[Nugent1021]

I have an Avalon NP subwoofer I bought a few years back. The amplifier is 300watts. It currently buzzes on "on", and it appears the "auto" feature has stopped working. I have it on it's own outlet separate from the breaker for the rest of the system, and it continues to buzz when I disconnect the sub RCA cable. I've been in contact with Avalon, and they let me know it's out of warranty. I haven't been able to find out the type of amp (to buy a replacement) or a possible fix. I don't have a problem with taking it apart, but I probably won't know what I'm looking at without a diagram or something.


Avalon says they've discontinued the NP series, but they have a few left and maybe we can make a deal. Considering it was a little under $2000 new, I'm not sure I want to just throw this away.


Does anyone have any idea what type of amp is in this, or an alternative (such as a website that may show me parts of the amp to test or fix)? These amps are really just large coils and transistors, it seems like.


Thanks for any help.

 

[Th3_uN1Qu3]

The amps are a bit more than large coils/transformers and transistors, but the parts you mentioned are usually those which blow.

What tone is the buzz? Does it not play any sound besides the buzz? It sounds like the final stage is shot. It's usually made with big power transistors or MOSFETs at this kind of power, so look for any burn marks on them.


You're not likely to find a diagram for it, so the only way is probably to grab a multimeter, check all transistors and ICs for shorts, replace what's blown and hope it works.

 

[Nugent1021]

The bizzing sound is constant, not real loud, but annoying and then it'll cut out once in while (maybe slightly louder right before it cuts out). I can flip the switch (auto/off/on) and sometimes it's red and sometimes it green (a little light next to the switch). I can't seem to influence the buzz by switches or anything, other than turning off. The buzz doesn't seem to have anything to do with the bass (it's not louder when the bass is lower or volume is louder) it's just a constant buzz when "on" or "auto".


I guess that makes sense, get out the voltmeter and start checking for continuity.


actually, on "auto" it will sometimes go "zzzZzz" (the capital Z was on purpose) and then stop buzzing. Then, it'll start up again soon enough.

 

[dmichael]



Quote:
Originally Posted by Nugent1021 /forum/post/15449807


Avalon says they've discontinued the NP series, but they have a few left and maybe we can make a deal. Considering it was a little under $2000 new, I'm not sure I want to just throw this away.

Not sure where your getting your information, but clearly you are mis-informed. It seems curious at best that they would quit on a line that just started about 2 years ago.


I called Avalon Acoustics to verify if the NP series is being discontinued, I spoke with the sales manager and he flat out unequivocally stated that they have no such intention to discontinue the line. Direct quote was "We have lots and lots of them and no plans to stop making them".

 

[Nugent1021]

I'm taking this subwoofer apart this week (yeah, I was delayed a while with work and a new baby) and I'm going to try to fix the internals. If anyone else has any experience or suggestions regarding the internals of a subwoofer amplifier, your knowledge would be more than appreciated.


As for dmichael, thanks for the reply and focusing on the single most unimportant and insignificant part of what I posted. I was told by the guy at Avalon that the NP series was discontinued. That's what he told me. Who cares anyway, a replacement would cost way too much.

 

[Noubourne]



Quote:
Originally Posted by Nugent1021 /forum/post/17347102


I'm taking this subwoofer apart this week (yeah, I was delayed a while with work and a new baby) and I'm going to try to fix the internals. If anyone else has any experience or suggestions regarding the internals of a subwoofer amplifier, your knowledge would be more than appreciated.


As for dmichael, thanks for the reply and focusing on the single most unimportant and insignificant part of what I posted. I was told by the guy at Avalon that the NP series was discontinued. That's what he told me. Who cares anyway, a replacement would cost way too much.

I disagree. In production means you can find a replacement amp quite easily - potentially from the manufacturer - and potentially for far less than the cost of a complete replacement.


The person you spoke with does not seem helpful. The person dmichael spoke with seems helpful. Perhaps you should try calling again to see if you can get anywhere with it? They may have returns or other sources of functional amps (if not used) that you could try to get your hands on.


Even if you found the right broken part, what are the chances that you'll be able to solder it all back together without damaging the rest of the board?

 

[Th3_uN1Qu3]



Quote:
Originally Posted by Noubourne /forum/post/17347422


Even if you found the right broken part, what are the chances that you'll be able to solder it all back together without damaging the rest of the board?

If he hasn't soldered before, not too high. Hint: A desoldering pump helps greatly.