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 XX-2/AT
  • SUT / Phono Stage
    Kairsound/DIY tube
  • Digital Source 1
    PD stable platter
  • Digital Source 2
    Netbook
  • DAC
    Audiosector/buffer
  • Integrated Amp
    far, far too many
  • Pre-Amp
    DIY tube
  • 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

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  1. rabski

    Valve amp suggestions for Harbeth 40.1

    This. You're going to struggle to replicate what the 845s do so well. Possibly a really good 300B PP design, but that's likely to go well out of budget and the ones within budget are likely to sound like a step back. Very little else in the price range here has the sound that a well-designed 845 circuit can manage. If (and it's a very big if) you can find one, a Mastersound 845, but one that's been sorted. The filament supply board can be an issue. An even bigger 'if you can find' is the originally mentioned Puresound 845s. They use an interstage design rather than capacitor coupling, which drives the 845s much better. I've only ever heard a pair once, but they made mincemeat of most of the competition.
  2. rabski

    Do you need to spend much on a Multimeter ?

    Absolutely agree. I have an expensive soldering station, a decent oscilliscope and signal generator. And a £15 multimeter. I only spent that much because I needed a voltage range up to 2kV. The cheap ones are more than accurate enough for the vast majority of uses. Even for building things, there are very, very few times you need extreme accuracy.
  3. Not necessarily true. Any honest manufacturer will tell you that one of the reasons underlying the selection of electronic components is compliance with various directives, which rules out the use of NOS valves for a start. I am aware of at least two companies that have stated they ideally would have used different valves, but needed to fit new production types due to directives. AFAIK, both WEEE and RoHS have implications regarding the use of NOS valves.
  4. rabski

    Are you keeping your old stuff alive?

    I had a Kraken many years ago. I had mixed feelings about it. It had some serious grunt and a clean sort of sound, but seemed to get a bit muddled when you turned the wick up. I sold it in the end, because it didn't seem to do anything better than many of the alternatives and after a while the looks began to grate on me. Plus it certainly did run hot. Very.
  5. rabski

    Valve info

    As far as I know, it's one of the few without any real alternatives. In most circuits, 5692 will be OK, but it's far less common and unlikely to sound 'better'. Some sites suggest EL34 is a direct replacement, but it's by no means identical nor is the ECC32. The ideal grid bias is different and the heater current is higher. VT231 is the milspec 6SN7, but rare so costly. Some others are stated as replacements but arent, as they are not true double triodes, and have a common cathode. No equivalents with different gain, but that would normally be very unlikely anyway. Lower gain is sometimes possible, but higher gain inevitably means changes to the circuit, not the valve type. The good news is that there are almost endless flavours of 6SN7s around with different suffixes. So many that most are inconsistent in meaning. 6SN7GT should be a slightly better made version, but in most cases is probably the same. You can find 6SN7GTA, GTB, A, W, WGT, WGTA, WGTB and probably loads more. There is a Russian direct equivalent, but my list doesn't show the right number for it and a web search is inconclusive (Google is not always your friend). I think it's 6n8s in Cyrilic, but don't take that as gospel. As for what the different types sound like, I'm afraid I don't have a clue because I've never used them!
  6. rabski

    2020 Spreadsheet Now Live

    I've got a pair of 1930s half-wave mercury rectifiers I keep meaning to do something with, as a PSU for an insane pre-amp or low-power SE. However, possibly Kegworth is not the best place . Saturday night plus close to 2kV would probably not be the ideal combination...
  7. rabski

    Whest PS.30RDT Phono

    One other thing all Whest stuff seems to share is really excellent build quality. Even the back panel in the pic above is a real work of art. Oh, from limited experience, whey don't sound half bad either
  8. rabski

    Puresound P10 / EAR 834P into ADC?

    1: Basically, yes. 2: If they're right then it ought to be OK. I've got the 834 schematic here, and 'my' version shows the output is direct from the final tube cathode via a coupling capacitor. That should imply a relatively low impedance. That of course doesn't allow for potential changes to the circuit, which TdP is not unkown for. On that basis, I take back the 'none I know of', seeing as I've owned an 834, I should know better! If you can, see if you can borrow one. You can't damage it in the use you're looking at and it's an easy way to find out.
  9. rabski

    Puresound P10 / EAR 834P into ADC?

    If that's correct, it's slightly better, but still no good. 5k driving a 9k load is not going to work well at all. As above, the 'golden ratio' is a minimum of 1:10. A 5k output imedance needs accordingly to feed around a 50k input, which equates to the 47k mentioned originally.
  10. rabski

    Puresound P10 / EAR 834P into ADC?

    Definitely I'm afraid a very bad match. The general rule is at least 1:10, but in the other direction: low output impedance into high input impedance, and in fact the higher the better. The impedance stated for the RME is extremely low and no tube phono I'm aware of is going to drive that properly. With any valve circuit I can imagine, you'd need transformer coupling for it to work and I can't off the top of my head think of a tube phono with a transformer output. It would anyway be a very costly option. The specs don't seem to be available and I suspect it would be just as bad a mismatch to put the RME between the 25 and the 7. The possible answer would be a buffer between the phono and RME. There are assorted valve buffer designs with high input imedance and output imedance low enough to do the job. It's another box in the chain, but a solution. Otherwise, frankly keep the RME for digital sources and do without room correction for analogue. Probably not what you wanted to hear, but that's the way it is.
  11. rabski

    Twitchers Thread

    I've never had one that close before, though I've seen a few around in the local woodland. We get loads of wood pigeons here and in the early morning pre-coffee phase, it looked like a young one. Gave me a hell of a surprise when it turned round and I saw the eyes and beak! The bluetits and robins still are still feeding and it looks as though they missed any unwanted attention. Nothing could get at the blutits, as they're nesting in the gap at the top of a brick pillar under a balcony. I don't know where the robins are, but the relatively tame parent was happily by the end of my trowel while I was doing some weeding this morning and kept coming back for more bits of earthworm, so it seems all is well. The kites are amazing. They've become much more urban dwellers around here, and it's not unusual to see ten or more together above the town. Glad we don't have any small pets these days...
  12. rabski

    What's yer bits'n'bobs ?

    Excellent. Thanks for posting that. I've been looking for a suitable TT light and provided I can find a way to mount it (almost no flat area on the wall shelf) that should do perfectly.
  13. rabski

    Twitchers Thread

    Superb capture Keith. We have loads of them round here, but I've never yet managed to get a good picture. On a different note, I cursed not having the camera close at hand yesterday, because I looked out of the kitchen window and there was a sparrow hawk having a splash in our pond. Not sure whether to be pleased or not. We've got bluetits and robins nesting in the garden, though if it slims down the wood pigeon numbers I won't be too unhappy.
  14. rabski

    Random image of the day 3

    Another quick one. It's one of those places where the light makes it seem impossible to take a bad picture Sailing on Windermere by Richard Bowles, on Flickr
  15. rabski

    Pet Hates !!

    It probably is 'to share', trouble is, by the time it gets to the sharing bit, it's too late. It's odd. I can go for weeks without thinking about it or caring, but the moment I open anything with chocolate in it, I can't stop until it's empty. Doesn't matter what, or what size. I'll happily demolish an entire family-size box of anything in one go. Anne's nearly as bad, so I'll definitely pick up a bar or two of the heart of darkness. If she doesn't like it... Result!!