ThomBoh Posted February 21 Author Share Posted February 21 3 hours ago, Flevoman said: I had already mentioned it to you, but I'll mention it here as well. Both my Decware Zen triode from 2014 and my Decware Taboo III were completely silent on my AL5. These two amplifiers belong to the group of the quietest tube amplifiers I've ever had. 3 hours ago, Shakeydeal said: I had a Decware Torii II on a pair of klipschorns a few years ago. While it was not as quiet as my Aric amps, it was nothing like you describe. I think you have a system issue and not an amp issue. Thanks, both, for your sharing your experiences! So, from talking to Steve, I've learned that all of his amp designs are different in terms of their design targets and how much "inherent" hum they will have on super high efficiency speakers. He said, for example, that his 300B amp will have louder hum than his current SE84UFO25 amp, which will have more hum than his SE34I.5 amp, and so on. I don't know where the taboo sits on that scale. But I will say that I have an SE34I.5 as well in another system, and I tried it out with the La Scalas -- it was very quiet. This, however, doesn't mean that there's necessarily anything wrong with my SEWE300B or SE84UFO25s -- they are both designed to have higher level than hum than the SE34I.5... the question I'm trying to figure out here is just how much. Flevoman, your data point with the triode amp from 2014 is compelling, as that amp probably shares a lot more with my SE84UFO25 than the taboo. But still, might be too different to say. I might ask Steve about that! As for it being a "system" issue, if you're referring to other components being the problem, I think I have ruled that out. The hum I get from the amps is identical regardless of whether or not any input device is hooked up to the amps. It is independent of whether or not anything else in the room is plugged in at all besides the amp. Am I missing something? 3 hours ago, jjptkd said: This is the first I've read about this I almost put myself on that list a few years back when the wait time was 8 months I believe? I cannot image the upset I'd have felt had I waited all that time to receive a hum master. Two year wait time is unacceptable in my book- an 8 month wait was for me back then but to each their own I guess. I waited about 2 years for my amp. Wait list now seems to be at least 4 :') 20 minutes ago, Marvel said: Here is the document from Peavey about a balanced electrical system. It's basically a 120 volt transformer with a center tap that the connects to the downstream ground. each of the hot wires are then 60 volts. This is worth reading. PWRDIST.pdf 89.6 kB · 1 download Are you in your own home or a in a building that has a 208 volt three phase system for the building? If so, the way the 120 line is derived could be the problem. This is a compelling read, thank you! I live in a single detached home, and I do not own it so I don't think I can really change the electrical system that's in place. But if I were able to point out that something is wrong with it, I could get it fixed. Overall, again, I haven't come across anyone who has had the trouble with these specific amps that I am having, but I also haven't come across anyone who has paired these specific amps with these specific speakers, so, at this stage, the best I can do is to try and find someone who has. Because at this point, the manufacturer is pointing at my electrician, my electrician is pointing at my amp, and I have ruled out almost every common suggestion.. but do keep them coming! Quote Link to comment Share on other sites More sharing options...
Shakeydeal Posted February 21 Share Posted February 21 The problem is that if you have any level of inherent noise in your system, most tube amps will bring it to the surface with horns. Especially if you have excessive gain in your preamp. I used to think some level of noise in tube amps (especially in SET amps) was normal, especially with high efficiency speakers. After owning three Aric Audio amps, I have a different opinion. All of them are as dead quiet as 3 am. I mean "put your ear next to the speaker and think the amp is off" quiet. If Aric Kimball can make excellent sounding amplifiers with such a low noise floor, why can't others? Quote Link to comment Share on other sites More sharing options...
JMeader Posted February 21 Share Posted February 21 I have La Scala's with all new Crites drivers and the A4500 cross overs ( 105 db ). I waited 18 months for my Torii Jr V2 and yes I have a slight hum. I called Steve and and he suggested some different Tubes, which I got and it made no difference as to the hum issue. My hum is slightly noticeable but not annoying for me, so will keep my amp. Our music systems are for enjoyment, and I would agree that there are many great amps that do not seem to have the hum issue, so you have options to get back to enjoyment. The good news is Your Decware amps have a great resale due to waiting lists. Enjoy Your Music 1 Quote Link to comment Share on other sites More sharing options...
