[ricmon]

Frank I just wanted to get your take on this.  I have a pair of very beautiful sounding speakers.  Some times I like to crank up the volume.  But never to the point where the speakers are just distorting and making sounds other music.  The problem is that I have gone through 3 tweeters and the manufacture is saying that my amp (550EXR / TR7) must be sending some inaudible distortion to the speakers thus frying the tweeters.  Can this in fact be happening or should I be looking to replace my speakers? 

Thanks Ric

[jeffreybehr]

Ric, don't you think it would be useful to include some info on your speakers?

[ricmon]

Ric, don't you think it would be useful to include some info on your speakers?

True.  I was just trying to get an general idea of what Frank thinks about speaker amp interaction and blown tweeters.  The speakers (could have looked ad my system link) are Lipinski L-707's

[avahifi]

The 550 has a flat bandwidth out to 100K Hz and clips very gracefully, just starts rounding off the waveform at clipping rather than doing nasty things.  So our modern equipment, DAC, preamp, and power amp will not generate tweeter blowing signals themselves.  However if something else in your system is generating a high frequency signal that could hurt a tweeter, our equipment will pass that signal along, and that might be the cause of your damage.

I hope this is useful.

Frank Van Alstine

[TomW16]

However if something else in your system is generating a high frequency signal that could hurt a tweeter, our equipment will pass that signal along, and that might be the cause of your damage.

Hi Frank,

If Ric is using a T7 as a preamp, doesn't it filter out anything above 20 KHz so that only the audio band is passed on to the amp? 

I use a passive preamp and often wonder what ultrasonic signals I may be passing along to my AVA 350 amp.  Luckily, I have never run into Ric's problem and my system sounds absolutely wonderful so I try not to think about it.

Cheers,

Tom

[ricmon]

The 550 has a flat bandwidth out to 100K Hz and clips very gracefully, just starts rounding off the waveform at clipping rather than doing nasty things.  So our modern equipment, DAC, preamp, and power amp will not generate tweeter blowing signals themselves.  However if something else in your system is generating a high frequency signal that could hurt a tweeter, our equipment will pass that signal along, and that might be the cause of your damage.

I hope this is useful.

Frank Van Alstine

Thanks for the reply.  The only other devices in my system are a Creek CD-50 Mk2 cd player and a subwoofer.  Thats it!

[Watson]

It's possible your amp is malfunctioning and generating high-frequency oscillations.

[ricmon]

It's possible your amp is malfunctioning and generating high-frequency oscillations.

How can I determine if this is happening?

[yeldarb]

If your sub has an amp with switching power supply it can generate all sorts of trash noise into your system. 

[ricmon]

It's possible your amp is malfunctioning and generating high-frequency oscillations.

If my amp is causing the problem how can I find out and what can be done to fix it? 

[avahifi]

We will certainly thoroughly test your amplifier if you wish to return it to us for inspection.  Given the issues you have had, we will not charge for testing, only for return shipping.

Regards,

Frank Van Alstine

[Wayner]

What position would you say your volume control is at when you like to "crank up the volume"? What style of music do you like to listen to?

W

[richidoo]

I have blown ribbons on weak tube amps which clip due to low impedence of speakers, I never knew it because the clipping was gentle, but enough to bend the ribbons elements. I have also had them blown by an oscillating amp, that was not gentle and I hope I never see that again. 

A good designer does not make oscillating amps, so I would doubt that is the problem. Remember Frank invented the infinite slew rate, so I think he can make a circuit stable to RF. If the sub is more than 2 feet away from the amp I would rule it out altogether.

The speaker is a normal load 90dB, 4ohm nominal, dipping only to 3.3 ohms. The 550 should not have any problem drive those speakers even at very high volumes. But you never know what's really going on unless you look at the output. It is just a machine, things can break.

Franks offer to check it out for free says a lot, doesn't it?? That combined with Brian's preamp review has got me looking for my wallet. Dang, still empty! 
Good luck Ric!

[warnerwh]

Tweeters can't take much power. It would be easy with that amp to over power alot of speakers and blowing the tweeters even if the amp isn't clipping.