babadono Posted February 21 Share Posted February 21 @ThomBoh sorry if I missed it...are you shorting the inputs when trying this hum test with just the amp and speakers? There is a SCIENTIFIC way to troubleshoot these types of problems. If with only the speakers connected to the amp and the inputs to the amp shorted and there is hum there is something wrong(or inherent) in the amp. Given another amp running off the same power outlet is fine. 1 Quote Link to comment Share on other sites More sharing options...
Khornukopia Posted February 21 Share Posted February 21 4 minutes ago, babadono said: @ThomBoh sorry if I missed it...are you shorting the inputs when trying this hum test with just the amp and speakers? There is a SCIENTIFIC way to troubleshoot these types of problems. If with only the speakers connected to the amp and the inputs to the amp shorted and there is hum there is something wrong(or inherit) in the amp. Given another amp running off the same power outlet is fine. I agree with you also but, it seems strange that 3 different amps have the same problem. Quote Link to comment Share on other sites More sharing options...
babadono Posted February 21 Share Posted February 21 4 hours ago, ThomBoh said: Am I missing something? maybe Quote Link to comment Share on other sites More sharing options...
babadono Posted February 22 Share Posted February 22 did we lose the OP @ThomBoh ? Quote Link to comment Share on other sites More sharing options...
sanblomo Posted February 22 Share Posted February 22 Hi, I'm not a Klipsch owner, but I have open baffle speakers which are 100db efficient. Also, I have a pair of high sensitivity Audio Note AN-E. I waited for over two years to get my Decware amp. I switched my order to the 300B amp about eight months ago from the SE84UFO25. End of January I finally received the amp and plugged it in. To my disappointment, I heard the hum too. It pressurizes my room at 120Hz with about 50db at my listening position. We are talking amp system specific hum, not ground hum or transformer hum. I listen to classical music often, and in quiet passages the hum is intolerable. I also exchanged mails with Steve Deckert, but he couldn't offer me a remedy. I was able to sell the 300B in no time. I told the new owner all about the hum issue and said he should check the development forum on the issue. The reviewers never mentioned hum. I think that is strange, they certainly should have heard it. One of my goals for my rig has always been to reduce the noise level and increase dynamic range. Unfortunately, the Decware just didn't fit into my system. Oh well, that, I suppose, is just part of the hobby. Quote Link to comment Share on other sites More sharing options...
ThomBoh Posted February 22 Author Share Posted February 22 17 hours ago, babadono said: did we lose the OP @ThomBoh ? Had to go to work, will update this evening Quote Link to comment Share on other sites More sharing options...
babadono Posted February 22 Share Posted February 22 Dang that work thing always gets in the way Quote Link to comment Share on other sites More sharing options...
Silverfoxvtx1800 Posted February 22 Share Posted February 22 I have Forte lVs and I had a humm with Decware,Had and Primaluna..drove me crazy..the fix was to get rid of all tube amps and put the Pass Labs XA25 in…no hum and sounds better then tube amps.. Having a hum is the worst, the Primaluna had a terrible hum and noisy in general…it’s a boat anchor..got tired of my sons younger ears telling me of all the bad noises..the Pass gear no one is complaining.. Quote Link to comment Share on other sites More sharing options...
OO1 Posted February 22 Share Posted February 22 good to know Quote Link to comment Share on other sites More sharing options...
babadono Posted February 22 Share Posted February 22 I am afraid this will be the case in the OPs situation as well. Only he can decide if he can live with the hum. But he still needs to short the inputs to get to the inherent hum level. Quote Link to comment Share on other sites More sharing options...
Silverfoxvtx1800 Posted February 22 Share Posted February 22 I don’t what’s going on with my system but this PassXA25 amp and the XP-12 Pass preamp is dead quiet..it’s the best sound I have had. Bought my first Forte in 1985 and the Forte IV a year ago…haven’t had any other speakers..never will go the tube route again..the sound now gives me shivers …can’t turn it off Quote Link to comment Share on other sites More sharing options...
Shakeydeal Posted February 22 Share Posted February 22 Don’t blame the tube amps. There are other things afoot… 1 Quote Link to comment Share on other sites More sharing options...
