behave well when shut down abruptly. But if I'm on a gig or recording, I assume that if the power goes out, we're going to stop. Nothing wrong with a UPS at all - but they have batteries which need to be replaced, and I believe are quite a bit more bulky and expensive, watt-for-watt, than a voltage regulator. The AR-1215 is a single-rack unit.

I've been using my AR-1215 for about 6 years without event. Many clubs I play have low voltage issues. I have even played gigs powered by a very long extension cord connected to a 15/20-amp service for the whole band - for example, on a barge on the Susquehanna River - where everybody else's amps sounded terrible, but mine sounded OK. It's not a panacea, but it does deal with a lot of practical voltage problems, in my experience.

I agree with Ken that the typical inexpensive 'power conditioner' is only useful for things like voltage spikes. I view them not too much different than a simple power strip with surge/spike protection. A real voltage regulator is going to set you back a lot more than $50.

Andy Schick · From: Kingston, Ontario, Canada

I use a Furman Ar-1215
So far so good. I have used for about 2 years.
Andy

Ronald Sikes · From: Corsicana, Tx

Thank's for all the info. guy's. It appears that a lot of people are interested. The website on americanmusical.com show's a Furman AR1215 for $389.9 (rackmount voltage reg). They also show a rackmount power conditioner for around $129.00. I don't know if the conditioner would be O.K. or not.
Ron

Ken Fox · From: Nashville GA USA

I have talked to deveral people with problems with the digital power supplies inthe DPC-750, DPC-1000 and Session 2000. If a club exhibits a constant low voltage situation the Furman AR12-1215 is ideal! It found one for $315.00 on the net, just keep searching they are out there at a good price.

I have a frined with a Session 2000 and his problem was caused by a sudden dump in club power, typically caused by too many things on the circuit. A good surge in band volume can drop the voltage suddenly. That's where the digital equippment needs the help like Furman offers. If the voltage drops lower than 97 volts, the Furman will not help you much. That is getting into the "brown out" area of voltage loss. Still for most circumstances looks like the Furman would work well.

Keep in mind a 500 VA UPS should not cost much more than $150.00! They are not all that heavey and there are rack mount versions available as well. So look at all the options.

Great discussion and thanks for the info on the Furman products!

Dave Mudgett · From: Central Pennsylvania and Gallatin, Tennessee

According to Furman, the AR-1215 continues to regulate between 75-150 VAC input - outside those limits, it shuts down - but doesn't maintain 120 +- 5V. Agreed, though, this is not a panacea. Nonetheless, I have found this helps my sound a lot, and when I don't bring it, I often regret it. Frequently with bad electrical service, I find that every time the bass player hits a loud note, I can hear my note envelope change because he is loading down the circuit. The Furman has helped that a lot, for me.

My biggest issue with using a UPS in this situation is that the batteries typically only last a couple of years, in my experience. For gigs, I want something that helps, is completely transparent, and requires no maintenance.

Michael Garnett · From: Seattle, WA

Hehe, Dave... I'm buying one for my bass rack, so I guess that's not going to be a problem, is it!?!?

Plus, I'm playing max 350w through a 210 cab, so it's not ever going to get that bad because of me.

-MG

Dave Mudgett · From: Central Pennsylvania and Gallatin, Tennessee

The issue is total current draw by the amp, not the audio output 'watts rating'. Also, the relation between average AC power and AC current/voltage is a bit more complex than the usual DC power = voltage x current. Instead,

AC_power = AC_voltage x AC_current x cos(angle between AC_voltage and AC_current).

That last term is called the "power factor", PF, and can be smaller than one for a reactive load (containing either capacitance or inductance), so a load can draw more current than it might appear even from the AC_power drawn, which includes inefficiency in the amp.

I usually get an idea of the max current draw by looking at the amp's power fuse value. This is generally a conservative upper bound, but I'd rather be conservative.

For example, my Dual Showman Reverb has a 2.5 amp fuse, Deluxe Reverb 1 amp, LTD 400 6 amps, and Session 500 8 amps. I just add up the fuse ratings, and make sure that's less than 13-14 amps (I don't ever push the Furman to the absolute limit - it is not as efficient if the voltage is low).

I have a hard time imagining that one 350 watt amp is going to ever draw anything like 13-14 amps. But a full-tilt LTD 400 and Session 500 together is pushing the envelope, IMO. I've used the pair of them together for outdoor gigs, but I wouldn't let anybody else plug in.

Ron Randall · From: Dallas, Texas, USA

FWIW
The following is from Furman:
"Furman Sound introduces the all new Power Factor Pro, redefining power conditioning for the guitarist, bassist, or keyboard player.

Today’s AC power is contaminated. Whether you play in a stadium, bar, or rehearsal space, they all have one thing in common, the AC power is supplied from your local utility. What’s worse is that the “power factor” supplied from your building’s AC outlet is typically poor, thanks to increasingly overtaxed power lines and raised line impedance.

In fact, the quality of AC power has been so poor for so long, most musicians have no idea how great their amplifiers could really sound. When the AC power factor is poor, amplifiers sound muddy because their power supplies can’t deliver when pushed. The scream and cry from a guitar loses bite and harmonics, basses lose their punch and weight, keyboards sound nasal, losing clarity, attack, and extension. Not so with Furman’s Power Factor Pro..."
http://www.furmansound.com/products/pro/pwr_cond_seq/cond/pfpro.php

I am curious to know: will a UPS solve this problem?

Ron

Ken Fox · From: Nashville GA USA

http://www.apcc.com/resource/include/techspec_index.cfm?base_sku=BP700UC

This one appears to have voltage regulation. Keep in mind the max power rating. Typically the max wattage is located by the AC power cord. A Nashville 100 has a power consumption of 360 watts, so I would think this would handle it just fine.

Pricewise they are in the $120.00 range.

Michael Garnett · From: Seattle, WA

Dave, that's a good point. I never liked electronics or EE stuf much, I was always more hands-on. And everybody knows when you put your hands on electricity it hurts. I was just saying, it's not that much wattage, therefore it's probably never going to draw that many amps. The fuse on the back of my SWR SM-400 is 7 amp slow blow, and interestingly enough, there's an 8 amp fuse on each side of the amp's outputs. That's the only thing in the rack other than the DT1000 tuner, so I really probably don't need a Furman, but it'd be nice to have, and some cheap insurance for power surges and drops.

-MG

Dave Mudgett · From: Central Pennsylvania and Gallatin, Tennessee

Michael - yup, 7 amps fuse rating sounds about right. My rough 'rule of thumb' on a solid state amp is that the max current draw is often on the order of double that indicated by the RMS wattage - 350 Watts x 2 is on the order of 700 watts, on the order of 7 amps when the power factor is considered. That should not tax the AR-1215 at all, or the Furman Power Factor Pro Ron mentioned above. The PF Pro looks like a slightly downgraded AR-1215, rated for 12 amps instead of 15. There may be other differences, but it's not enough cheaper to motivate me to choose it over the AR-1215, which has been their workhorse for a long time.

On the 8 amps on the audio outputs, remember that the voltage is lower. Power = Voltage x Current x Power Factor. So 350 nominal watts / 8-amps / 2-sides (left and right) indicates a nominal voltage on the order of 20 Volts.

Hey, I was an E.E. prof for quite a while, and a theoretician at that - I just can't help myself.

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