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I plugged my phone into my integrated amp using rca jacks into an auxiliary in back. After a few minutes of medium volume listening my speakers blew. Amp is MOON I-3 and speakers are totem hawks. What did I do wrong.
Follow Ups:
I notice when listening to the stereo in my car that if the volume on my iphone is too high, the result is very nasty distortion, and this has happened with the 4S, the 5 and my present SE. Perhaps you had the volume way way up on the phone and overmodulated to the point where there was damage?
It's a shot in the dark...
Hey there,
Do you remember which input you used? I'm not 100% sure on the Simaudio I3, but I know the I5 and many of the Simaudio integrated amps used one of the inputs as a "passthrough" input - one that bypassed the preamp gainstage entirely. This was for people who wanted to incorporate an outboard surround processor/preamp or run the outputs of a surround receiver through the system.
If you ran a phone through a bypass throughput, it's very possible that a signal went through at full gain. That could have damaged speakers without showing any immediate damage to the integrated.
Again, I'm not 100% sure but I was a dealer for Simaudio years ago (during the era of the I3 and I5) and am a long time Simaudio owner myself.
Do you still ave your owners manual handy? We could confirm if you do.
Regards,
Shaun
I suspect one of two things happened.....
1. The phone's output sent DC (offset) into the integrated amp, and then something in the amplifier ultimately failed, sending nasty DC (not related to the phone signal) to the speakers, frying the voice coils ("seized").
2. The phone's output put out excessive RF (leaking from the digital circuitry) into the amp, and some transistors (especially FETs) are known to fry if excessive RF is present in the signal. (I think the SimAudio MOON I-3 is a solid state integrated amp. I recall stories like this with early CD players driving solid state amplification.)
Or maybe a combination of the two.........
A cell phone is not really made to be used as a source component on a high-end audio system......
Clipping distortion can be bad for speakers. Perhaps you overloaded the amp's input?
Good luck ,
mark
The Hawk is rated to take up to 120 watts. Your amp will likely do 130 into 6 ohms. Speaker manufacturers are always conservative with power ratings. I've easily put often twice the rated limit into speakers but with a solid state amp it must be all but distortion free. Being at both the amps max power as well as the speaker's rated max is a recipe for trouble. Especially with a small woofer and a speaker that's only 86dB efficient. If you froze the driver the voice coils are burnt. This most likely happened from overdriving the amp to distortion. Clipping a solid state amp basically puts DC on the voice coil and heats it up and poof. Bass heavy music with that small woofer is also tougher. We would put the NAD 200/ch amp on little PSB Alpha minis and Kirksaeter 60's with small woofers without a problem with non bass heavy music. We were putting at least 2X their rated power but it was clean power with no clipping.
ET
"If at first you don't succeed, keep on sucking till you do suck seed" - Curly Howard 1936
Edits: 01/19/17
Good question about how this happened given the low voltage output of a phone. But did you feed a digital (wrong) or analog (right) signal from your phone to the preamp in the integrated? Did you feed a line preamp input (right) or a phono input (wrong) on the integrated?
I'm not sure what would happen if you got either of these wrong.
DC in the feed (for some reason) from the integrated to the speakers may be the actual culprit.
in college. There was a loose fuse in the amp and now and then it would disconnect/reconnect, essentially creating a DC current (according to the tech back then) and frying a woofer or two. After a couple of reconings the problem was found. Still have the speakers but the amp is long gone.
There may be an issue with the cable or perhaps just a misconnect when plugging it in. Having you used this cable previously or since?
Regards,
Steve
Saw an Adcom 200w channel amp do this to a pair of Boston Acoustic A200. No phone involved. Tech said DC went thru the system which immediately froze the woofers. The mid & tweets were saved by the crossover caps. Amp protection circuiry should have stopped it, but didn't. We didn't hear a thing. Felt bad for the dealer doing our demo.
I was also thinking of a DC leak.
Very strange. From the posts below there's nothing apparent you did wrong. But a question: to get to the "medium volume" you describe, what position was the volume control on the Moon? Cranked way higher than when you listen to CD's, perhaps? If you had the output volume of the phone much lower (and subsequently less voltage output than a standard line level signal) and compensated by turning up the volume on the amp, it's conceivable you could have driven the amp into clipping, even though the overall perceived volume was "medium." Just a guess -- I have no experience with either your amp or your speakers (although I do have an iPhone). :)
It doesn't have a control knob but vol up and down buttons. It goes from zero to 50. I normally set between 27 and 32 depending. Don't remember what it was set at exactly. Thank you for all responses.
Which phone was it? Brand / model ?
It was a iPhone 6s. Do you know if drivers can be replaced without getting them from totem?
I'm not familiar with the speakers but doing a quick search on the net it does look like there may be replacements available from other companies. At the same time I came across some discussion that replacement parts direct from Totem are reasonable. Perhaps if you explain the situation to Totem it could work out for the best.
