AR90 help needed

[SteveS]

After restoring my AR90's (I did not replace anything in the crossovers) I started enjoying them last night. Near the end of side one of an LP, the left speaker seemed to just go dead. Upon inspection, it was still receiving a signal, but was muted. Turning the balance all the way to the left, I could hear a faint reproduction of the music. After about 30 seconds, the speaker came back to life. I listened for about another 2 hours and it did not happen again.

This morning, I had them playing about 2 hours. Everything was fine.

This afternoon, I turned on my stereo, and immediately the left speaker was in it's muted stage. After about 1 minute, it came back to life, and John Hiatt sounds great as I type.

Any guesses?

Thanks a bunch

SteveS

[dynaco_dan]

>After restoring my AR90's (I did not replace anything in the

>crossovers) I started enjoying them last night. Near the end

>of side one of an LP, the left speaker seemed to just go dead.

>Upon inspection, it was still receiving a signal, but was

>muted. Turning the balance all the way to the left, I could

>hear a faint reproduction of the music. After about 30

>seconds, the speaker came back to life. I listened for about

>another 2 hours and it did not happen again.

>

>This morning, I had them playing about 2 hours. Everything was

>fine.

>This afternoon, I turned on my stereo, and immediately the

>left speaker was in it's muted stage. After about 1 minute, it

>came back to life, and John Hiatt sounds great as I type.

>Any guesses?

>

>Thanks a bunch

>SteveS

>

Hi Steve;

This is my best guess for now.

I have experienced channel dropouts on occasion and I found it was usually due to lack of use.

The pots on speakers sometimes do it as well.

If you un-plug the amp's AC and turn the volume, balance, treble and bass controls back and forth several times it should clean up the contacts.

I wouldn't use just any contact cleaner, if you should go to this next step.

Use Deoxit or the older name Cramolin is a sure thing.

Not cheap, but good.

This is probably more apt to happen around smokers and greasy cooking atmospheres.

Good luck.

[Guest GP49]

I would sooner think you have an amp problem than a speaker problem, since it's not just PART of the speaker that is not putting out, but the whole thing.

Do you have an amp (or receiver) where, after a few seconds from switchon, you hear a "CLICK" and the sound begins? If so, the relay that is doing the "clicking" may have dirty or burned contacts that need cleaning or burnishing. Often we are lazy and leave the volume turned up at switchoff. If at switchon there happens to be audio playing (especially if it is LOUD) when it is time for that relay to go "CLICK" there may be an arc across the relay contacts. Do this enough and you'll have burned relay contacts.

Some of these relays can be opened up and the contacts cleaned and burnished. Some of them need to be cut open to do this. Some can only be replaced.

If you do have an amp with a time-delay/protection relay like this, do yourself a favor. TURN THE VOLUME TO ZERO before switchoff, and don't turn it up until after that little "CLICK." And follow the advice from the previous post: every now and again, with the power switched OFF, turn every single control, and switch every single switch. You could save yourself the cost (or if you do it yourself, the hassle) of cleaning and lubricating the controls and switches.

[ar_pro]

Try swapping your left & right speaker cables, Steve. If the problem switches from the left to the right speaker, then you've eliminated the AR-90s as the culprit, and you should look closely at your amplifier and the integrity of your speaker cables & connections.

If the problem stays with the left speaker, double-check the jumper wires between the upper & lower binding posts.

[SteveS]

Thanks for all of the helpful hints. The dropout has now occurred in both channels, using both LP's and CD's for playback, so the AR90's are not the culprit. I'm pretty certain it is my preamp or amp, but I'll have to do some more testing to figure out which one.

Steve