realysm42 Posted December 17, 2020 Posted December 17, 2020 (edited) Hi, I've had intermittent trouble with my right channel 'crackling' when music is played. I've worked to isolate the source of the issue by performing the following troubleshooting steps (below) and I'm confident the issue is with the right hand monoblock amplifier: Swapped left and right speakers around Swapped left and right channel interconnects into my preamp Swapped left and right speaker cables None of these changes made the crackling sound move to the left channel. I'm reluctant to try moving the amps as they're heavy and awkward to move. **Edit** I forgot to say (and I'm sure this is important) - I've noticed now that the right channel sounds degraded all the time (not just intermittently), it's hard to articulate, but it sounds muddy and nowhere near as clear as the left channel. I'm sure it's slightly quieter as well. Plus, upon further inspection, one of the speaker cable terminals on the suspected amp is only what I can describe as 'loose' - I've no idea why / how this could be but I discovered it when swapping the speaker cables over. The terminals are the WBT locking type; when I tried to tighten it up, there was play in the part of the terminal that's meant to stay still. Bearing all the above in mind, I think the crackling is caused by a loose fitting speaker terminal in the right hand monoblock. My next question is how do I fix this? Ideally I'd have a professional come to my house, first of all to diagnose the issue (again the amps are heavy and I'm sure I've isolated the root cause, but it'd be frustrating to bring the amp to someone only to find it's working fine) and then to fix it. Can anyone here recommend someone with the skills that I could speak to please? I appreciate any help / advice offered - thanks. Edited December 17, 2020 by realysm42
muon* Posted December 17, 2020 Posted December 17, 2020 Would it help to mention what the amp/s are /is? Sounds like you might need to replace that speaker binding post, if that is the issue. 1
realysm42 Posted December 17, 2020 Author Posted December 17, 2020 Just now, muon* said: Would it help to mention what the amp/s are /is? Sounds like you might need to replace that speaker binding post, if that is the issue. Hi - the amps are LongDog Audio P6 Monoblocks. I'm hoping they're not damaged and need replacing although I guess that's what a good engineer will be able to assess. 1
muon* Posted December 17, 2020 Posted December 17, 2020 Nice amps As you say you need someone to have a look at it, and determine if it is a continuity issue on that post, or something else. Not being a Melbournite I haven't any recommendations but I'm sure someone will be along shortly with some useful information. 1
realysm42 Posted December 17, 2020 Author Posted December 17, 2020 2 minutes ago, muon* said: Nice amps As you say you need someone to have a look at it, and determine if it is a continuity issue on that post, or something else. Not being a Melbournite I haven't any recommendations but I'm sure someone will be along shortly with some useful information. Thank you - I'm smitten with them! It's a shame one is not fully working now as I was planning to get some serious music sessions underway over the Christmas break. 1
stereo coffee Posted December 17, 2020 Posted December 17, 2020 The speaker terminals as I read are WBT, one of the premier brands http://www.wbtusa.com/pages/binding_posts.html As you say the internal fitting is loose, which of the 4 they make is fitted to yours ? Most of WBT products have data sheets so you can see exactly how they are made The construction looks to be plastic moulded over metal, but may have a locking collar which may just need tightening. Let us know which model. If doing this work yourself have the amplifier off with power cord disconnected.
