Alex 54

Wammer
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About Alex 54

  • Rank
    Junior Wammer

Personal Info

  • Location
    UK

Wigwam Info

  • Turn Table
    Townshend Elite Rock
  • Tone Arm & Cartridge
    Excalibur/Decca
  • SUT / Phono Stage
    Rega Fono MM MkII
  • Digital Source 1
    Linn KDSM Mk3
  • Digital Source 2
    Oppo UDP-205MR
  • DAC
    Linn KDSM Mk3
  • Pre-Amp
    Linn KDSM Mk3
  • Power Amp/s
    Nord One Up NC500 II
  • My Speakers
    Glastonbury Tor Mk1
  • Headphones
    Oppo PM-1
  • Trade Status
    I am not in the Hi-Fi trade

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  1. It's a plug-in fuse so if there are no sockets in the board to take it maybe it came from somewhere else on the PCB?
  2. Alex 54

    Coventry bakeoff - Sunday 28th April 2019

    Thank you for being a great host!
  3. Looks like a PCB mount fuse, should just plug back in.
  4. Agreed, you've got to try!
  5. They'll just say it wasn't packed properly, the original packaging is really the only way to be safe!
  6. Alex 54

    Coventry bakeoff - Sunday 28th April 2019

    Please add me to the list.
  7. Alex 54

    Heatsink Help!

    As a class A design it will be dumping a lot of energy into the heatsink, you need to find out exactly how much. I don't think 3 degrees/W will cut it, at 50W they would reach a temperature of 150C. If space is at a premium, you could go for a heatsink with integral fan cooling but you would need to have a thermal cutout in case of fan failure. It's also advisable to mount all the output transistors for each channel on the same heatsink so they are thermally coupled to compensate for drift problems.
  8. It was low frequency overload of the output transformers, all later models were fitted with a beefier transformer.
  9. Alex 54

    Lower voltage replacement capacitor??

    The lower voltage rating of the polystyrene capacitor is no problem, silvered mica capacitors generally have high voltage ratings.
  10. Alex 54

    Amplifier Schematic Review

    OK, so it is an inter-winding screen then.
  11. Alex 54

    Amplifier Schematic Review

    You were measuring the secondary, what I was referring to was what looks to be a centre tap on the primary in your circuit?
  12. Alex 54

    Amplifier Schematic Review

    Rather than an tap it's probably an inter-winding screen, a quick check with a meter will tell you if it's actually connected to the winding.
  13. Alex 54

    Amplifier Schematic Review

    Using two transformers give you separate power supplies for each channel which is a good idea. Don't think you have the mains input side of the transformers correct. Is there really a grounded centre tap on the primary? The triac is probably a soft start for the transformer but something is missing?
  14. Alex 54

    Are there any prefered Output Transistors?

    Since the circuit will have been designed to use those devices I would stick with them, Lambda have been used by a number of manufacturers including Pass Labs. Though obsolete, they can still be sourced if need be.
  15. Alex 54

    More Components for Identification!

    The 1N4148 are very common signal diodes. The ceramic disk capacitor is 330pF. The clear capacitor is probably a 39pF polystyrene. The resistor is more likely to be 33k Ohms, 31k is not a standard value.