[intamin22]

Ok, so I have two setups with my song towers. One ht with a ps3 to a marantz sr5002 to a rotel rmb1075 all plugged into an apc h15 power conditioner. I also have a nad m5, a parasound p3, and an audio refinement multi 2 amp for 2 channel, also plugged into the same power conditioner. (2 sets of speaker cables btw) A few weeks ago I unplugged stuff to try moving it around. No luck, so I put everything back to how it was. However, my 2 channel setup now has an occasional pop that comes through the tweeter. It varies which speaker it happens on. I don't have this issue with my ht setup. I've narrowed it down to it occuring as a result of the multi 2 (if I shut everything off but the amp I still get the pop). I don't think this is a ground loop issue, so I'm sort of at a loss. Could it be the amp is just going bad? Any help would be much appreciated! Thanks,

Alex

ps, sorry if typos I'm using an iphone.

[oneinthepipe]

The amp should be the last component turned on and the first component turned off.  If you turn off your amp first, you won't have a pop.

[intamin22]

The amp should be the last component turned on and the first component turned off.  If you turn off your amp first, you won't have a pop.

The pop doesn't happen when I first turn on or off my equipment but during actual play back every so often. I'll try what you said though but if I recall that's generally the order I turn stuff on and off in.

Also forgot to mention that if I plug the amp in straight to the wall I then get a ground loop hum.

[ctviggen]

The first rule in debugging is to strip the system down to its minimal configuration and then if there's no problem, add items in one at a time (note that you might be able to debug both the ground loop and the popping at the same time using this method). 

First, unplug everything from the amp except the speakers.  Turn the amp on and see if you have any pops.  If no pops, plug in the preamp, connect it tot he amp, and turn it on.  Listen for a while -- any pops?  If no pops, plug in one source.  No pop, plug in another source, etc.  If the first source has pops, then you haven't necessarily ruled out the preamp or amp. Unplug the first source from the preamp and plug in a second source.  If you have pops, then it's not the source, it's the preamp or amp.  To test the amp, if you have a source with its own preamp (some CD players, Squeezebox, etc.), plug this directly into the amp and play.  If you get pops, you haven't ruled out that source, so use that source on a different amp and speakers.  If no pops, the amp might be bad.

I hope this makes sense.

[PMAT]

A spike in the ac from a bad light switch or fan switch can do this. Conditioners don't fix it. Is the same exact ac outlet being used as before?

[Wayner]

I have a room that has actually 3 systems in it. I have found that it is not wise to have both systems connected to the same circuit. I would try this as an experiment. Get another cheap power strip and plug just one of the systems into this strip and then try to plug the power strip into a different location (and better yet, a different 120v branch circuit. I believe that power supplies for the amps and preamps may be having an effect on each other.

Wayner

[charmerci]

I've had a pop come through my stereo when the refrigerator would turn on. Is it that type of time period? If it is try having someone turn the frig off and on while listening.

[intamin22]

Thanks for the help and suggestions! I'll give them all a shot. I have a freed up 20amp circuit now because my landlord took out the window ac unit that's in my room (Senior college student renting an extremely old house on campus); I'm hoping it's something as simple as just putting the 2 channel stuff on a different circuit.

[intamin22]

Ok, update on the situation. I put the 2 channel on a dedicated 20amp circuit. I then used only the amp and speakers, no pop. I added the preamp to the mix, and again no pop. I then added the nad m5 to the mix, and got a huge pop after about 5 minutes. This pop was much louder than what it normally was when I had everything through the power conditioner. So I unplugged the m5. I then grabbed a dvd player and plugged it into the system with the m5 unplugged. Again, no pop. This leads me to believe it's an issue with the m5. Aside from this pop, the m5 is making weird noises when I skip tracks on sacd's, so that just reinforces to me that it's an issue with the cd player. I guess my next question is where do I go from here? Send it back to NAD and have them try to repair it? I purchased it used from agon so no warranty. There is also a local repair center nearby that is supposed to be good, would that be a better route? Thanks again everyone!

EDIT: Spoke too soon. After about 30 minutes of having the dvd player in and on I got a small pop. So I guess I'm back to square one ><

[oneinthepipe]

Nevermind.  You posted about the continuing noise while I was writing.