ThomBoh Posted February 21 Author Share Posted February 21 6 minutes ago, Shakeydeal said: The problem is that if you have any level of inherent noise in your system, most tube amps will bring it to the surface with horns. Especially if you have excessive gain in your preamp. I used to think some level of noise in tube amps (especially in SET amps) was normal, especially with high efficiency speakers. After owning three Aric Audio amps, I have a different opinion. All of them are as dead quiet as 3 am. I mean "put your ear next to the speaker and think the amp is off" quiet. If Aric Kimball can make excellent sounding amplifiers with such a low noise floor, why can't others? Broadly speaking I agree. But there's no pre-amp here (the 300B amp is an integrated), and the hum is identical regardless of whether or not a source is connected. Steve definitely could have eliminated the hum from his amps, but he chose not to for what he thinks are good reasons. 1 minute ago, JMeader said: I have La Scala's with all new Crites drivers and the A4500 cross overs ( 105 db ). I waited 18 months for my Torii Jr V2 and yes I have a slight hum. I called Steve and and he suggested some different Tubes, which I got and it made no difference as to the hum issue. My hum is slightly noticeable but not annoying for me, so will keep my amp. Our music systems are for enjoyment, and I would agree that there are many great amps that do not seem to have the hum issue, so you have options to get back to enjoyment. The good news is Your Decware amps have a great resale due to waiting lists. Enjoy Your Music Yes, I will certainly sell it if I can't figure out a solution that gets me to a bearable amount of hum. But every single account I've seen so far of using one of these amps has been overwhelmingly positive, so it's worth it to try and make it work. Quote Link to comment Share on other sites More sharing options...
Shakeydeal Posted February 21 Share Posted February 21 Maybe I missed it, but you have tried other amps in your system that do not hum? At all? Quote Link to comment Share on other sites More sharing options...
ThomBoh Posted February 21 Author Share Posted February 21 1 minute ago, Shakeydeal said: Maybe I missed it, but you have tried other amps in your system that do not hum? At all? Yes! I dont think I mentioned it. I have a Primaluna EVO 400 integrated and Naim uniti atom. No hum. It's only the Decware amps that are humming. Quote Link to comment Share on other sites More sharing options...
ned Posted February 21 Share Posted February 21 I'm running a UFO through KHorns without any issue or noise at all. Here is the stupidly obvious question - have you ruled out the preamp? If so, I think I would approach this in two ways - 1) unplug or turn off everything you can in the house and/or 2) use an extension cord to put your amp and pre amp on different circuits. I agree with everyone who mentions dimmers, LEDs, neons, fluorescents or anything that is using a transformer. Good luck. You should be enjoying amazing sound. Quote Link to comment Share on other sites More sharing options...
ThomBoh Posted February 21 Author Share Posted February 21 (edited) 6 minutes ago, ned said: I'm running a UFO through KHorns without any issue or noise at all. Here is the stupidly obvious question - have you ruled out the preamp? If so, I think I would approach this in two ways - 1) unplug or turn off everything you can in the house and/or 2) use an extension cord to put your amp and pre amp on different circuits. I agree with everyone who mentions dimmers, LEDs, neons, fluorescents or anything that is using a transformer. Good luck. You should be enjoying amazing sound. Thanks for the suggestion. Again, there's no pre-amp here, and the hum is the same regardless of whether or not there is or isn't an input plugged into the amps, and regardless of whether or not there is literally anything else in that part of the house plugged into any outlet at all aside from just the amp. Also the hum is independent of the gain/volume setting on the amps, just as loud at 0 volume as it is at max. Could try unplugging literally everything in the house. May I ask which UFO model you have? Would be a helpful data point (edit: ah, I see it's the UFO2!) Edited February 21 by ThomBoh Quote Link to comment Share on other sites More sharing options...
JMeader Posted February 21 Share Posted February 21 BTW I use a Schitt Freya S ( non tube ) preamp. I took the preamp out of the system and it made no difference so put it back in. I even tried turning the amp up and having the preamp at a lower level, and the reverse with no difference. Currently I have my amp at slightly less than half way and use the preamp for volume control which seldom get above half way. Quote Link to comment Share on other sites More sharing options...
ned Posted February 21 Share Posted February 21 (edited) I have the 2, with the decorative meters. It is dead quiet...until its not! Sorry you are having this experience. You clearly have done and bought everything for great sound. I have the volume knob on the amp at ~75% for whatever that's worth Edited February 21 by ned added content Quote Link to comment Share on other sites More sharing options...
Khornukopia Posted February 21 Share Posted February 21 37 minutes ago, Shakeydeal said: Maybe I missed it, but you have tried other amps in your system that do not hum? At all? 35 minutes ago, ThomBoh said: Yes! I dont think I mentioned it. I have a Primaluna EVO 400 integrated and Naim uniti atom. No hum. It's only the Decware amps that are humming. Have you swapped back to one of those other amps since this problem started, plugged into the same wall outlet? Quote Link to comment Share on other sites More sharing options...
ThomBoh Posted February 21 Author Share Posted February 21 (edited) 1 minute ago, Khornukopia said: Have you swapped back to one of those other amps since this problem started, plugged into the same wall outlet? Good question, and yes have also tried multiple different outlets in the room Edited February 21 by ThomBoh Quote Link to comment Share on other sites More sharing options...
