Whole House Amplifier Recommendation?

[Matt Meiser]

I've got speakers in 3 rooms and on our deck that are powered by a whole house amp. Each set has its own impedance matched volume control. The amp I bought about 4 years ago went bad after a year (stopped working, burning smell) and was repaired by the manufacturer under warranty. Today, the same thing happened again. Its out of warranty so I'm checking into their repair cost but expect it to approach replacement cost. Can someone recommend an amp to me? Its fed by low-level signals from our main HT system. This one has an auto-on feature which I need the new one to have, where it powers itself on when it sees an input signal.

[John Coloccia]

I've got speakers in 3 rooms and on our deck that are powered by a whole house amp. Each set has its own impedance matched volume control. The amp I bought about 4 years ago went bad after a year (stopped working, burning smell) and was repaired by the manufacturer under warranty. Today, the same thing happened again. Its out of warranty so I'm checking into their repair cost but expect it to approach replacement cost. Can someone recommend an amp to me? Its fed by low-level signals from our main HT system. This one has an auto-on feature which I need the new one to have, where it powers itself on when it sees an input signal.

What's blowing up on the amp?

[Matt Meiser]

I'd guess its quality related. I pretty much use it every weekday. Pretty much the same, fairly low volume, pretty much the same speakers on every day. Just started distorting after being on a couple hours then a minute later--poof. IIRC, and its been about 3 years, that's pretty much the same thing as last time.

I'll probably pull it apart and see if I can see any burned components this time. Last time since it was under warranty I didn't touch it.

[Greg Peterson]

Whole house amp? You might try early 70's Marshall 100 stack. It will cover your house, your neighbors house and likely half the block.

[Jim O'Dell]

I'd check the impedance the amp is seeing from the speakers. Are these on 70 volt lines like commercial background music speakers, or are these regular 8 ohm home speakers? If the latter is the case, and they are not wired right, the amp may be seeing less 4 ohms at the amp, which for an amp set up for 8 ohm speakers is not much better than a direct short. You might have to wire one pair in series, and parallel them with the 3rd pair. If I remember correctly, this would have you at 6 ohms at the amp, and keep from toasting it. Someone still in the business, check me on that. After 24 years away from the audio business and not using the information, a lot of the previous info has leaked from the brain...kind of like the smoke from your amp.:p Jim.

[Matt Meiser]

8 ohm ceiling or outdoor speakers with the impedance matching volume controls. With those controls, you wire all the runs for each channel in parallel and the volume controls maintain proper impedance to the amp. There's a switch on each that you set based on the total number of speakers. Given that it had been on a few hours today and has probably thousands of hours of use, I guess I'm thinking it's not a problem with the speakers/wiring/controls but it certainly won't hurt to measure the impedance. I'll have to research how.

[John Coloccia]

I too am concerned about the impedance the amp is seeing. This is sort of typical behavior for a solid state amp when it sees too low of an impedance. Some amps will handle it, some will temporarily shut down (over current/temp circuitry), and others will simply blow up. I wouldn't want to see a replacement amp also blow up because of an impedance problem.

On a solid state amp, the impedance can be as high as you wish, but too low is extremely bad.

[John Coloccia]

8 ohm ceiling or outdoor speakers with the impedance matching volume controls. With those controls, you wire all the runs for each channel in parallel and the volume controls maintain proper impedance to the amp. There's a switch on each that you set based on the total number of speakers. Given that it had been on a few hours today and has probably thousands of hours of use, I guess I'm thinking it's not a problem with the speakers/wiring/controls but it certainly won't hurt to measure the impedance. I'll have to research how.

I'm trying to remember how these controls work, but I recall that a common error is setting the controls for the number of speakers on that one control as opposed to the total number of speakers on a particular channel. Also, people not realizing that left and right outputs are two separate channels.

[Larry Edgerton]

I have had great results in my own house and customers homes with Luxman amps, but it has been a few years since I looked at what they have available. They are designed for just such an application. I have about 15 years on my present system and other than replacing the CD player no breakdowns.

Larry

[Matt Meiser]

I'm trying to remember how these controls work, but I recall that a common error is setting the controls for the number of speakers on that one control as opposed to the total number of speakers on a particular channel. Also, people not realizing that left and right outputs are two separate channels.

OK, so I just took a mid-morning break and pulled out each volume control. They were all set on the "X2" setting which would present a 4 ohm load to the amp. Except for one that was still on X1. As I understand these to work, on X1 (assuming 8 ohm speakers which is what I have) they appear to be 8 ohms. x2 is 16, x4 is 32 and x8 is 64. So I had 3 @ 16 and 1 at 8 which would end up as a 3.2 ohm load to the amp. The amp is rated for a 4 ohm load minimum. I'd blame the installer but I don't have a mirror handy.

While I had each out I just switched it to the x4 setting since this is basically for background music and we don't really need a ton of volume and this should give the new amp a lighter load to carry. If we aren't getting enough volume I'll change them back to x2.

So back to my original question...

The current amp is an AudioSource AMP102 50Wx2 @ 8 ohm, 75Wx2 @ 4 ohm. Maybe I should just replace it with another. I did hear back that repair is a flat $115. Shipping would add $25 or so since they are in Oregon. That's not much less than new and new has the 2 year warranty.