[Wayner]

Now it's time to start looking for small appliances (or even a furnace) that is kicking in or out occasionally. Motors can cause this especially. Also some fluorescent lighting turned on and off can cause a spike. Now I really think you are hearing a voltage spike.

Wayner

[intamin22]

Now it's time to start looking for small appliances (or even a furnace) that is kicking in or out occasionally. Motors can cause this especially. Also some fluorescent lighting turned on and off can cause a spike. Now I really think you are hearing a voltage spike.

Wayner

This wouldn't really surprise me given the age of the home. However, wouldn't I hear that with my HT equipment too, or maybe my HT equipment is better at managing the spikes or something? Unfortunately I have 4 other roommates so it's going to be hard to narrow it down if it's appliances or lights or something of that nature.. I think this may just have to be something I live with until moving out at the end of the school year. On a positive note, it's been 40 minutes since hearing any pop with having the dvd player in the system and the m5 out of it. I still think it could be an issue with the M5 and that the small pop I heard was a result of a voltage spike or just some other noise in the house that I confused with the speakers popping. So frustrating!

EDIT: I've got good news, we're extending arts and crafts time by 4 hours today! Err, I mean, I solved the problem! I have the preamp and amp plugged into a power strip that goes to the 20amp circuit, and the m5 plugged into APC power conditioner. I've had the equipment on for 2+ hours and not a single pop!

[intamin22]

Well, after my last post several months ago where I thought I solved the issue, it turned out I hadn't. I was frustrated and gave up on trying to solve it/figure out the source. Today, I finally got back to work in trying to find the cause. I've determined it is my audio refinement multi 2 amp causing a pop to come through the tweeters every so often. I have two separate set ups, one for ht, one for 2 channel. I unplugged my ht amp entirely. (I have never had an issue the popping on the HT side). I then put my Multi 2 into it's place, and made the same exact connections that my HT amp originally had. I then turned everything on as if to watch a movie. About 10-15 minutes later I got the pop. This has never happened with this set up. The only thing to change were the amps. Now that I've isolated the issue to it being my amp, where do I go from here on remedying the problem? Thanks, and sorry to resurrect this old issue, but maybe this can serve as a deterrent from the Lexicon/Oppo drama

[Nuance]

If you are positive its the Multi 2, contact Audio Refinement to inquire about warranty and any costs to you.  You could also look for a used amp on audiogon. 

http://www.audiogon.com/cgi-bin/cls.pl?ampstran&1267217708&/Parasound-2250-
http://www.audiogon.com/cgi-bin/cls.pl?ampsmult&1269022246&/Ati-1504-220V-Ser-50-4ch-x-150
http://www.audiogon.com/cgi-bin/cls.pl?ampstran&1267765983&/Rotel-RB---1070-Solid-State-Am
http://www.audiogon.com/cgi-bin/cls.pl?ampstran&1266796350&/McCormack-DNA-0.5-Power-Amplif
http://www.audiogon.com/cgi-bin/cls.pl?ampstran&1269029142&/Outlaw-M200-%283%29-Monoblocks
http://www.audiogon.com/cgi-bin/cls.pl?ampstran&1268929076&/Musical-Fidelity-XP-200-Power-
http://www.audiogon.com/cgi-bin/cls.pl?ampsmult&1267900310&/NAD-T955-Amp--New--with-Warran
http://www.audioadvisor.com/prodinfo.asp?number=PAC2125

The list goes on and on.    I hope you get this matter sorted out quickly and efficiently. 

[intamin22]

Thanks Nuance. I don't think Audio Refinement is still around, I purchased this used back in June from Agon actually. I'm sorta wondering if this will be an issue that will be tough to repair or not. There's a local place that charges $100 hr, so at that rate if it's going to be a lot of work, I'd probably be just as well off getting a new amp. Thoughts on the type of repairs that may need to be made?

And I'll definitely look over that list Nuance I always do like having an excuse to by a new toy!

[taoggniklat]

Thanks Nuance. I don't think Audio Refinement is still around, I purchased this used back in June from Agon actually. I'm sorta wondering if this will be an issue that will be tough to repair or not. There's a local place that charges $100 hr, so at that rate if it's going to be a lot of work, I'd probably be just as well off getting a new amp. Thoughts on the type of repairs that may need to be made?

And I'll definitely look over that list Nuance I always do like having an excuse to by a new toy!

Just don't get that McCormack amp...I want it.