Khornukopia Posted February 21 Share Posted February 21 4 minutes ago, ThomBoh said: Good question, and yes have also tried multiple different outlets in the room Everything you have stated seems to indicate an amplifier problem, but 3 different units with the same hum makes me continue to wonder about the house wiring or the power from the street transformer. It is only fair to Decware that you become certain that your house is not the problem. While we all think about the possibilities, can you post some picture of your amps? (This forum has picture file size limits, so it is best to downsize the pic file.) Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted February 21 Share Posted February 21 Hum, or hum eliminator. I have used one of these before with success. It's around $30 on Amazon and may be worth a try. 1 Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted February 21 Share Posted February 21 16 hours ago, ThomBoh said: I have tried three different Decware tube amplifiers (two different SE84UFO25s, and the new SEWE300B) and have found that with all three of them, when paired with my La Scala AL5s, there is a loud 60 or 120 Hz (maybe both) hum. This hum is independent of gain/volume setting on the amplifiers, always the same volume. I measure this baseline hum at 59 dB in my listening chair using a handheld decibel meter (C weighted). Reading through this thread it sure seems apparent to me that it is the Decware amplifiers are the source of your Hum Issue. The question then becomes why are you experiencing it at such a high SPL level at the listening chair. This makes me ask how you experience the Hum when you walk around in the room.? Do you hear it as significantly louder and quieter as you move around and also as you measure it with your SPL Meter? I could see in an unfortunate situation where a possibility that room modes at 60Hz/120Hz could be coupling very efficiently with the loudspeaker and listening positions that would exasperate the inherent by design hum of these amplifiers. An unfortunate combination of room dimensions could lead to Room Modes that could easily add +12db to the Hum Level at some areas of the room. Just a thought anyway and I hope you find a solution to this problem… 🙂 miketn 1 Quote Link to comment Share on other sites More sharing options...
Shakeydeal Posted February 21 Share Posted February 21 What is everyone saying in Steve's forum? If this is commonplace it surely is being discussed. Quote Link to comment Share on other sites More sharing options...
ThomBoh Posted February 21 Author Share Posted February 21 1 hour ago, Khornukopia said: Everything you have stated seems to indicate an amplifier problem, but 3 different units with the same hum makes me continue to wonder about the house wiring or the power from the street transformer. It is only fair to Decware that you become certain that your house is not the problem. While we all think about the possibilities, can you post some picture of your amps? (This forum has picture file size limits, so it is best to downsize the pic file.) I agree that with everything you're saying here. And yes, I agree that with the degree to which Steve has helped me troubleshoot so far, I definitely should make sure that I'm ruling out anything that would waste his time. Will post pics when I can. 42 minutes ago, mikebse2a3 said: Reading through this thread it sure seems apparent to me that it is the Decware amplifiers are the source of your Hum Issue. The question then becomes why are you experiencing it at such a high SPL level at the listening chair. This makes me ask how you experience the Hum when you walk around in the room.? Do you hear it as significantly louder and quieter as you move around and also as you measure it with your SPL Meter? I could see in an unfortunate situation where a possibility that room modes at 60Hz/120Hz could be coupling very efficiently with the loudspeaker and listening positions that would exasperate the inherent by design hum of these amplifiers. Just a thought anyway and I hope you find a solution to this problem… 🙂 miketn Good thought! I do feel pretty confident that 60/120 aren't major room modes based on the geometry, and the hum is definitely consistent as I walk around the room. Have not SPL meter'd walking around. 11 minutes ago, Shakeydeal said: What is everyone saying in Steve's forum? If this is commonplace it surely is being discussed. Here's the thread if you want to see all the info: https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1708290398 Nobody there seems to be using speakers as efficient as La Scalas with these particular amps. Plenty of people there seem have experienced hum problems with their decware amps in different scenarios, but it seems like for the most part it was found that the problem was usually a ground loop or a bad tube or something obvious. Quote Link to comment Share on other sites More sharing options...
Flevoman Posted February 21 Share Posted February 21 Can I perhaps make a very strange suggestion? Since it has been suggested a few times now that it might be your home's power grid causing the issue, if your neighbors live right next to you (such as in an apartment or townhouse), could you use an extension cord to borrow power from them to see if the hum disappears? Quote Link to comment Share on other sites More sharing options...
Shakeydeal Posted February 21 Share Posted February 21 9 minutes ago, Flevoman said: Can I perhaps make a very strange suggestion? Since it has been suggested a few times now that it might be your home's power grid causing the issue, if your neighbors live right next to you (such as in an apartment or townhouse), could you use an extension cord to borrow power from them to see if the hum disappears? That's a good suggestion. Also, you could take it to a friend's system. Even if they don't have high sens. speakers, if the amp has a hum, it'll still be present, just much lower in volume. Quote Link to comment Share on other sites More sharing options...
Khornukopia Posted February 21 Share Posted February 21 12 minutes ago, Flevoman said: Can I perhaps make a very strange suggestion? Since it has been suggested a few times now that it might be your home's power grid causing the issue, if your neighbors live right next to you (such as in an apartment or townhouse), could you use an extension cord to borrow power from them to see if the hum disappears? 1 minute ago, Shakeydeal said: That's a good suggestion. Also, you could take it to a friend's system. Even if they don't have high sens. speakers, if the amp has a hum, it'll still be present, just much lower in volume. I agree, and yes, taking it to a house in a different neighborhood would be a more effective test. Almost any speaker should work for this purpose. Quote Link to comment Share on other sites More sharing options...
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