Silverfoxvtx1800 Posted February 22 Share Posted February 22 Never tried Aric amps but there is definitely great things said about his amps.i was really close to trying his gear but after burying a shorted out Primaluna tube in the backyard I decided to go SS with the Pass Labs and very happy I did..the Primaluna EVO 400 I had was a constant problem after about 6 months of use and I use my gear more then the average bear being retired…the Decware I could hear the hum from my sitting position and being 70 that’s saying something…I took it to many friends systems and the same results…the Had amp had just a little hum that was bearable but my son could hear it so sold them and went to Primaluna…it had a slight hum but there was other noises too..after 4 hours of use it would make a noise like metal bending…weird..and you could hear weird little noises and tubes were shorting out. I am definitely happy with my Pass gear…I am sure we all have different experiences…for sure there are great tube amps out there… Quote Link to comment Share on other sites More sharing options...
geezin' Posted February 22 Share Posted February 22 The troubles I've seen others have steers me clear of tube units. Honestly I'm running my Heresy off a Topping PA3s and it's dead silent. After some sorting out it sounds great to me. I may try a higher end class D in the future but for now I'm good. Quote Link to comment Share on other sites More sharing options...
KT88 Posted February 22 Share Posted February 22 I wouldn't describe all tube amps in general as "hummers". I have had an MC275 MK4 for 23 years and it is absolutely quiet even at 108 dB UJ. Even vintage amps like my Leak stereo20 and Quad II are absolutely quiet. Ok, the Leak is a bit noisy because of the very high sensitivity, but no hum. I am absolutely no expert, what I have learned is that the double hum frequency has nothing to do with ground loop. If you hear 120Hz or in Europe 100Hz (and you can clearly hear that if it is double the mains frequency) then that is the sound after the rectifiers have turned the negative half wave to the positive side. This doubles the frequency. This is followed by the PSU filter capacitors in the circuit. If one of these caps is broken, you will hear this doubled mains frequency, same in an SS amp. I cannot contribute to the solution if an amp is new and has been tested before delivery. But it must have something to do with the mains filter or the mains filter caps, or their size? but not with ground problems. 1 Quote Link to comment Share on other sites More sharing options...
mark1101 Posted February 23 Share Posted February 23 Dumb question: Have you tried a "cheater" plug (temporarily) just to see if lifting ground does anything? Obviously, this is not safe and hopefully you are plugged into a GFI anyhow. Another dumb question: Have you tried shorting the inputs when you power up and have nothing connected on those inputs? April 10, 2024 will be two years I have been waiting on a pair of SE84UFO. I was around number 1250 when I purchased, and now I am around number 400. How stupid.......I will never do anything like that again. I hope I still have the same email and phone number when they finally build those things. I hope I have the same address. I hope I am still alive. 🙂 1 Quote Link to comment Share on other sites More sharing options...
babadono Posted February 23 Share Posted February 23 23 minutes ago, mark1101 said: I hope I am still alive Well there is that Quote Link to comment Share on other sites More sharing options...
babadono Posted February 23 Share Posted February 23 56 minutes ago, mark1101 said: Dumb question: Have you tried a "cheater" plug (temporarily) just to see if lifting ground does anything? Maybe not so dumb...just looking through Decaware documentation they suggest it and say nothing about it being temporary(?). Also specs state 120HZ down only 68dBu (?) Quote Link to comment Share on other sites More sharing options...
Marvel Posted February 23 Share Posted February 23 @babadono don't know if you read the paper romance Peavey. If u live in a standalone home it probably won't apply, but in a building that's fed by a 208 volt transformer, this bears repeating. When we hook up audio equipment in a building that has the 120 volts required, derived from a 208 volt three phase system, we are faced with more than a 60 Hz ground loop, we end up with 60, 120, and 180 Hz ground currents, that get into the audio system. The would normally be installed in the mains panel, but could be put in a separate box in the audio room if you were careful. 2 Quote Link to comment Share on other sites More sharing options...
Edgar Posted February 23 Share Posted February 23 2 hours ago, mark1101 said: Dumb question: Have you tried a "cheater" plug (temporarily) just to see if lifting ground does anything? Obviously, this is not safe and hopefully you are plugged into a GFI anyhow. Another dumb question: Have you tried shorting the inputs when you power up and have nothing connected on those inputs? Neither question is dumb; both are standard procedures in a case like this. Also check to see if the "hot" and "neutral" connections in the wall plug are reversed. One of these will do the job for you. I have a (solid state) amplifier that only hums when the ground is lifted. I have another (solid state) amplifier that always hums unless I use one of these. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.