Good luck with everything.
Cheers!
Jonesy
"I know just enough to get into trouble. But not enough to get out of it."
Interesting. I have the iPhone 6s and have successfully used the 3.5mm analog output with a splitter cable much like yours w/o issue in a car audio setup and through my Rogue integrated amp in the basement.
I don't know what drivers totem uses. I don't know if they are proprietary and built by or spec'd by totem or if they are more readily available 'off the shelf'. In any case, hope you get them fixed.
Does the amp happen to have a "pure DC" mode ? If so maybe there is DC coming out of the phone.
Good point.
Since the Rogue is a tube amp I would expect interstage coupling via capacitor or transformer plus the audio transformers on the output. So there are a few places where any DC offset would be eliminated.
I never thought to measure for DC output from my iPhone. I suppose I could with a DMM or my scope. Have you tried measuring?
Don't think DC is the problem.
You did nothing wrong. I used a cable that had a stereo mini plug on the phone end and RCA's on the preamp end for years. Virtually identical to the one you showed. Never ever had any issue and I cannot think of any reason why it should've caused the failure you experienced. It may just be coincidence.
Need more info on the smartphone and cable you used.
I can't see the speakers blowing ahead of a protection circuit or fuse in the amp.
Check the amp and speakers and at least see if you can get them working again.
Then provide the info on the smartphone and cables. Also which jacks exactly did you plug into on the amp. If you say "Phono" than I assume you are just trolling?
Cheers!
Jonesy
"I know just enough to get into trouble. But not enough to get out of it."
I plugged in a set of garbage speakers and they work. The drivers in totems are completely seized. This is a photo of cables. Not sure what trolling is.
If you tried other speakers, and they work, the phone may have been sending a high level of DC (offset), which in time melted the Totems' voice coils........
Thank you everyone. I ordered the replacement woofers. Can anyone tell me how to test the signal coming from amp before I plug speakers back into it. Maybe some meter I can buy and what I should look for. Thanks again everyone.
If you're in the US, Harbor Freight has little DVMs for about five bucks. Sometimes they give them away with the purchase of something else.
First thing to do is check and see if it reads zero with no input, and bring some kind of battery with you to make sure it actually reads. Do this in the parking lot, if it is defective they will replace it immediately.
As far as checking it, that is a little bit more tricky. With the woofer still out, find some program material with practically no bass and set the settings where you had themm when the woofer fried. The reading will fluctuate but that little minus sign at the left should be on and off about equal times. If it is always positive or always negative that means there is DC on it.
The reason to find something with no bass and actually have the gain up is because the circuitry in the phone might be like in a hearing aid, strictly single ended. They do this because of the lower component count and the speaker in the hearing aid provides for an inductive load. going into electronics the load will be resistive, but is usually capacitor blocked so at DC should be higher. you don't have the means to actually measure the input impedance of the amp though so it has to be done in a roundabout way.
With a (the) cable, two capacitors and four resistors a DC blocker can be built in minutes. anyone who works on electric guitars should be able to do it so a music store might be the idea here.
Another thing is if the amp does have a "DC" switch you can just set it to OFF, however if it ever gets inadvertently bumped into DC mode again you'll have the same problem. An ounce of prevention is better than pounds of speakers.
Would you be able to post of pic showing the jacks you plugged into.
On the moon amps, sometimes a pair of the input jacks have the letter "p" next to them.
For example you would have A1 A2 A3/P.
This last one is intended for phono (turntable). Plugging into there could create havoc.
Cheers!
Jonesy
"I know just enough to get into trouble. But not enough to get out of it."
Plugged into a1
The cable you showed was multicolored but the cable connected to CD on the amp is all blue. Two different cables?
Bill
The ones plugged in back are for my CD player. The ones in my hands were the ones my phone were plugged into into a1.
Was hoping to spot something obvious, but as one of the other posters said, doesn't look like you did anything wrong.
Unfortunately you've now got fried speakers.
Really surprised that much power got to them to do that much damage without the amp shutting down first. And it was both speakers.
Almost sounds like the cable end that goes into the smartphone shorted out. Or the jack in the smartphone itself is faulty.
Jonesy
"I know just enough to get into trouble. But not enough to get out of it."
Are you sure you fried the speakers? Plug in earphones to hear if they work. Check fuse in your receiver. If you didn't turn everything off before plugging in the phone, you could have blown the fuse. Boy do I doubt you blew the speakers.
Amp is still working. Sound still coming from tweeters. Both drivers are frozen solid. Pushed one in and it made the worst crunchy sound I have ever heard. They're definitely toast.
.
No I didn't. Someone told me I needed a DAC but someone else I know doesn't use one(different model amp) and they have had no trouble.
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