A couple of questions I can start you with might help folks zero in on the problem.
First: what is the brand name and model # of the speakers you are using, and what is their sensitivity rating?
Second: is the sound you hear out of the speakers (without program material) influenced by the volume setting of the DK?
Third: is the sound a "hissing/static" sound (like AM radio static), or a "buzzing/humming" sound?
Fourth: clarify for us again whether the sound is coming from the unit itself (chassis noise) or directly from the speakers - for example, when there is nothing playing, but the equipment is turned on, describe what you hear with your ear 3 inches, 1 foot and 2 feet away from the speaker.
Regards,
Mike |
Hi Mike, here are the responses to your questions...hope my answers are clearly enough to pinpoint to where the problem may be. Your questions are very helpful...
1. I am using Hyperion Sound 938s, and sensitivity is at 90dB
2. Yes, the noise I am hearing is coming from the speakers (without program material) influenced by volume setting of DK
3. The sound is more like hissing/static sound like AM radio static..you are correct.
4. The static sound is coming from the speakers, not from the DK unit itself. The chassis is silent so far. with the equipment turned on and nothing playing, at about 3in., I hear pretty audible hissing/white noise from both speakers. At about a foot away, you can still here the white noise, at about 3ft away, you can not hear the white noise. Now, if you turn the volume control up without music playing, there is that additional nasty static noise mentioned above coming from the speakers and you can here this noise even 8-10ft away..(from listening position)..The static noise is heard usually when the volume nob passes about 11'oclock to 13'0clock mark...extremely strange, yeh ? two DK units both displaying exactly same problem...
thanks Mike. |
Tubes hiss. Fact of life. Not a problem. But with the volume set up that high wouldn't any music playing completely mask the hiss? |
I have to agree with Eldartford. When I turn my DK's volume up to to 11 o clock, I can clearly hear tube rush through my Gallo Ref 3's without program material playing. As your speakers are more sensitive, I think this would be exacerbated. You must be listening in an extremely large room to be using the DK with the volume set at 11 o clock and above? I can't use mine much above 9 o clock. |
I concur with the previous posters. Tubes do hiss with or without program material, and the more sensitive the speakers, the more you'll hear it. Normally, you'd not hear the hissing more than a foot or two away from the speakers. If you're hearing more than that, the tubes you have might just be noisy. Tubes vary individually in the amount of noise they will produce, even between samples of the same brand/type/year etc.
I would call a reputable tube dealer like Upscale Audio or "The Tube Store" and ask them if they have any low-noise 6922s you could buy - describe what you're hearing and see what they recommend. You'll pay more for tested, trusted tubes, but you should get very high quality and reliable product. Even brand-new production tubes these days aren't always noise-free - noisy ones are common in my experience.
Good luck! |
You wouldn't by any chance be connected to cable FM? That is notorious for ground loop hum. 90 db speakers are pretty sensitive, so, I agree, going for phono stage quality 6922's would be worth a try. I like Andy at Vintage Tube Services, for his opinions and expertise in providing well tested nos tubes, probably worth the modest added expense given the quality of your equipment. |
All, thanks for your responses, first of all.
I hear you about the tubes and possible hissing/white noises they make. I have owned tube gears before and know the hassle, especially with 6922s. However this is not a normal hissing noise. I am talking about a very loud static noise as if you were tuned to a very bad radio frequency. I don't think that is normal tube noise. Especially doesn't explain why such noise comes and goes around specific range of volume, don't you think ? Same static noise around same range of volume, no matter which tubes I put into DK..this lead me to suspect that it is more DK than tube matter given the patterned noise reaction I am seeing.
Anyone who own the DKs here that can test and see if similar reaction is happening ? with music feed off, and only DK on, turn the volume lever up past 11-12'oclock range and see if you hear audible static noise..if you got high sensitivity speakers, the noise will be louder for sure. |
I don't think the tube hiss is what pkoh70 is concerned about. He acknowledges that hiss but says he can't hear it at 3 feet away. As I read his posts, the complaint is aboout a separate noice -- a buzz -- that kicks in at the 11 o'clock position but stops at 1:00 o'clock and is audible from any distance. |
You've mentioned that this sound appears when there is no music on. I assume that you mean playing. Try disconnecting all of the inputs to the DK - this will eliminate the possibility that the problem is originating in a source. FWIW. |
Drubin, you got it ! That is exactly what I am talking about. I am ok with the tube noise. What I am absolutely not ok with is that loud, static noise made when volume knob passes specific range..(mostly 11-1'oclock range)And this symptom has occured on two DK units. (original, and replaced)..The noise is clearly audible at a listen position by the way. (10-11ft. away)
and once again, thanks to all those offering inputs/insights here. |
Might this be a bad volume control (potentiometer)? That can produce a scraping sound, and depending on where the bad spots are in the pot, it can be quite loud. It would be a coincidence to have two of these with the same problem, but anything is possible. |
I had a similar issue with the volume control on my tube preamp, a Joule Electra. From about 11 o'clock to 1 o'clock each move up in volume resulted in a static noise being emmitted from the speaker. My preamp had two volume pots and only the right channel had this effect. I generally was able to remedy the problem by turning the knob frequently back and forth several times. However, this was only a temporary fix. It was recommended by Joule to replace that pot. |
Did you try calling them?I assume you already sent them an email.Best of luck. |
Bob,
yes, have exchanged e-mails with LSA group and it's local importer here and am waiting for their finding. They have been very responsive "so far", including Larry Staple who is the president of the company. |
Let us know how you make out as Larry seems to be very good at taking care of issues from what i have read.
Regards,Bob |
hi there, i have the same issue. my hiss came from my phono input when i had something plugged in to the balanced inputs. try this: if you are using balanced inputs, take the cables out. does the hiss go away? mine did. |
Hi Rbstehno,
based on the recommendation by DK and by reviewers, I am using singled ended and do not use balance connection at all. If you are having hiss issue when using balanced, that seems like it could be another issue that you should look into. |
I have the MK 111 version, so tried the volume control with no input, No noise to maximum volume. I like this amp very much, using Amperex 7308's, I am getting some A frame orange to try next.
Bob |
Sounds like one of the tubes has worked it's way up.
My DK has done the same thing! Just clean the tubes pins
and re-seat it. Poor contact has caused your problem.
I keep a back up set of tubes around. That cage thing
also makes it hard to get to them. I have a set of
Amperex PQ's which I almost gave away before I found
the problem. They are working well in my DAC! |