pete_mac Posted December 17, 2020 Posted December 17, 2020 (edited) 10 hours ago, realysm42 said: Hi, I've had intermittent trouble with my right channel 'crackling' when music is played. I've worked to isolate the source of the issue by performing the following troubleshooting steps (below) and I'm confident the issue is with the right hand monoblock amplifier: Swapped left and right speakers around Swapped left and right channel interconnects into my preamp Swapped left and right speaker cables None of these changes made the crackling sound move to the left channel. I'm reluctant to try moving the amps as they're heavy and awkward to move. **Edit** I forgot to say (and I'm sure this is important) - I've noticed now that the right channel sounds degraded all the time (not just intermittently), it's hard to articulate, but it sounds muddy and nowhere near as clear as the left channel. I'm sure it's slightly quieter as well. Plus, upon further inspection, one of the speaker cable terminals on the suspected amp is only what I can describe as 'loose' - I've no idea why / how this could be but I discovered it when swapping the speaker cables over. The terminals are the WBT locking type; when I tried to tighten it up, there was play in the part of the terminal that's meant to stay still. Bearing all the above in mind, I think the crackling is caused by a loose fitting speaker terminal in the right hand monoblock. My next question is how do I fix this? Ideally I'd have a professional come to my house, first of all to diagnose the issue (again the amps are heavy and I'm sure I've isolated the root cause, but it'd be frustrating to bring the amp to someone only to find it's working fine) and then to fix it. Can anyone here recommend someone with the skills that I could speak to please? I appreciate any help / advice offered - thanks. I think it’s unlikely that the issue is due to the loose binding post. According to pics, this amp has the WBT Next-gen binding posts and the speaker wiring uses push-on spade-style connectors. This means there is some inherent flexibility in the wiring which connects to the rear of the binding posts. It’s not the kind of connection and wiring which is stiff and would suffer from intermittent connections due to movement of the binding post. That said, I could be entirely wrong! edit: I probably should have said that it does make sense to rectify the loose binding post in any case, to either confirm or rule it out as the source of the issue. Edited December 17, 2020 by pete_mac 2
realysm42 Posted December 17, 2020 Author Posted December 17, 2020 Thanks all for your input; it's spurred me on to decide I'll take a closer look today. You can probably tell by how I've spoken about the issue I have very little technical knowledge - so fingers crossed me having a play fixes it. I'll report back later today! 1
Cloth Ears Posted December 17, 2020 Posted December 17, 2020 Have you considered it could be your source? I had an issue similar in two places. One was the car, and it turns out the power supply of my source (160GB Ipod using digital out). And the other was the electronic analog crossover (also a power supply issue - degraded caps).
muon* Posted December 18, 2020 Posted December 18, 2020 I wouldn't have thought the post just became loose, but stranger things have happened. Hope You find It's as simple as that
realysm42 Posted December 18, 2020 Author Posted December 18, 2020 1 hour ago, Cloth Ears said: Have you considered it could be your source? I had an issue similar in two places. One was the car, and it turns out the power supply of my source (160GB Ipod using digital out). And the other was the electronic analog crossover (also a power supply issue - degraded caps). Thanks for your suggestion and I did consider this - my reasoning that this isn't the problem is: 1. if I had a problem in the right channel of my source, 2. it would be highlighted by swapping the inputs to my preamp (as the right channel would 'become' the left and thus the problem should shift over) and it didn't. 1
realysm42 Posted December 18, 2020 Author Posted December 18, 2020 51 minutes ago, muon* said: I wouldn't have thought the post just became loose, but stranger things have happened. Hope You find It's as simple as that Maybe it was always loose and I just didn't realise, who knows? I know it's tenuous, maybe I'm just kidding myself but I hope I'm right as this is something I may be able to fix without paid for help. 1
realysm42 Posted December 18, 2020 Author Posted December 18, 2020 I tightened up the offending loose terminal and the issue persists. As a bonus I nearly dropped the amp off of its isolation platform putting it back into the rack; I was ~0.5cm away from disaster and it was sheer good luck nothing happened... The next thing I'll do is take out all the cables in my system and clean them and their corresponding terminals; I was shocked at just how discoloured the RCA input on the amp was! I honestly don't think this will fix the issue but it needs to be done anyway. It sounds permanently quieter and more muffled with intermittent crackly distortion on the right channel. God I love this hobby; sometimes it feels more like a job
muon* Posted December 18, 2020 Posted December 18, 2020 Off to the Doc's it seems. I had a valve amp fall from a table once, but I broke It's fall with my forearm and nearly broke that Glad you avoided that near mishap 1
Auracle Posted December 20, 2020 Posted December 20, 2020 Wherabouts in Melbourne are you? Considering what you have tried already, the diminished and muffled sound with crackling sounds very much to me like either a cap or solder joint problem. 1
