rabski

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About rabski

  • Rank
    Moderate to fair
  • Birthday Private

Personal Info

  • Location
    Kettering
  • Real Name
    G. Rumpty Git

Wigwam Info

  • Turn Table
    Well (bad) Tempered
  • Tone Arm & Cartridge
    Dynavector XX2/AT-F2
  • SUT / Phono Stage
    Kairsound/valve DIY
  • Digital Source 1
    PD stable platter
  • Digital Source 2
    Computer/M2Tech
  • DAC
    DIY AD1865/A.Sector
  • Integrated Amp
    A few
  • Pre-Amp
    DIY valve + assorted
  • Power Amp/s
    845 SET + too many
  • My Speakers
    Living Voice IBX R2
  • Headphones
    AKG
  • Trade Status
    I am not in the Hi-Fi trade

Recent Profile Visitors

3,660 profile views
  1. rabski

    Does rfi makes a system sound brighter?

    No. I'm out. I don't waste my time being wound up by arrogance and ignorance. Actually it's quite funny to be told I have 'no understanding' by someone with absolutely no idea of what I do or don't know.
  2. rabski

    Does rfi makes a system sound brighter?

    Seems amazing to me that so many chip manufacturers have gone to such great lengths to elminate a problem that does not exist. But still, compared with you, I have 'no real understanding'. I will therefore bow to your superior knowledge of electronics and bow out of this thread.
  3. rabski

    Does rfi makes a system sound brighter?

    Instead of asking me, why not look it up, Shadders? All of the pieces I have quoted there are from research papers. The people carrying out the research obviously considered it a problem, or they would not have investigated it. The fact that they have, suggests it is a problem that has been encountered. Your 'nobody has presented any evidence' is ridiculous, when it is apparent that there is lots of it. The one who has presented no evidence other than 'I say so' is actually you.
  4. rabski

    Does rfi makes a system sound brighter?

    With respect, you are guilty of what you accuse others of. It is your opinion, not fact. If you take the simple step of typing 'effect of RFI on electronics' into Google, it appears many do not agree with your opinion. I am not taking a position either way, because as I have stated already, I don't know. I can, however, quote a few things I have found in peer-reviewed, published papers that are interesting: "Unfortunately, RF rectification occurs because even the best in-amps have virtually no common-mode rejection at frequencies above 20 kHz." "Several studies, experiments and calculations have shown the propensity for operational amplifiers to demodulate RF signals principally at the emitter-base junction of the input differential pair." "EMI can enter a system (or device) through either conduction, radiation or both. Radiated EMI is most often conducted by Printed Circuit Board (PCB) traces or wires that lead to active devices, such as op amps. The physical length of these traces and wires makes them effective antennas at microwave and Radio Frequencies." "As a result, many extra frequencies, including the demodulated baseband of the interfering signal, occur. Nonlinear circuits include those that depend on feedback to reduce distortion. At higher frequencies, the feedback effect is nonexistent, and the system does not suppress RFI."
  5. rabski

    Does rfi makes a system sound brighter?

    The mids from a good DHT SET are certainly spectacular, but bass and top end don't have to be compromised. That's usually based on experience with cheap transformers or designs.
  6. rabski

    Does rfi makes a system sound brighter?

    It's strange, TdP is actually an excellent designer, but sometimes I genuinely think he likes to do things 'despite' rather than 'because'. Has to be said, mind, that he gets hellishly good results a lot of the time. I'm no great fan of the 834, but the 912 is pretty much a reference grade phono stage.
  7. rabski

    Does rfi makes a system sound brighter?

    The Olympians I believe 'measure' extremely well, but Kevin is no fool when it comes to design and I know that a massive amount of effort has gone into things like precise time alignment. On the other hand the 'old' favoured combination with Kondo may well be another matter entirely. I doubt they measure badly in any way, but Kondo never cared much about minimising even-order harmonic distortion. As for the preference, I am specifically thinking about a particular DAC that should remain nameless. It apparently measured/measures close to perfection and like an idiot I bought it on the basis that it ought to be good if it cost that much. I think I am far from the only one to have come to the conclusion that it was capable of stripping paint. 'Harsh' doesn't begin to tell the story. I found it absolutely unlistenable, but then lots of people seem to prefer some brands of speakers that have the same sort of presentation.
  8. rabski

    Does rfi makes a system sound brighter?

    Conversely, probably the most 'realistic' (in the sense of 'being there') system I have ever heard doubtlessly measures relatively poorly in terms of some distortion. I have heard plenty of equipment (and accidentally owned some) that is supposedly extremely accurate. You're welcome to it.
  9. rabski

    Does rfi makes a system sound brighter?

    At last, a mention of someone who really knows what they are talking about.
  10. rabski

    Does rfi makes a system sound brighter?

    Alice in Wonderland time again (not you Steve)
  11. rabski

    Does rfi makes a system sound brighter?

    Nah. Same length. Same mains plug and IEC. Touches neither cloth nor carpet I can think up some insane mega-foo theories, but the only one that makes the smallest bit of sense to me is that the old one was a sort of woven construction, so possibly throwing out a fair bit of crud. The preamp is on the shelf above. However, it's in a grounded metal case and all the interconnects are shielded. Plus, the difference was with the preamp gain set to zero. Only the gain on the power amp...
  12. rabski

    Does rfi makes a system sound brighter?

    How would it do that? The construction people are suggesting is for the screen to be connected at the supply end only, and to mains earth. It seems likely to me that this would be an efficient way to ground anything. I'm not saying that there is or isn't anything to ground here, but I don't see how screening an earth cable would do what you suggest.
  13. rabski

    Does rfi makes a system sound brighter?

    1: Absolutely. There are good and bad amplifiers, sources and speakers. The actual topology is mostly irrelevant. 2: True. But I bet it 'measures' perfectly...
  14. rabski

    Does rfi makes a system sound brighter?

    Not sure what your point is. Apart from the crossover slopes and possibly the room nodes, all of those topics can sensibly be addressed without resorting to piles of graphs and measurements. The impedance matching answer requires a number (1:10 being ideal), but nothing else. I am no way anti measurement, but unless it's really necessary it rarely aids comprehension, but instead adds confusion. There are some classic examples in this current thread of graphs being added to illustrate an entirely irrelevant matter, but as far as I can see, no graphic illustration to deal with the actual issue.
  15. rabski

    What are your 6 favourite Album Covers?.

    Very difficult to separate it based on just the cover, rather than the content. Probably change my mind later, but six of the best IMO from my unruly pile