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Recent content by snowman_al

  1. snowman_al

    Suggestions for a beginner's book on valves

    Basic Electronics (Vols 1 -5) can be down loaded from here: https://archive.org/details/BasicElectronicsVolumes151955/mode/2up It's old fashioned and covers way more than valves (tubes) but does give easy understanding. For a very quick read try : https://vacuumtubes.net/How_Vacuum_Tubes_Work.htm
  2. snowman_al

    Leak Stereo 20

    It will last as long as its fellows, as you say not uncommon for Mullard/Philips ECC8x to 'light up' at switch on. By the way the heaters are wired in Parallel across the 6.3 volt heater winding.
  3. snowman_al

    Is there a way to bypass naim phono boards

    Like this. Its really not necessary to use a wrap tool, a few turns of single core is fine.
  4. snowman_al

    There were these amps for sale, and well, I bought them...

    That could be worse... Ask Will he may have a replacement. (Or look out on ebay, but there are so may types...)
  5. snowman_al

    There were these amps for sale, and well, I bought them...

    It was the wiring colours I had in mind. In response to a ''complete rewire then?'' The chassis colours are often very slightly different shades and part of there charm as you say...
  6. snowman_al

    There were these amps for sale, and well, I bought them...

    That's a dilemma then... Do you make a matching pair, colour wise, or retain the different colours of the originals? Ummmm?
  7. snowman_al

    Leak Stereo 60 on eBay (Collect from Torquay)

    Reasonable Leak Stereo 60 at a reasonable starting price (I guess). https://www.ebay.co.uk/itm/295077849405?mkcid=1&mkrid=710-53481-19255-0&siteid=0&customid=link&campid=5338728743&toolid=20001&mkevt=1
  8. snowman_al

    HH Scott LK48

    Rewinds are beyond my skill level. Fortunately I know a man who tells me it is a complex wind.
  9. snowman_al

    HH Scott LK48

    This has been one of those slow renovations... But today the Scott is back in her case and playing in the lounge into the Dynaco a25s. Had a new 1000VA 120 volt step down transformer that does not dip below 117 volts. That showed the original output valves (4 Telefunken 7189s) would not bias up...
  10. snowman_al

    LEAK TROUGHLINE II , LEAK VARISLOPE STEREO , LEAK STEREO 20

    Have to agree with Avinunca. The only 'maintenance' I can see are the 4 replacement 400Ω 5Watt Radio Spares cathode bypass resistors, why when they did 270Ω ones? Otherwise original, so I doubt it is 'fully working'... Still a very nice example.
  11. snowman_al

    HMV valve amplifier

    Personally I would run it up on the variac and see what that brings before swapping out parts. It will not do any harm running 8 ohm speakers on either the 4 or 16 ohm setting, or 4 ohm speakers on the 16 ohm setting for that matter. Valve amps have a great tolerance to output impedances...
  12. snowman_al

    HMV valve amplifier

    Have a look at the 'top' section where the coupling caps are 0.1uF mustards. Some one has replaced them with 0.047uF poly caps for the 'bottom' section (?). This is obviously a pruned down version to the EMI unit, common cathode resistor, no grid stoppers etc. and removal of an ECC83... I...
  13. snowman_al

    Pair of Radford MA25 mono amps

    Normally KT66s do not have metal ring bases, and yes I know there are some recent Russian makes with them. It is a safe bet that all KT88s and 6550s do have metal ring bases.
  14. snowman_al

    HMV valve amplifier

    Here you go, HMV 557 circuit reverse engineered from what I /we can see. Please everyone chip in if you see an error or have a suggestion. I cannot see how mains earth or the chassis is connected to the bus bar. Also the circuit matches the bottom half of the picture, the ECC83 pin numbers swaps...
  15. snowman_al

    HMV valve amplifier

    As an aside, there are a couple of pictures of HMV599s online and they have another valve installed, where your example has a blank hole. I wonder if there was more than one type of 599?


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