Not that I wanted to, but one of the E810F tubes (there are four) went microphonic to the point where i could hear it through the system. I isolated it to one pair (originally on the left channel) and when I switched that pair with those on the right, the tube noise switched sides. (I didn't have the patience to continue the process, nor at that point, any extra tubes of this type to figure out which tube of the pair was the culprit). Mr. Park, of Allnic, sent me a new pair. These were not Mullards, but Siemens, marked AEG, appeared to be NIB NOS.
Rather than have one channel of the 'stock' Mullards that were good and the other of the Siemens, I mixed pairs of the good Mullards and 'new' Siemens in each channel. Noise gone. (The noise was a high frequency squeal, or whistle that Mr. Park said, with further burn-in, would eventually go away). That was a little puzzling to me since i have at least 400 hours on the original set of tubes, probably a good bit more. The noise had only recently appeared, although you can hear the tubes singing in their sockets if you are near the preamp- it just did not manifest itself in the audio path until a week or so ago. I gather that these tube types tend toward microphony and thus the gel sockets that Allnic supplies with the unit.
Right now, things sound a little bright, it may be the newness of the Siemens and may be partly the inherent sound of the Siemens. I have no experience rolling this tube type, but with 6dj8 equivalents, in my experience the Siemens NOS seemed very linear but bright and less 3d and honeyed than the NOS Telefunken and not nearly as euphonic as the NOS Mullard (of that type).
I also found 4 NIB NOS UK Mullards which are, hopefully, going to be shipped from Eastern Europe. And a pair of US Mullards, NIB NOS (which I assume were made by Amperex). So, I'm rollin, whether I like it or not. By the time the UK Mullards get here, I should have gone through whatever 'burn-in' the Siemens required, so I may have a better understanding of what these different tubes sound like.
No questions really, unless anybody has some observations or experience with this tube type. I think one of the Kondo or Audio Note preamps may use it too.
I already quizzed a couple owners of the H3000 who said they have not had any tube noise problems. Of course, I'm using very efficient speakers so that may be part of the mix as well. More as it develops.
Rather than have one channel of the 'stock' Mullards that were good and the other of the Siemens, I mixed pairs of the good Mullards and 'new' Siemens in each channel. Noise gone. (The noise was a high frequency squeal, or whistle that Mr. Park said, with further burn-in, would eventually go away). That was a little puzzling to me since i have at least 400 hours on the original set of tubes, probably a good bit more. The noise had only recently appeared, although you can hear the tubes singing in their sockets if you are near the preamp- it just did not manifest itself in the audio path until a week or so ago. I gather that these tube types tend toward microphony and thus the gel sockets that Allnic supplies with the unit.
Right now, things sound a little bright, it may be the newness of the Siemens and may be partly the inherent sound of the Siemens. I have no experience rolling this tube type, but with 6dj8 equivalents, in my experience the Siemens NOS seemed very linear but bright and less 3d and honeyed than the NOS Telefunken and not nearly as euphonic as the NOS Mullard (of that type).
I also found 4 NIB NOS UK Mullards which are, hopefully, going to be shipped from Eastern Europe. And a pair of US Mullards, NIB NOS (which I assume were made by Amperex). So, I'm rollin, whether I like it or not. By the time the UK Mullards get here, I should have gone through whatever 'burn-in' the Siemens required, so I may have a better understanding of what these different tubes sound like.
No questions really, unless anybody has some observations or experience with this tube type. I think one of the Kondo or Audio Note preamps may use it too.
I already quizzed a couple owners of the H3000 who said they have not had any tube noise problems. Of course, I'm using very efficient speakers so that may be part of the mix as well. More as it develops.
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