[saneguy]

Hope your issues are resolved guys!
My left active speaker hardly produces any sound....only the right speaker seems to be working.
I think it might have fried its amp....Contacted support. lets see!

 

[bigcookiemon]

I notice the popping noise from my 5 yrs old A5 since 4-5 months ago, which once it was so notable when my PC & TV's was totally off and non stopping pop*s was there during my reading.

I find there was people saying change power cable.,. turning the volume knob all the way a 100 times....and thinking to open up and check if any noticeable dry caps or something.

finally someone was talking about wifi rounter.. and it really was the popping source.! problem solved for 4days already with quiet.

 

[RamblinMan1885]

Had the same issue with a set of these. I opened it up and found that a number of vias on the audio PCB were looking really bad. Poor connections could certainly lead to the circuit picking up electrical noise.

After touching them up with some solder, the popping and crackling has gone away. It was either the soldering or working the volume knob as I was troubleshooting.

Good luck!

 

[craycrayfrog]

Had some progress!
I’ve been working on a broken set of Audioengine a5 (old) with the symptom that one channel sounds better than the other.

The issue seems to be the op amps on the pre amp board fail over time I found the issue to be a single ne5532 which was covered in black adhesive which restored the right channel after swapping for another ne5532 on the board. On the amplifier board everything seems to have voltage but there doesn’t seem to be any amplifying taking place which leads back to what everyone else has been saying about the TDA7294 amp chips failing, though it could still be the preamp board at a low level.

For my attempt to repair this I’m intending to replace these systematically so I know where things have failed but replacing all the active chips including the jrc4558 op amp, all 6 of the ne5532 op amps and the 2 tda7294 amplifier chips.

When I’ve used my component tester on the tw bor electrolytic capacitors they have good values and actually have closer to spec capacitance and esr values than the new farnell bought Panasonics I was going to replace these with.


I didn’t find this work easy in fact I’ve stored these for 12 months while I get more equipment like a component tester, ts100, leaded solder with a lower melting point, 858d hot air station and a microscope.

 

[octil]

craycrayfrog, have you had any further progress? A few years ago my A5 intermittently started making scratching noises in the left channel. I've opened it up on the bench twice to try locating the problem, but each time I was unable to get the speaker to malfunction, so I've been unsuccessful in localizing the noise source.

While open on the bench I wiggled and poked connectors, components, solder joints, and everything seemed solid and didn't provoke any noises. The noise also seems to be more frequent when the temperature is warm, so I might try hitting parts with a hot air pencil. Whether the volume knob is at one extreme or the other doesn't change the noise volume or likelihood, so it's coming from one of the later stages.

The noise isn't overbearingly loud, so I've put up with it for a while, but it does get annoying. The electronics don't disassemble nicely, so I'm trying to be as noninvasive as possible. If anyone has nice internal shots of the boards and traces it would be helpful for doing a bit of reverse engineering before making another go at repair.

 

[octil]

I've gone for a more dedicated go at resolving the noise issue. Long story short, I suspect the issue I and others have had is due to thermal fatiguing of joints on boards (as RamblinMan1885 has suggested above). This would also explain slightly varied symptoms. Overall quality control of the boards is poor.

While open on the bench the noise was very infrequent, thus hard to localize, but I was able to determine the noise originates from the preamp board that all audio inputs feed into by witnessing noise being outputted from this board while isolated from the power amp board.

I removed the board, and in order to better examine and image the board I cleaned off the majority of the black elastic compound with fiberglass/wooden rods, desoldered large components, and cleaned the board with solvent followed by 15 minutes in an ultrasonic bath of alkaline electronics cleaning solution (Branson EC). Attached are images of the top (TOP.jpg) and mirrored bottom (BOT_mirrored.jpg) of the board. These have been formatted to perfectly overlap and allow the signals to be traced by opening these as separate layers in an imaging program.

I found multiple issues through examining the board:

• On the trivial end, reference designators for connectors alternate between "CH" and "CN"; perhaps this board was laid out by someone whose first language doesn't use the Roman alphabet, but it's a bit sloppy.
• While removing the black compound, soldermask came along with it in a few spots on both the top and bottom (see examples pointed out with red arrows in TOP_annotated.jpg). What is concerning is these areas are not bare copper, but coated in solder. This indicates the soldermask had poor adhesion and released either during application of HASL during board manufacture, or failed in subsequent soldering operations.
• The solder joins are a bit starved of solder (lead free is used). Of particular concern is the quality of some of the vias having a partial fill of solder, which through thermal fatigue can cause the connection to fail. One suspicious looking via is circled in TOP_annotated.jpg and shown under a microscope in via.jpg. This via also happens to be in a location that would perfectly explain the issue I've been having. I tried poking the center of it to elicit noise (resulting in the divot seen in the center), but didn't get any reaction. It's possible the cleaning steps could have temporarily fixed the joint.
• While the ("TBOR" brand) electrolytic capacitors were removed from the board I tested them and found the majority to be bad, with high ESR and low capacitance. These are mostly in locations of the circuit where this won't have much effect (like after the linear voltage regulators which are preceded by a large capacitance), and scratching noises from a bad capacitor would be very unusual.
• The voltage regulators 3U1 and 3U2 run very hot and without heat sinks, which is clearly visible in discoloration of the board at this location. These regulators are fairly robust and can operate this way, but capacitors 3C11 and 3C12 are right next to the regulators. These two capacitors tested the worst of all.

