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extracampine

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Everything posted by extracampine

  1. Thanks for your reply Chris, and yes I am sure that my interpretation was not the meaning you had intended. It was just the flavour I got from the name and quite possibly what some other perhaps more outside observers might glean from it also. I can see however how the original name ComputerAudiophile was starting to sound a little dated, as these days with the emergence of all manner of network audio devices the computer no longer holds the pivotal role that it once did, say in the era of the CAPS v1 developments! Perhaps the word "digital" might be more apt than "computer" these days.....DigitalAudiophile....hmmm....certainly doesn't rhyme very well....
  2. The problem here is the use of the term "style". This term serves to make our hobby sound superficial, image-oriented and somewhat ostentatious. The obvious connotation is to fashion - image-obsessed and transient. The use of this term here would seem to undermine the purpose of this site - taking the focus away from an approach based in science, electronics or computers and reinforcing the image of audiophiles being concerned with "style over substance".
  3. It's still running fine now. Only change is I have switched to a different DAC so added an SoTM tx-usbexp card.
  4. I've not frequented this site as much recently and am therefore a little out of the loop - but why was the name changed from Computeraudiophile to Audiophilestyle? I think I prefer the former as it is a clearer description of the site.
  5. Still trying to work out if this is tongue in cheek or not....?
  6. Yes, you really needed a fairly silent environment to pick up the hum (with no ambient noise in the background). I had worried about there being too much noise at the Lampizator testing lab and had mentioned this to them in my first email. But that is how I (and likely others) like the listening room - silent! From some of the comments, I'm surprised that this isn't a more recognised issue. It's not that I have super-sensitive hearing or that my room is an anechoic chamber or anything!
  7. A final update for anyone that is interested or experiencing a similar problem. I ended up returning the DAC to the manufacturer (Lampizator) a second time. This time they replaced the transformer with the one they are using in their newer DACs. I had thought that the noise was coming from the choke (what I had initially thought was a EI transformer), so was somewhat skeptical that replacing the toroidal transformer would make a difference. So on unpacking, inserting the tubes and making the various connections at the rear, with trepidation I pressed the power switch. And....BOOM the DAC blew up!! Just kidding...THERE WAS NO HUM!!! Hallelujah! Or, more accurately, there was a very low level of hum which is in keeping with the other audio components and not audible once a foot or two away from the DAC. So after a (fairly) long road, this problem has been solved. Thanks to all for the advice given
  8. OK, I had it checked by a local electrical engineer - he seemed to think that the level of transformer hum was within manufacturers tolerances.
  9. Conducted a further experiment. I plugged the DAC in in a music shop some 35 minutes drive away to see if it would still hum whilst on a different part of the grid - and it did. So it would seem to be less likely that it is something else in my house, or the power supply to my house, which is causing the problem.
  10. Interesting! Did you try plugging the amp in somewhere else, other than at your house? I tried it at my work too and the hum remained the same - thus reducing the possibility of something like what you had experienced, I think.
  11. I tried measuring the mains DC with the meter set to a range of 600V DC, but it didn't measure anything.
  12. I have the Sinometer 830B - this one: http://jbryant.eu/pages/DMM.htm I think it has a DC range of 600V, to the left of "OFF" if I am not mistaken?
  13. OK One and a half - I looked back at the post you mentioned. Here are my findings: Black probe to earth, red probe to active: 246V Black probe to earth, red probe to neutral: nothing registered on my multimeter - 0.00V (however the lowest "setting" for AC V is 200V) Black probe to neutral, red probe to active: 246-247V You initially said that it should read 230V. Does this therefore seem quite high?
  14. Yes, I gathered that this was normal and within the acceptable range as far as the transformers are concerned. One and a half - what other measurements would be helpful here?
  15. OK, further to the above - I tested the mains voltage at an outlet in my house with a multimeter and it was reading both 245 and 246 volts.
  16. Thanks for this reply Bob. I don't think I can feel a vibration when touching the case. Although I say that I can hear the hum/buzz from a distance, it is still relatively quiet. Regarding the over-voltage, I am going to use a multimeter to check the mains voltage in the house in the next day or two. You are correct re the tubes - 1 rectifier tube and 4 DHP tubes. I will make sure it is off in future when poking around inside I doubt that it could have been static - the shock was a little too pronounced, and it happened twice. Item B (the transformer/choke) is bolted to the base of the case via 2 of the 4 available bolt points. I will look further into this with a plastic rod as you suggest. Yes, the fact that my Classe amp hums (though to a lesser extent) and my linear PSU (now to a lesser extent also - I think it used to be worse) makes me wonder about my mains. I still plan to measure this as mentioned above, and try the DAC a bit further afield.