miyouzaic Posted December 20, 2020 Posted December 20, 2020 On 18/12/2020 at 12:06 PM, realysm42 said: Thanks for your suggestion and I did consider this - my reasoning that this isn't the problem is: 1. if I had a problem in the right channel of my source, 2. it would be highlighted by swapping the inputs to my preamp (as the right channel would 'become' the left and thus the problem should shift over) and it didn't. It seems you have overlooked the middle link in your audio chain.. as you have only mentioned swapping "inputs" to your pre-amp and no method of eliminating your pre-amp and or the interconnects between the pre-amp and the power amplifiers. Indeed, swapping the input into the pre-amp L-R ,..is swapping the audio signal and enabled you to eliminate your source... but from the input of your pre-amp, to the input of your power amp.. nothing other than "correct" L and R channel signal was changed ! To eliminate further possibilities.. Swap the interconnect cable, complete, between your pre-amp and power-amp, left to right and right to left. If the problem remains to the right amp and speaker... Next is to narrow down if it is your pre-amp.... by swapping the ends of the interconnects at your "pre-amp OUTPUT" RCA's from left to right and right to left. If pain persists..... 2
bob_m_54 Posted December 20, 2020 Posted December 20, 2020 10 hours ago, miyouzaic said: It seems you have overlooked the middle link in your audio chain.. as you have only mentioned swapping "inputs" to your pre-amp and no method of eliminating your pre-amp and or the interconnects between the pre-amp and the power amplifiers. Indeed, swapping the input into the pre-amp L-R ,..is swapping the audio signal and enabled you to eliminate your source... but from the input of your pre-amp, to the input of your power amp.. nothing other than "correct" L and R channel signal was changed ! To eliminate further possibilities.. Swap the interconnect cable, complete, between your pre-amp and power-amp, left to right and right to left. If the problem remains to the right amp and speaker... Next is to narrow down if it is your pre-amp.... by swapping the ends of the interconnects at your "pre-amp OUTPUT" RCA's from left to right and right to left. If pain persists..... The first place to check when using the "half-split" method too.
realysm42 Posted December 20, 2020 Author Posted December 20, 2020 21 hours ago, Auracle said: Wherabouts in Melbourne are you? Considering what you have tried already, the diminished and muffled sound with crackling sounds very much to me like either a cap or solder joint problem. Hey mate, I'm in Sunshine (west of Melbourne). Your suggestions are fair ones. I've read the other pointers below and I'll make sure to test these out first as I need to be 100% sure where the fault lies.
realysm42 Posted December 20, 2020 Author Posted December 20, 2020 @miyouzaic fair points, thank you. I'll have a crack with that now.
realysm42 Posted January 11, 2021 Author Posted January 11, 2021 On 20/12/2020 at 8:43 PM, miyouzaic said: It seems you have overlooked the middle link in your audio chain.. as you have only mentioned swapping "inputs" to your pre-amp and no method of eliminating your pre-amp and or the interconnects between the pre-amp and the power amplifiers. Indeed, swapping the input into the pre-amp L-R ,..is swapping the audio signal and enabled you to eliminate your source... but from the input of your pre-amp, to the input of your power amp.. nothing other than "correct" L and R channel signal was changed ! To eliminate further possibilities.. Swap the interconnect cable, complete, between your pre-amp and power-amp, left to right and right to left. If the problem remains to the right amp and speaker... Next is to narrow down if it is your pre-amp.... by swapping the ends of the interconnects at your "pre-amp OUTPUT" RCA's from left to right and right to left. If pain persists..... I took your advice and attempted this (admittedly with a dose of scepticism) and... it fixed my issue! It must have just been a weak connection; I simply swapped left to right and bam! Problem solved! Thanks for your advice sir, you saved me a costly mistake. 2
andyr Posted January 11, 2021 Posted January 11, 2021 5 minutes ago, realysm42 said: I took your advice and attempted this (admittedly with a dose of scepticism) and... it fixed my issue! It must have just been a weak connection; I simply swapped left to right and bam! Problem solved! Thanks for your advice sir, you saved me a costly mistake. Nice to hear you have fixed the problem. Correct diagnosis of audio problems can be very tricky! Andy 1
realysm42 Posted January 11, 2021 Author Posted January 11, 2021 (edited) 30 minutes ago, andyr said: Nice to hear you have fixed the problem. Correct diagnosis of audio problems can be very tricky! Andy Indeed; what's supremely frustrating to me is how long I put up with a problem I was so close to solving myself... Still, it's a useful learning experience to thoroughly troubleshoot and not be blinded by my own assumptions. And it's a far cheaper outcome than the alternative options. As a sidenote; Nick Gorham (Longdog audio) offered to get this monster of a monoblock shipped back to the UK, at his own cost, to have a look for me - superb service! Thanks also to @Auracle for your offer of help too. Edited January 11, 2021 by realysm42
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