my 755 seems to run hot, any ideas? I have enough air running through it. deftech power towers are connected.

Well, these amps all generate a good bit of heat (particularly the 770, 755, 7100, and 750 -- the 200's are slightly different) by their nature. If you have a couple inches of clearance above the 755 and an open front on the rack (open back wouldn't hurt either), you should have plenty of ventilation going on. It will still be warm to the touch, however. How hot is your amp getting? Are we talking about in the 90F-100F range, or are you seeing it hotter than that?

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

Gonk, thanks for the reply. I got the 755/950 combo in july and it always did run warm, even at high levels. I wouldn't say 90 degrees but lately I would say hot to where it goes into protect mode. At least I THINK ITS PROTECT MODE! here is what happens, after about 2 hrs of playing music the left front speaker would click out. I would then feel the amp and it would be hot in the upper left hand side. At this point I would turn it down to about -70db and after about 10 minutes it would come back on. once it got hot again the front left speaker would go out again. just for your info I have deftech bp 2006s in front along with aprocenter 200 in the center. I also have a couple of other devices hooked up but I don't think they would be the problem. EVERYTHING is hooked up to a MONSTER POWER STRIP.(hts 1100}. Oh, the lights in my room tend to flicker or drain when ever I turn up the volume with music.If the amp is doing this why doesn't the power strip take care of the problem? Or do I need a another power strip in addition to the one I have. thanx.

If the lights are dimming when the amp draws heavy current, that means there is probably a little too much (or more than a little too much, in which case you should really have the wiring checked) resistance in the wiring somewhere in the wire’s path prior to both the amp and the lights. The power strip works to help the power remain ‘safe’ for those items that are plugged in to it, but it still lets power through if there is a ‘power hungry’ device plugged in to it. When that surge of current is drawn through resistance in the house wiring, the voltage drops where the resistance exists. In fact, if the voltage is sagging, the amp may draw even more current in an attempt to keep its internal voltages up to where they should be. Many amps actually run hotter if the supply voltage is too low because they are drawing more amps to satisfy the number of watts needed, even if your common sense tells you, “less volts = less watts = cooler.”

I would first check out what the actual voltage is at the wall supply when the amp is playing loud, not after any power regulation that would be ‘hiding’ the variations by trying to compensate for them. Because the voltage may be fluctuating with heavy bass rhythms, a digital voltmeter may not display the voltages fast enough to show you what’s happening, so try an analog meter also. If the voltage is dropping by more than a volt or two, there may be a problem. If the voltage is dropping by five or ten or more volts, brother, you’ve got problems, especially if the voltage is starting out barely within the specified supply range for the amp. If there is a fair amount of resistance in the wiring somewhere, then the amp may not be the only thing heating up. If there is a poor connection at one of the outlets in a series of outlets before your amp, for instance, the point at which the voltage is dropping is also dissipating watts, and that means heat! Depending on the load, sometimes enough heat to melt insulation and risk a fire. How do I know? Both education and I’ve seen it happen.

If your supply voltage is no problem, or has been corrected, then I would next suspect the amp. In my situation, I have used one end of the amp for main left and the other end of the amp for main right, with the center in the middle. That way the most ‘power hungry’ channels are separated in the case and they’re not helping each other keep warm. I’ve checked with Outlaw support, and they said that any amp channel may be used for any playback channel. The outlaw amp channel labeling is for convenience. If after trying these things, you still have the problem, perhaps your amp is still in the warranty period and can be checked out.

I hope it works out for you!

thanx, for the advice the voltage scenario is scary, I am going to look into it. As far as the amp being the problem I have already sent it in to be checked out. I hope that's the problem because the voltage thing is something that is foreign to me. I have checked out all other appliances and outlets in the house, nothing seems to be running hot. this house is only 3 yrs old I've only lived here about 10 months. An electricion checked out the house and said it was in excellent condition.without the amp in my rack and without anything turned on, there is a voltage input meter on my power strip that says voltage input is 110. Shouldn't it be 120? I have 0 knowledge about such matters who should I call to check out my wiring?

I don’t think that the 110v reading, in and of itself, is a worry. A practicing electrician among our ranks may be able to offer an official opinion, but in my understanding different areas and electric companies have varying standards as to the voltage delivered, ranging from 110v to 120v.

Caution: don’t risk yourself, others, or property if you are not confident you can do the following safely.

You might still be able to do an approximate check of the voltage drop, if any, at the outlet that serves you HT equipment. With the 755 gone and the other gear turned off, monitor the voltage at the outlet while turning on a hair dryer plugged in where the 755 had been. Do not use a heat setting that will draw more current than your power strip is rated for. Hopefully you have some information on the dryer, or other chosen high wattage device, as to how much power will be used at different settings.

Note any voltage change both at the moment you turn on the hair dryer and if there is any voltage ‘recovery,’ such that the voltage, if it dropped at the moment the dryer was turned on, came partially back up while the dryer continues to operate. If the voltage barely drops when the dryer is turned on, the voltage supply and/or wiring was likely never the problem. If the test shows the voltage at the outlet remains very near the original 110v, also repeat the test but while measuring the voltage available at the outlets of the power strip. If the level drops more at the power strip than at the wall outlet, then the power strip may be a contributing factor.

I hope I’ve been more of a help than a supplier of worry!


[This message has been edited by bestbang4thebuck (edited November 29, 2003).]

hey, thanx again, I plugged in a hair dryer and turned it on full blast, the part that tells you current usage read 4A which I think means amps. right? Then the voltage output read 110 volts but didn't really move from there even after I let it run for about a minute. Also I didn't notice the flutter in the light. I next put the dryer straight into the wall and I didn't really notice anthing out of the ordinary. Later on I did notice the light flutter when I turned on the vacuum cleaner in the same area.Anyway I'll find out monday from Scott what the deal with the 755 is. Oh, since I have your attention let me run the following by you. I have deftech bp2006s and an acoustic research sub using the lfe. The 2006's have built in subs. I have the fronts set to small crossed over at 40/sub on. My center is set to small crossed over at 60. I don't have any surrounds but they will be deftechs more than likely set to small crossed over at 60. Does this sound right? Since I'm using the seperate lfe what should I have it crossed over at? Or does it matter? I'm trying to figure out what would sonically be the best solution for my setup. I would like to keep my bass confined to all three woofers up front. my mains are hooked up using the regular wire method(binding posts) thanx for all the help.

Hey, here's another issue that hopefully you have a answer for. I can't believe I totally forgot about this, after the initial problem with the 755 I tried to calibrate again and I could not get my mains past the 71 to 72db point. Before the problem I was able to get the 3 front channels at or about 85db.(all settings were flat or on 0 including the volume.)I hate the fact that this is happening with my first set of seperates but I really need to make sure that I didn't do anything dumb to cause this.THANX GUYS.

Gonk,Bestbangforthebuck, I don't know if you caught my message to D-rowe but to make a long story short it looks like my hot amp problem might be the crossover in my deftechs. Chad from deftech pretty much explained it to me. I will know for sure next week when they look at my amp at outlaw. I didn,t know a speaker's crossover would make amps shut down like that.(see my thread with D-rowe for more details.) thanx.