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About Firebottle

  • Rank
    Junior Wammer
    Junior Wammer

Personal Info

  • Location
    The Black Country
  • Real Name

Wigwam Info

  • Turn Table
    Technics SL1200 Mk2
  • Tone Arm & Cartridge
    SL1200 DV Karat Ruby
  • SUT / Phono Stage
    Bigbottle 3
  • Digital Source 1
    Innuos Zen Mini Mk2
  • Digital Source 2
    Pure DAB 701
  • DAC
    Musician Pegasus R2R
  • Pre-Amp
    Bigbottle BT2 kit
  • Power Amp/s
    Neurochrome 286 dual
  • My Speakers
    ESL 57, REL sub
  • Headphones
    AKG Q701 lime
  • Trade Status
    I am not in the Hi-Fi trade

Recent Profile Visitors

494 profile views
  1. I use a simple 'loading' technique to guesstimate the output impedance. Firstly set the output voltage to say 1 volt, driving an open circuit or high impedance. Connect a 1K/2K variable pot and adjust the value until the output voltage is half of what it was. Measure the pot resistance, voila that's your output impedance.
  2. IME you have to use the best attenuator/volume control that you can, plus have it fed and buffered correctly to achieve best performance. My choice is a stepped attenuator, currently using an Acoustic Dimension that aren't available now. Unfortunately I see many expensive preamps and integrated amps that are using an Alps Blue as the volume control, such a bottleneck in some otherwise well designed kit.
  3. Yes, not impressed. Why not bolt the pass transistors to the case, instead of a silly little heatsink INSIDE the case?
  4. Another one that could be/may not be at fault. Fairly recently I have been finding caps that look like the one in the picture with what looks like a bulging top. However on further inspection (with ones finger) it turns out that the actual top of the cap is still perfectly flat, it is just the circular plastic cover that has distorted into a convex shape. Press the top to find out. I have checked values and dissipation factor and all have been OK apart from the plastic top distorting. Weird.
  5. Thanks for the invite Keith, it was good to meet new faces and see a comprehensive attack at active speaker design. As for those 18 inch drivers, ooh err missus.. The valve phono stage is a Bigbottle BB3. Real shame that we couldn't plumb in the Pegasus dac.
  6. I'd like to attend with Shirley if that's OK. I could bring a couple of phono stages (Bigbottle BB3 and Salas VPI) and a couple of R-2R Dacs (Musician Pegasus and Soekris 1321).
  7. It's all about the circuit implementation. As Andrew's link pointed out a CF is good if it provides a low output impedance driving a high input impedance. With voltage transfer (virtually all analogue connections in audio equipment) this is the best scenario.
  8. Under certain circumstances, particularly driving quite a low impedance, the cathode follower can go into a type of 'blocking' mode at power up. It makes a strange type of squealing noise. I have experienced this, the usual cure is to include a 100 to 220 ohm series resistor in the output line.
  9. If you have 50V on the grid that points to a grid-cathode short on the 300b. What voltage do you have on the cathode? Should be around 50V from experience. @rabskiPerhaps the 15uF is for hum cancellation?
  10. Max A$$hole is absolutely right. Lewis was ahead and Max decides to go for a non existent gap on a chicane, nuts. I would have loved it if Lewis had been able to reverse out and continue the race to get ahead with some more points.
  11. I had the Topping D90 previously and the Soekris was a total eye opener for clarity, detail and pin point imaging.
  12. Has anyone compared the Ares II, or any other R-2R Dac for that matter, to any Soekris dac, particularly the 1321? The 1421 is the balanced version but unfortunately is killed by the inclusion of a switch mode power supply. Once this is replaced with a linear PSU it is very good also.
  13. Southeastern, where is that rocket going on your avatar?
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