  17. Thanks for the ongoing insights here - though some of the technical discussion is a little above my head I have 4 further small findings that might help in the quest to remove the hum; 1. I took the case off (again) to see if the rod that holds the transformer needs tightening or loosening. What I found before getting to that however, was that the casing seems to be contributing to the noise. With the case removed, the noise is definitely less. It is still audible, though perhaps heading towards the level that would not be noticeable from the listening spot. I had tried removing the case before and don't remember a particular reduction in noise, but there you go. So I got some thin rubber pads and tried to insert them in-between the front panel and side casing. Once the screws were again tightened, this did not seem to improve the noise. Flexing or moving the top casing also seems to affect the noise somewhat, though inserting anything in-between this and the base is quite tricky. Either way I did not have the impression that inserting further bits of rubber would likely affect the noise, given my findings with the rubber at the front. 2. Trying again to isolate the area that the hum is coming from, I think it is coming from a different component to what I had expected. I had thought that the noise was coming from the main transformer (a big round thing which I have labelled 'A'), though it appears to be coming from somewhere nearby. The exact culprit is difficult to determine, though I'm wondering if it is coming from the component highlighted in my photo below (which I have labelled 'B'). I'm not sure what this component is but am wondering if it is also a kind of transformer? 3. I noticed that one of the bolts/pillars holding the PCB to the casing appears to have current running through it (if that is the right term) - when I touched it, I felt a small shock. I can't remember if my other hand was touching the casing or not. I also don't know if this is normal/expected or not. The unit was powered on at the time. Maybe I was stupid to be prodding around inside with the power on. I don't know if the other 4 bolts are the same (I didn't fancy testing)! I have highlighted this bolt in the picture below also. 4. I took the DAC to my workplace and plugged it in there. Same hum. It is however only about 3 miles away as the crow flies - don't know if this is relevant or not. Thanks again for the help here.
  18. Don - thanks for the specific suggestion Yes I will look into that. Won't such a transformer dampen dynamics and limit peak draw? Peter - you're saying that measuring DC offset on the mains using a multimeter is not a viable option? Perhaps a more powerful oscilloscope is required for such measurements? I did not try the power amp or HDPLEX on their own, no - I'm mainly concerned about the DAC as that has the most prominent hum. And no, I have not yet tried the DAC elsewhere - what I did do was send it back to the manufacturers (in Poland) where there was no hum found. What I will do in the next few days is try the DAC elsewhere in the UK, first at my work and if it still hums there (it is only 5 minutes drive away) then I will try it further away (e.g. a music shop 30 minutes drive away). If it does turn out to be silent at work I will be pleased as it will be a clue as to the problem!
  19. Could you post a link to the kind of transformer you mean?
  20. Well, I just opened the circuit breakers for all circuits in the house except the one the DAC is on, and turned off all items except for the DAC (including the NAS, good point Peter). And no change to the hum. So perhaps that rules out something else in the house generating noise on the line. I do own a multimeter - or if I didn't, they're cheap enough to buy. I am going to test the mains with it to see what the AC voltage is doing; hopefully report back with this in the next few days. As far as I know there is only one earth here Peter. I am also going to take the DAC to my work to see if it hums there. And if it does, I will take it maybe to an audio store that is a bit further away to see if it hums there.
  21. Ray - sorry, I had somehow missed your earlier post. I was considering a P5 at one point. I have heard however that the P5 itself has transformers and is liable to hum. Also, it is a rather expensive solution to solve a problem of hum which shouldn't be there in the first place! I would be keen to try a P5 or equivalent though, just to see if that fixed the problem.
  22. zoltan - I have seen the PS Audio Humbuster mentioned. I beleive that it is out of production and hard to find. If it worked, then surely there should be an equivalent product elsewhere? As I mentioned, I have already tried 2 DC blockers, neither of which seemed to affect the hum very much. One and a half/mansr - I will test the mains voltage and report back Peter - interesting that you still reckon that it is DC offset, despite my 2 DC blockers not working. Do you think they were ineffective? The MCRU one was not cheap - around £350 or so I think. I do not have any PCs that run off SMPSs. The audio PC has a linear PSU from HDPLEX (which I have switched off, but this made no difference). Regarding switching things off around the house - I can open the circuit breaker for all circuits in the house except the ring circuit that the hifi is on, and disconnect everything from that circuit apart from the DAC, to make sure that it is only the DAC that is drawing power in the house - is that what you mean? If I get it quiet with this procedure I would be overjoyed! What do you mean by USB isolator? Don't think I have one of those. My music is in another room on a NAS which connects to the audio PC in the listening room via ethernet; that then connects to the DAC via USB. The only thing is, I could switch everything off in the house, but couln't it be a neighbours appliance that is affecting our mains? Can't really ask them to switch all their appliances off every time I want to listen to music
  23. STC - interesting that your Classe amp had hum when voltage was more than 248V for a 230V rated device. When being tested at the manufacturer, they used up to 250V and still no hum was heard. rayooo - yes a few others have mentioned that DC on the AC line may be a potential cause. As mentioned above, I tried 2 different DC blockers (from MCRU and ATL Hifi) with no discernible benefit. one and a half - I think I have a standard multimeter in the garage - would this be suitable for measuring mains voltage from the plug? How do I do that? Yes, the problem was there before I got the AR4. I had wondered if the AR4 might have helped - it did deliver some sonic benefits, but did not affect the hum!
  24. I can’t find ComputerAudiophile on Tapatalk - is it still there?
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