Are voltage regulators a good investment?

Discussion in 'Amps and Cabs [BG]' started by TCollins, Sep 11, 2000.

  1. TCollins


    Apr 4, 2000
    I just got a new Mesa 400+ w/a new Mesa/B 2x15 cab. & I want to protect my investment as much as possible. I remember reading in one of these threads (Psycho Bass Guy-I think) mentioned that the "line/power conditioners" such as those offered by Furman--don't really have anything to do with line voltage--that, if you want that kind of protection-be prepared to shell out more cash. I see that Furman offers a
    Line Voltage Regulator for under $400. My question is this: Is fluctuation of line voltage "deadly" for tube amps (or any amp for that matter)? Are there any other precautions that a bassist with a powerful amp can take? Do lights/other amps & P.A.'s drain power in ways that can be damaging to Mesa Boogie circuitry? I already own a Furman RackRider power conditioner--is this enough protection?
    Thanks for listening!
  2. I wouldn't worry about any of the stuff you mentioned. You've got a piece of modern equipment, so it most likely has varistors built in for deadly-spike suppression on the 120V line. Just unplug it from the wall whenever it is not in use or power is surging or flickering due to electrical storms to avoid lightning run-ins.

    The other equipment you mention does not pose a threat, but if you try to run 10,000 watts worth of PA and your amp on the same 18 Gauge 100' extension cord, you'll have some trouble. Some light dimmers may put some noise on the line, but nothing that would harm your amp.

    You could buy a low-cost multimeter and learn how to check outlets before you plug into them. But I don't even do that.

    Those power conditioners seem like overkill to me, but so do $3000 basses. :D

  3. Ive played at rodeos amd ball games with low line voltage and never hurt my amp but, it sure is misrable playing a low volume distorting amp
  4. MtnGoat


    May 7, 2000
    I used to use a Furman Ar117 line regulator and it worked beautifully for about 4 years (only one year with the bass rig). The unit originally cost me about $500 and was supposed to deliver a constant 117 VAC as long as the input voltage was between 87 and 140 VAC. I tested the unit with a variable voltage supply and it did exactly what it was supposed to do. The only problem was when I started using it with the bass rig it failed twice within six months. When I say "failed," I mean that several of the transistors on the daughter board exploded, presumably from too much heat. Although the unit is rated for 15 amps, I blew this thing up twice just running my bass amp through it, which was only drawing between 2-4 amps. A great unit, but as Furman told me, it is not really meant for high current loads. I would recommend it if you are going to use it for studio equipment or other low-current-draw type of applicaitons.
  5. An old-timer EE professor told me once about a lab instructor that wanted to use a SOLA constant voltage transformer to supply the VTVM's (vacuum tube voltmeters) for better accuracy. The first time they tried to use it, 5 of the 6 meters were going nuts, the needles wouldn't stay still, couldn't get accurate readings, etc. They couldn't understand why one of the meters was working perfectly and 5 hated the constant voltage transformer.

    This is what they figured out. The SOLA constant voltage transformer puts out a clamped sine wave, it looks a lot like a square wave. Most electronic equipment operates off the Peak of the sine waves it is fed. Since the SOLA was supplying a nasty wave shape, even though it had a constant average voltage value, the electronic devices hated it. Why did the one meter work fine? They opened it up, and it had been built wrong. Instead of having a PI shaped power supply filter section like the other 5 meters, the first cap had been accidentally soldered onto the other side of the choke. So instead of having a PI filter, it just had a choke input filter. The choke input filter does not care about peak voltage as much as a capacitor input filter, it just cares about average value. So it worked fine. Pretty cool.

    I have no idea what methododology the Furman regulator uses. Sounds like it actually rectifies the AC, then electronically produces AC again. So it may or may not produce a nasty waveform. Probably doesn't, since it is supposed to be better than raw line.

    PBG is right, to actually do some good, the equipment is going to be huge. Not worth it to me.