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About Firefox

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    Evil Keeps Me Young

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  • Headphones
    Beyer D. DT931 Sennheiser HD270 Sennheiser HD570
  • Sources
    Pioneer CLD-2750K (modded) Pioneer PD-S904 (modded) Arcam Alpha 1
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  1. Firefox

    CK2III help

    Check the values of R2 through R6. Make sure they match up nicely. It appears that your front end is the problem. If all lines up then you probably have an issue with either the input fets or C1 through C4 (check that they are not damaged).
  2. Just a bit of advice, it's not a good practice to do so. The earplugs will keep your ear canal warm and moist. Perfect breeding ground for bacteria and viruses. Perhaps a bit of soothing, ambient music played over speakers at very low levels would do better?
  3. No, not quite. Well Audio *might* have some but the pricing is significantly higher. Visit team108's (distributor) website for their address and head down to get the cable. They're located at Tannery Lane (near Macpherson).
  4. Does it push out the Jawbone? Since the Jawbone actually relies on direct contact with the jaw to pick up the vibes.
  5. Here's a tip for working with casting epoxy: hair-dryer. The heat causes the air in the bubbles to expand and they will rise to the surface and pop. My buddy and I used to use lighters to achieve the same effect (but for flat cast items). For something like that, use a hair dryer instead. On the note of the mould, go get mould release wax (should be available from art friends too). Then the epoxy won't stick to the mould and you won't need to clean residues off with spirit.
  6. Firefox

    toMMo amp

    Hrmm.. That's an inverting configuration which can, on a simple design like this, sound much better than the non-inverting equivalent. As for the LED, calculations need to be made for the LED's Vf and the resistor value changed accordingly. Also, note that the Vf limits how low the battery voltage can drop before the V-gnd swings to the top rail. It might be better to simply implement an inexpensive opamp as a unity gain buffer to drive the virtual ground. The opamp presents a high impedance to the resistor ladder and that prevents the mid-point from fluctuating too much since the current fluctuations through the ladder is minimized greatly as opposed to charging/ discharging the capacitors directly. Alternatively, a simple transistor configured as an emitter-follower would also do well to isolate the ladder from the current fluctuations of the capacitors charge/ discharge.
  7. It is not recommended. For starters, the amp is not in unity gain, which is what you need for the ground channel. Secondly, even if you had the 12AU7 in a cathode follower configuration, that design does not have global feedback, which is what you need to ensure that the currents on the ground channel are always balanced.
  8. It is correct. The 2 LM317's are not configured as voltage regulators. They are configured as Constant Current sources. Hence, by calculation, each of them are sinking 1.25v/( (15*20)/(15+20) ) = 0.146A. Therefore, instead of driving the filament with a fixed voltage and obtaining the current flow by the resistance of the filament, both current sources sink nearly 0.3A together through the filament. This negates the need for a separate voltage source/ regulation for the filament. A regulated supply connected across the filaments would stabilized at a fixed current after warming up but this design allows for regulated current through the filament regardless of the voltage supply.
  9. That's odd.. I'm sure I see many on the bus and trains everyday.. Most of them congregate at STOMP forums too..
  10. I was kinda guilty of dragging Adrian into the headphones thing actually.. Lol.. Knew him from before that when we participated in other local computing forums. The first gathering was actually at Rameish's place. The 2nd was at AMK at Pipee's brother's place. 3rd meet was at Singapore Poly Guildhouse courtesy of Mr Leng.
  11. You can buy replacement pads from Hung Brothers. They're about $40 a pair. Ask for the DT770/ 801/ 831/ 901/ 511 pads if they don't seem to know about the 931 pads. They're essentially the same but most retailers don't stock the pads listed for 931's.
  12. Firefox

    DIY-ed cables

    Nice touch on the cables. The Y-split is interesting though. I had no idea that it is even available locally.
  13. Hehee... Quite obvious who she is..
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