I'm going to replace the capacitors with quality ones and resolder joints that appear poor, and hopefully get quite a bit more life out of these. Without insight into whether Audioengine's quality control has improved, I couldn't justify ever purchasing from them again.

 

[craycrayfrog]

craycrayfrog, have you had any further progress? A few years ago my A5 intermittently started making scratching noises in the left channel. I've opened it up on the bench twice to try locating the problem, but each time I was unable to get the speaker to malfunction, so I've been unsuccessful in localizing the noise source.

While open on the bench I wiggled and poked connectors, components, solder joints, and everything seemed solid and didn't provoke any noises. The noise also seems to be more frequent when the temperature is warm, so I might try hitting parts with a hot air pencil. Whether the volume knob is at one extreme or the other doesn't change the noise volume or likelihood, so it's coming from one of the later stages.

The noise isn't overbearingly loud, so I've put up with it for a while, but it does get annoying. The electronics don't disassemble nicely, so I'm trying to be as noninvasive as possible. If anyone has nice internal shots of the boards and traces it would be helpful for doing a bit of reverse engineering before making another go at repair.

Unfortunately not. I had a set of broken a5 speakers and a spares/repair one off ebay. The set had zero sound and the one off ebay quiet with no amplification and super noisy. Where the black adhesive was around the ne5532 they had failed and the adhesive was burned underneath, I proceeded to remove themove the adhesive with a 858d hot air station and tweezers which did an excellent job no damage to the solder mask or components. I couldnt find any missing connections on the amplification board and the signal on the mute pin seemed fine(it was ages ago dont remember what I read). I tried replacing the tda7294 but when I plugged in and tested with everything connected I got smoke around one of the capacitors however rather than carrying on the project I swore a bit and converted these to passive speakers using the stock crossover using the below Nobsound NS-04G
https://www.aliexpress.com/item/1005001631970703.html?spm=a2g0o.order_list.0.0.710c18025bX10r

Honest opinion these speakers dont sound amazing on my desk as the tweeters dont play much of there range. Looking for the next set of speakers for my desk atm and want something equivalent to the below QTX 2.25" 40w mylar tweeters
https://www.ebay.co.uk/itm/234167579676.

 

[octil]

Converting these to passives seems like the right thing to do. Having gone through this, I'd not recommend spending time to repair. But I'm stubborn, and did manage to get these working well.

After reflowing all vias on the top (if not covered with a component) and bottom with 60/40 Sn/Pb solder and replacing the bad capacitors, I then had issues with the right channel. Whether the 3.5 mm jack on the back or top was used, the audio was intermittent, and the issues were easily found by poking around with a fiberglass rod. In both cases, one of the solder joints of a surface mount inductor near the audio input was cracked (different inductor for each input jack, but coincidentally the same problem on both). After reflowing these and banging around the board some more before reassembly to listen for issues, I reassembled and have been using the speakers heavily for the past week and a half with zero issues. It's very possible I'll have more fatigued joints to fix in time, so I'll ditch these once it ceases to be a quick to locate fix.

 

[dekaliber]

Glad I came across this thread. I had replaced my A5 speakers with a pair of PSB Alpha AM5s due to the same issues ("blowing into microphone" sound is the perfect description) but decided I would hang on to them to see if I could tinker with them and potentially repair them as a set of speakers for my garage. It's worth mentioning that I've also gone through TWO Audioengine S8 subwoofers for what seems to be a very similar issue. Obviously never buying anything from Audioengine again since 3 of 3 products I've purchased have failed in some way out of warranty.

For me, the scratching and popping sounds were almost exclusively coming out of the non-powered speaker. If I prodded the internal wiring around near the speaker posts it seemed to impact the sound, but not in a way that seemed consistently reproducible. However, the nature of the static seemed similar to when there's a live circuit with a loose connection — not unlike the humming/buzzing you get when you plug a guitar into an amp while the amp is on, for example. It did seem like the spade connector on the wire from the PCB that connects to the speaker posts internally was a bit looser than it should be, so I tried to clamp it down a bit with a pair of pliers. It seems to have helped a bit but time will tell.

If the noises comes back I might just ditch the right speaker and operate the powered speaker in a mono setup. I'm not really doing any critical listening when I'm working in the garage anyway.

 

[dekaliber]

Here's a video of the sound in case it's helpful for anyone else btw. My phone doesn't quite capture the dynamic range but it goes from soft to some pretty LOUD pops, and this is irrespective of where the volume knob is turned. https://photos.app.goo.gl/58y7Abuy1n2gFF4u8

After putting everything back together it seems like the noise is back but... quieter than before

Maybe the move here is actually getting a cheapo amp and using it to power the passive speaker. Hey, if there are two people with this problem, one of them could take the 2 passive speakers and have a functioning stereo setup!

 

[octil]

I certainly wouldn't ditch the passive right speaker, as it's less likely to fail and would be easy to fix if it does (the noise your video shows is coming from the right channel amplifier that's housed inside the left speaker). While your powered left speaker isn't having noise issues in the left channel, it could certainly start to in time.

The noise in your video sounds just like the noise I was having, although I never got the loud pops.