Is my amplifier going?

CinderLyon

I have some brand new RtiA9's that I have connected to an 20 year old Adcom gfa-555 amp. I swear i hear cracklingsounds much like a paper read makes out of one channel but only at certain high band frequencies. Usually I hear it at about the same frequency ranges as a snare drum stick circling on a High hat would sound. The sound is intermittent over the course of a track, but reproducible at the same point in a track when it shows up.

I have tried swapping speaker sides, and wires. I have cleaned out my amp. My amp cleaning actually made the low level static i used to hear when no music was playing go away. That was cool. I am replacing all my banana plugs. The wire is 20 year out fat monster cable. I suppose i could cut off the end of the wire and start with fresh when i replace the bananas. I know this is funny but when i turn my back to the speakers I don't seem to notice it at all which has me thinking it might be environment or a rattle in my head lol.

So what else can i do? Is this a symptom of a amp going? For all i know it could be something in the environment. I have moved lots of things around.

F1nut

It could be that the amp is being overdriven trying to drive those speakers and sending a clipped signal and/or perhaps the caps are going bad in the amp.

tonyb

Either the amps going or your hearing....one of the two. :biggrin:

Seriously, on a 20 year old amp, the possibility of some refurbishing is very real. On the cheaper side, I would first knock out any possible cable issue by trying some others you may have laying around.

Or your seriously pushing it to it's limits Mr. sticky fingers, turn it down a notch.:biggrin:

CinderLyon

i am playing at about 70-75 db. I really dont like loud music

F1nut

What are you using for a source?

hertz9753

I was thinking the same thing.

BlueFox

CinderLyon wrote: »

....I have connected to an 20 year old Adcom gfa-555 amp.

Going, going, gone.

jeremymarcinko

If your using the onkyo in your sig. As the pre. try turning off audyssey and all other post processing. My older onkyo 705 makes all kinds of strange noises with audyssey enabled

CinderLyon

going going gone is not very helpful. I was looking for ideas on tests of how to tell if it is going or not. or things to try. or if anyone knows if this is a symphony of a amp going. I did some research on amps wearing out and never saw a mention to the symptoms.

F1nut

What is your source?????

CinderLyon

I am using an new Onkyo TX-NR809 receiver and I would suspect the new receiver, before the amp.

F1nut

That's not your source. A source is a CD player, iPod, computer, etc.

CinderLyon

What do you mean by source? 192k sample rate type of thing? Been using internet at 192kHz. I will try some telarc CD's and see if it is reproducible. Good point.

BlueFox

CinderLyon wrote: »

What do you mean by source?

Where is the music coming from?

F1nut

Been using internet at 192kHz.

So, you are using your computer. I suspect that's where the issue is. Yes, please try your CD player and report back.

CinderLyon

ok this was fun I plugged in my cd player, something I have not done in over 5 years. I have been happy with my computer being the source for a long time given that I did not have my higher end equipment available to me due to living situation. First thing I noticed is I had a hard time getting my cd player to close. One of my all time favorite CD's was stuck in it. I had been looking for that sucker. Then I noticed that my CD player was SACD capable! woot!

Ok so back to the issue. I may have been sensitized to listening for the funny sound so I kept thinking I was hearing it, but less so. So I gave it sometime. Then I decided to bypass my amp. And I still thought I was hearing it. That was good actually. I could rule out my amp. woot! Then I decided to move the one speaker over a bit. That seemed to help as well. Then I tried to listen to the same track on my computer and it seemed worse, so I swapped in and out of sources for a while. It was a bit worse on my computer and it showed me just how good my CD player is! woot!

Back on my computer now and it does not seem as bad, hardly even noticeable really now. Moving my speaker seem to be the best solution so far. I will have to give it some time and more different music test to know for sure.

Thanks guys for pointing me in a good direction to test. I am convince that my amp is just fine now.

So now i get to spend my hard earned money on a good sub.

Bob in WI

If anyone here can figure out the masked effects of room acoustics, they are better than I am. Glad your issue is solved (maybe).

CinderLyon

Ok I finally figured out what was going on and as you can see from this thread it took awhile to isolate. My brand new receiver was bad. It was putting out low level static in the mid-fq on note decays. I tried everything to figure this out. It finally dawn on me to unplug everything from the back of the receiver except one of my surround speakers and use it as a left channel. And by pass my amp going direct to the receiver. I also used a CD player as a source not my computer, just in case. Low and behold static in the mids still. and much easier to hear on a smaller speaker than my A9's.

CinderLyon

Well I was wrong. replacement receiver showed up and I still have static on some of the higher end mids.

I think I am down to to much gear hitting wiring in an old house. I failed to mention that the static shows up when the speakers are under load. So I am getting a power conditioner. I hope this does the trick

tonyb

A good power conditioner may help, but please also explain how your rig is setup with the computer for audio. That may be a contributing factor too.

jeremymarcinko

Ground your receiver if you haven't already. I had some static(not much) on my left main, never minded it but when I added a new amp I was getting a ground loop hum. I was advised to ground the receiver it fixed the hum and no more static. Also have you replaced your terminal jumpers with copper wire? The binding posts don't seem to stay very tight on the jumpers and have caused a static issue for me as well.

CinderLyon

tonyb I get the static no matter the source, direct from CD player or through my computer or through my old preamp (need to recheck this one). And adding the power conditioner did not do the job
I have another test I am going to try.

I am begging to wonder if maybe my speakers got damaged in shipment.

CinderLyon

termanal jumpers have been done with wire. As far as grounding my receiver goes it is grounded by 3 plug power cord at the moment. I would think that would do the job.

CinderLyon

when I run audiophile test disk 3 track 16 harmonic series, I get two clicking sounds on both speakers on one of the lower mid tones. Does anyone know if this is in the recording?

CinderLyon

well I verified that the ticking sounds is in the data for test disk 3. So that did not help. still working on this

jeremymarcinko

CinderLyon wrote: »

termanal jumpers have been done with wire. As far as grounding my receiver goes it is grounded by 3 plug power cord at the moment. I would think that would do the job.

Doesn't the 809 only accept a 2 prong cord?

If it's like my 717, I grounded it from the ground screw on the back panel, with a wire to the ground screw on the power conditioner.

CinderLyon

the 818 has a 3 prong cord. i put on an extra ground wire between the phono ground on my receiver and my power conditioner just to test anyways.

As part of this whole thing I replaced my 809 thinking it was defective. I upgraded to an 818; need to fix my signature. the 809 has 3 prongs as well as i recall.

I am now wondering if I am hearing clipping. Going to test some CD's with my old analog preamp next (again).

tonyb

A clicking sound ? Are you using bare wire connections into the binding posts on either the speakers or receiver ? If so, wire may be touching another post or wire. Make sure, double sure when you put the bare wire into a post it doesn't touch any other wire or other post. You said you have wire in place of the jumpers, check that too.

CinderLyon

all my wires are terminated with banana plugs. the only bare ended wire at the moment i just added and it is the grounding wire i tried. but thanks for the suggestion.

CinderLyon

it sounds more like an diminishing buzzing, low level, that decays accompanying and after each strong multi frequency passage. low level static really. Some times on strong note attacks as well.

tonyb

Could just be a standard ground loop problem too....or a bad interconnect cable. Have you tried disconnecting the sub from the receiver and see if the sound is still there ?