Jump to content

1bit

Senior Member
 View Profile  See their activity

  • Content Count

    168

  • Joined

  • Last visited

Posts posted by 1bit

  1. Posted · Report reply

    Edit: Sigh, the connections at the pot are all loose, giving me problems, hard to solder there...

    Waa

     

    sharing my soldering experience with you

    if you're trying to solder the pins to wires, it's easier to put small amount of solder on both the pin and wire. later you just need to bring them close together, heat both wire and pin with your soldering iron and let the solder flow, remove soldering iron, and hold the wire in place for a while until the solder harden

     

    hope it helps

    practice makes perfect

  4. Posted · Report reply

    the thing about TL072 is that it has a rather high DC offset, more than 5mV. Yes it's still considered quite small, and perhaps still tolerable by your headphones.

    opa2227 on the other hand has a very good DC performance, it is a precision opamp after all.

    TL072 is a generic dual FET input opamp.

    iirc TL072 has a better slew rate performance

    max output current is about the same iirc about 20 mA

     

    Probably another difference is in terms of noise and THD, and personally (and biased) it's kinda icky using TL072 an old opamp in a design lol

  5. Posted · Report reply

    while it is possible to find datasheet online and ask people in the forum, another solution for answering the questions about the potentiometer pin is to test it out yourself using an ohmmeter.

     

    i know it's probably quite a hassle for a beginner to even considering buying a multimeter, then there's also that learning curve for using measuring equipment. but trust me, a multimeter is really a great help for diy.

     

    and it makes diy-ing much more fun, not mentioning more scientific as then you are able to measure electrical parameters in your amp and see for yourself the improvement that different components or circuit topology brings to your amp or any other circuit in general.

     

    oops sorry a bit out of topics.

     

    anyway good luck with your diy. i hope it is successful and you have fun with it.

  12. Posted · Edited by 1bit · Report reply

    yeah you really need the led resistor, if you don't put it in, the led will draw so much current that the battery won't last long. the resistor there will control the current.

     

    For 9v battery, the resistor's value can range from 560 to 10k ohm, depends on how bright you want the led to be. Try to use as high value as possible though.

     

    a little comment: you should probably add more detail on how to solder those jumper wires (the green links in your diagrams) i think beginners might get confused about this. Actual photos would be nice.

     

    another thing, metal film resistors (usually blue colored) would be more suitable for an amp. it's still quite cheap at 10 cents a piece iirc.

     

    i love the way you put pictures to describe the parts list. but looks like the actual audio jacks that you use is different from the picture.

     

    and the main point is that you give a nice layout that is easy to solder the jumper wires (no messy wire crossings)

     

    cool

  14. Posted · Report reply

    i think in general they refer to the same thing

    in this discussion thread we use optical to refer to the optical cable, i mean the whole assembly of the cable.

    fiber optics usually refer to the component inside the cable that is the medium that transfer laser beams.

    and fiber optics is also used to refer to a type of connection in computer networking

    (correct me if i'm wrong)

    the correct way to call this cable is TOSLINK cable

  16. Posted · Report reply

    about a year ago i bought an optical cable with interchangeable plug between the standard square plug and the mini plug at sim lim square.

    the shop is at the first floor, at one of the corner. i thik the shop also sells camera or other electronic stuff. the cables are put on the wall.

    it's about $20-30 iirc.

  19. Posted · Report reply

    Well, if you can find a 4pdt with centre off switch that'll be better. Basically it has 12 pins, you wire the centre 4 pins to the amplifier R+, RG, L+, and LG. The side pins to the respective source.

     

    The centre off means that the switching will not be direct from source A to B but there's a middle position that's actually an off position, the amplifier will not be connected to any source. This will make hot switching safer.

  21. Posted · Report reply

    when using a lineout of player, still can control how the song sound by fine- tunning the equalizer?

     

    Most probably the equalizer is a digital equalizer, the equalization is performed before DAC. I think it's quite difficult to find portable players with analog equalizer nowadays. Going digital is cheaper, smaller, power efficient, and can be finetuned more easily than analog parts.

  23. Posted · Report reply

    These 2 items are out of stock :

    aluminum electrolytic capacitor 470µF 16V Farnell 1219462

    aluminum electrolytic capacitor 100µF 25V Farnell 1219466

    Anyone can recommend other places to get them? :lust:

     

    Thanks

     

    I think the 470uF Panasonic FM are still available from farnell, 17 left in uk warehouse, but you need to order 5 minimum this time

     

    the 100uF FM has been out of stock for quite a while

    i'm using the rubycon zlg for this. it's also a low esr caps like the FMs

     

     

×
×
  • Create New...