OK, I finally have an update: the amp has visited the manufacturer (Roger of Roger’s High Fidelity). Roger said that my hum was due to 2 (of 4) bad KT150 tubes. He had no explanation for why my new matched set of KT88 tubes were producing hum (at perhaps a slightly lower volume). I’m planning to purchase 4 new KT150’s from The Tube Store unless somebody out there has a better recommendation for sourcing reliable and matched tubes.
I will post again after I receive the amp back and have the new tubes installed. Thanks for everybody’s help and interest.
|
Again - sorry for the delayed reply, am currently traveling.
I powered on the amp with just the speakers connected and the hum was still present. I will try to power on the amp with nothing connected; my best guess is that the hum will still be present.
The manufacturer previously suggested that the hum was due to tube degradation. I replaced two KT150 tubes that were looking like they’d had more wear than the other two, but the hum was the same. As stated in my original post, I replaced all 4 KT150 tubes with a matched set of 4 KT88 tubes that all had limited hours on them (under 100)……and the hum was still present (although perhaps slightly softer?)
When I spoke to the manufacturer to arrange for sending the amp back, he said the only cause he could think of was the transformer.
I will be sending the amp back to the manufacturer in early December; stay tuned for an update in mid-December (hopefully, there will not be excessive shipping delays!).
|
Disconnect the speakers (and everything else), if you still hear the hum, it's obviously the amp, and likely transformer noise.
Please check with the manufacturer if it is safe to power ON this amplifier without speakers connected!
|
Since the hum appears after the tubes warm up, and not immediately, it sounds like a tube issue to me. Is the problem in both channels, or just one?
And just to confirm, the sound is coming from the speakers, and not from the amp. Is that right?
|
Read that, didn't see any harm in sharing my own experience with this.
|
He already said that he's sending it back to the manufacturer guys.
|
Sounds like transformer hum, to me. If so, it will always be the same level, won't change with high or low volume. Disconnect the speakers (and everything else), if you still hear the hum, it's obviously the amp, and likely transformer noise.
|
Try this. Unplug everything from the wall and just plug in the amp and connect the amp to the speakers.
Disconnect all interconnect cables also.
If, with the amp the only thing connected you don't hear hum, then connect the DAC to the amp/speaker combination and see/hear if you detect hum. keep going until the hum appears.
If the hum is present with only the amp connected to the speakers and nothing else is connected and plugged in, then it is the amp.
I'm glad you are sending it in for evaluation, however, I didn't see in the previous responses if you tried to isolate all component to see what is actually causing the hum.
What you don't want is to send the amp in for evaluation and they don't find anything wrong with it, and it turn out to be another component in your system.
enjoy
|
That's a good sign. It sounds like the company plans to take care you and your amp.
|
Just spoke with Roger (of Roger's high fidelity). While he could not hear the hum in the new video that I sent, he did take my word for it and asked that I send the amp back to him for evaluation and repair. He asked that I wait until early December to ship, so it'll be a few weeks until I can report back to you.
@ puptent I will try to disconnect input and see what happens. Good suggestion.
|
tubes age and degrade. if it's 60 cycle hum I would suspect a capacitor, Transformer/ rectifier... Just curious, have you isolated the amp? Physically disconnected the inputs? good luck with your gremlin
|
Sorry for the delayed reply……I appreciate the responses. I have previously sent a video with sound to Rogers and he said he couldn’t hear it. He does stand behind his equipment, so I will give him another shot with a new video.
I really like the sound of my system and the amp really fires up the Magico’s quite nicely.
Yes - I current have the amp plugged into my power conditioner. I have tried it plugged into the wall, but the sound quality is better into the conditioner and there is no appreciable difference in the hum.
I will keep y’all apprised of what happens as Roger has always been quite responsive to my queries.
|
|
Record a video with your phone describing symptoms and send it to the manufacturer.
Rogers is supposed to be a customer focused operation.
Is deep_333 ...you know who?
Looks like the new guy to ignore.
|
deep_333
You are the reason people stop coming to forums. Arrogance and stupidity just pour out of your mouth. You strike me as the type of person that just likes to shock people with your comments to get attention, like a child. My guess is that in reality, you're an idiot.
|
|
@deep_333
That all may or may not be true, but the way you addressed him made you sound like a thug.
@roxy54 , No...read it again, you invented it all in your head...But, that sly passive aggressive forum tactic of yours wanting to call me a "thug" and get away with it....Well...the way you addressed me made you "sound like a passive aggressive li’l ho". Now, go cry a river to you know who...
|
@deep_333
That all may or may not be true, but the way you addressed him made you sound like a thug.
|
@roxy54 ,
#1 He doesn’t have the right amp for that speaker (not to mention a whack a doodle hummer for the ’small price’ of only 16k!)...could be that he went tubes after the Magico started brutalizing ears. Nevertheless, the magico needs serious space heater liquidness to find the balance for --> [not held back + not tearing ears off].
#2) PassLabs will fix anything for free for the life of the amp (best customer service and service record in the history of this biz, i.e., gotta give credit when due).
P.S i don’t even own a Pass currently (lest i came off as a Pass fan boy). But, that’s the kind of amp that tends to work for Magico guys, ime.
|
|
|
Huh? 16000 dollars for this humming junk?! (I just looked it up). Return quickly to botcher Roger and get your money back.
Thereafter, get some smooth liquidy class A solid state Pass Labs to keep that Magico well behaved.
|
Rogers brags about a lifetime guarantee. It seems like he blew you off rather quickly. I would call back as @stereo5 suggested.
|
Any hum is not a characteristic of tube amps. Definitely do not give up on tube amps. I have more than 15,000 hours on tube equipment and have had to replace one tube that misbehaved. Typically, you get at least 2 - 3,000 hours between tube changes. The benefit really outweighs the risks.
It is probably a malfunctioning transformer (@2psyop +1 ) or something else (. Definitely contact Rogue. While I am not a fan of Rogue, they should point you in the right direction.
|
It could be a bad transformer. Also it could get loose in the mount. This is about the time when you find out how "good" of a company Rogers is. I have often expressed my viewpoint that service and support is an often overlooked consideration when buying any audio product. It’s not just perceived performance or reviews. If it's a bad tube, you will find out if you swap them out. Or find a tube tester to actually test them. Best of luck...
|
I have had tube amplification for years from several different manufacturers and never had any noticeable buzz or hum, not from my listening position. Had a couple that had a very slight transformer hum but you had to have your right next to the amp. How old is your Rogers? Is your amp plugged into your conditioner?
|
I would call the company back and tell them what you told us.
|
