Can anyone help solve a scratchy tweeter mystery?

[futureman]

Recently, I noticed the left channel tweeter sounding 'scratchy' or fuzzy when the music was hitting higher frequencies. On a whim I switched the speakers cables, and the static was now coming from the right channel. So it doesn't appear to be a speaker issue. Nothing changes when I turn off the EQ either (in terms of the scratchy sound).

Anyone encountered this problem? I'm using my Onkyo receiver (1977-79) as a preamp. I doubt it has had ever caps replaced. Perhaps that is where the problem lies?

Apologies if this belongs in another forum. But I did at least initially think the issue was speaker related.

EDIT: Can't seem to duplicate the problem with every piece of music, if this sheds any light at all on matters.

 

[cablephil212]

So, you've eliminated the speakers Let's move on.

Have you tried different speaker wire?

Have you hooked up another set of speakers (if available)?

This would be the steps I would take to narrow down where the problem lies.

If you can repeat the "scratch" with either of the above, then I'd say it's either the pre or amp is the problem.

Try the steps above, and report back.

Good Luck

 

[futureman]

Thanks cablephil. I recently had the amp updated and modded, so I'm hoping it's the preamp. I'll know soon enough, since I'll getting a Kenwood Basic C-2 at the end of the month.

 

[futureman]

Update:

Ran the music through the receiver alone. Same problem. This suggests that it's the receiver's preamp and not the speakers or the maggie amp. This will all be verified when I run everything through a new preamp.

 

[cablephil212]

Sorry to Hear That

Well, sorta good news, and not so good news.

At least it's not your power amp or the speakers.

The C-2 is very nice, and hopefully it'll get you back to your music.

It sucks that you'll have to wait. Hope everything works good together.

 

[musichal]

Update:

Ran the music through the receiver alone. Same problem. This suggests that it's the receiver's preamp and not the speakers or the maggie amp. This will all be verified when I run everything through a new preamp.

I assume you did try more than one source? This would rule out a flakey interconnect or even a tuner issue - though I doubt you were usng FM - or a TT/cart problem, etc. Dumb question, but sometimes we can overlook the obvious when trouble-shooting. De-oxit switches on the receiver?

 

[gadget73]

try cleaning the switches and controls maybe. I'm assuming your 6500 has a high filter switch like my 4500 does. If that or the loudness switch is dirty it might cause some static.

 

[futureman]

Yeah. Static coming through on certain frequencies using both the TT and CDP. Noticeable only on certain songs and certain albums, though. I assumed initially this was due to deficiencies in the vinyl, but started to wonder when I heard similar scratchiness on a few CDs. I cleaned some switches and controls to no effect. I did not try to clean the filter and loudness switches, however.

In any case, it's definitely coming through on the left tweeter, and it comes through the other tweeter when I switch the wires. I ran the music through the receiver to eliminate the tube amp as the source of the problem.

I didn't really notice an issue until recently. My fear was a bad tweeter or an issue with the recently acquired tube amp--or perhaps the tube amp generating a problem in the tweeter. Again, I *think* I've eliminated these as culprits. If the problem is the preamp in the receiver, I'm less concerned.