@jean-paul my Leema Tucana II Anniversary [3 toroids inside!], Musical Fidelity E100, Musical Fidelity A200, Denon, Naim Nait 5i, all these amps were completely silent in this house. This is why I'm so upset with Pass Labs INT-25 the most expensive amp of them all and is giving me all this grief.
Sorry but in the heat of the moment I also missed that you did some tests. Still it are the toroids.
It can happen to any brand. It may be a batch of transformers that have the issue. I have toroids of the same brand and one of them is silent and the other one has a very annoying “singing” hum that comes up and goes away. Why? I have seen toroid cores with a crack that hummed extremely and that cause was clear as glass.
It should have been detected at QC, certainly if the hum occurs everywhere.
Whatever the story, I would never accept it by making someone elses problem my problem. Yes I am that customer from hell. I repaired a lot of audio and see it as replacable stuff that rarely lives longer than a few years. Even then annoying imperfections or plain errors get on ones nerves.
It can happen to any brand. It may be a batch of transformers that have the issue. I have toroids of the same brand and one of them is silent and the other one has a very annoying “singing” hum that comes up and goes away. Why? I have seen toroid cores with a crack that hummed extremely and that cause was clear as glass.
It should have been detected at QC, certainly if the hum occurs everywhere.
Whatever the story, I would never accept it by making someone elses problem my problem. Yes I am that customer from hell. I repaired a lot of audio and see it as replacable stuff that rarely lives longer than a few years. Even then annoying imperfections or plain errors get on ones nerves.
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Hi Wayne, I feel the dealer telling me that the amp is quiet at the other end of the country to where I listen is irrelevance as my listening room is at home and not at the dealer. It would be like buying a plane that didn't allow you to fly at your local airstrip due to the plane being "sensitive" to the climate there. Although the plane manufacturer/dealer never warned you this might happen, they now want to sell you thousands of dollars of extra equipment to make your plane fly where you want it to. I guess you'd be as upset as I am with the manufacturer/dealer for not providing a warning at the point of sale. All I'm hearing from my dealer is, "it works fine for us up here in Scotland". I'd really appreciate Pass Labs stepping in and helping me with this. Thanks in advance.
Four months to the day of an endless hassle since I decided to buy an amp from Audio Emotion, Scotland.
Put in writing to the supplying company that you are rejecting the item as unsatisfactory. The longer you let this drag on and the more difficult it will be to reject it.
https://www.gov.uk/accepting-returns-and-giving-refunds
If there is an element of subjectivity as to how loud this buzzing/humming is then it may need an independent assessment to give an unbiased opinion on whether the issue is unacceptable in a product of this calibre.
You need to start the ball rolling though by formally rejecting the unit.
@Mooly It is with great sadness that I feel I've been left with no choice but to register my complaint with my credit card company. Four months of hassle is where my patience with all this has run out. Like I've replied to Wayne above: It is irrelevant if the amp works quietly at the other end of the country to where I listen. I bought a Pass Labs amp to listen to at home where I live, not at my dealer in Scotland. Pass Labs should come with a warning at the point of sale that they're "sensitive" and may drive the purchaser insane unless they spend thousands on additional equipment to make them work as expected.
Well you need to do it sooner rather than later. For something of this value I suspect an independent assessment will be called for but start the ball rolling now. Don't keep waiting and hoping.
It would give the experts inhere an idea......maybe what to do about it......depending how it sounds.
Maybe some DIY advice from PassLabs.......or others.......then the thread could be transferred to a real DIY-thread 🙂
I guess it is easy to get the top off the amp.......only a few screws at top cover.......but from there it may be a bit more difficult.......
Maybe some DIY advice from PassLabs.......or others.......then the thread could be transferred to a real DIY-thread 🙂
I guess it is easy to get the top off the amp.......only a few screws at top cover.......but from there it may be a bit more difficult.......
There are three noise mechanisms commonly in transformers
1. Buzzing - caused by loose laminations. Can happen in EI and non stabilised toroid cores
2. Growling - caused by DC on the mains or by partial core saturation - can be a combo of both as well.
3. The last one is hum caused by transformer radiated EM field in the amp
If you play a recording back of the noise you are hearing it will be easy to determine what the problem is and from there propose a fix. The three sounds associated with these mechanisms are quite different.
1 above would be a manufacturing issue. 2 could be fixed by dropping the mains voltage slightly and using a DC blocker. 3 would be a system hookup issue or possibly a manufacturing problem. But again without hearing what you are, difficult to make an assessment. So, make a recording and post it up and we can perhaps set you in the right direction.
🙂
1. Buzzing - caused by loose laminations. Can happen in EI and non stabilised toroid cores
2. Growling - caused by DC on the mains or by partial core saturation - can be a combo of both as well.
3. The last one is hum caused by transformer radiated EM field in the amp
If you play a recording back of the noise you are hearing it will be easy to determine what the problem is and from there propose a fix. The three sounds associated with these mechanisms are quite different.
1 above would be a manufacturing issue. 2 could be fixed by dropping the mains voltage slightly and using a DC blocker. 3 would be a system hookup issue or possibly a manufacturing problem. But again without hearing what you are, difficult to make an assessment. So, make a recording and post it up and we can perhaps set you in the right direction.
🙂
I wouldn't advise that as doing so could jeopardise your chances of successfully rejecting the product under consumer law.
Loose laminations rattle and buzz. DC or core saturation causes the core to ‘growl’ - very different sounds. Hum comes from the speakers!
😊
😊
Hi, I plan to collect my microphone from the Church tonight [where I film the Sermons for YouTube [Chartridge Mission Church] and make a recording of the transformer noise. Thanks.