Recent content by mugdecoffee
  1. mugdecoffee

    Valab NOS DAC, did I butcher it? EXPERT needed.

    A 4.7uF output cap is plenty.  Into a 10kohm load which is hopefully as low of a load as it'll ever see, it has a bottom cutoff frequency of 3Hz.
  2. mugdecoffee

    Portapro Recable commissioning?

    Quote:   I think the problem is the cans not the cable.
  3. mugdecoffee

    my DAC design - pup1 DAC

    Just got my board today and ordered my parts.  When I got the board today with the two chips, I realized I only paid $5CDN for the whole package.  Do I own someone another paypal payment?   EDIT: also the 1Mohm resistor spec'd in the BOM is now obsolete. I forgot to replace it with something...
  4. mugdecoffee

    my DAC design - pup1 DAC

    Does the IV opamp put out enough power to drive headphones directly do you think?  Is the power supply robust enough to handle such a load?  This would make a really cool single board solution for portable listening.
  5. mugdecoffee

    Where did you learn about DIY Audio/Electronics

    While not very efficient, I learned a lot just by following threads here and picking up bits and pieces.  If you don't quite understand voltage, current, resistors, capacitors, etc, you could probably google around to find a basic electronics introduction online.  I've also gleaned a far bit...
  6. mugdecoffee

    A Very Compact Hybrid Amp

    It would be great if that were added the the CTH main site.  I remember spending 30 minutes more than once trying to track down that spreadsheet and it'd be annoying to have it become buried again.
  7. mugdecoffee

    Bijou All Tube Futterman Headphone Amplifier

    Quote: You could string together 4 25k 1/4 watt  resistors in series which would be much easier to find in a parts box.
  8. mugdecoffee

    Help! How to recable UE TripleFi (IEM)

    Quote: I think the biggest reason is that solid core wire is stiff and people tend to move while wearing IEMs.  Beyond that, solid core wires can break easier.  In a stranded cable, the individual strands are more flexible and even if a couple do break at a point, other strands can carry...
  9. mugdecoffee

    Cavalli Compact Tube Hybrid (CTH) Tube & Tweak thread.

    Is there a way to reduce the gain of this amp?  I'm already using a 100ohm output resistor and find myself using the bottom 15 degrees of my pot at most.  Even with a nice pot, the channel matching is poor at the very bottom end.  I'd also like to not use the output resistor since its probably...
  10. mugdecoffee

    Is ripple the only spec we care for in an "audio source" PSU?

    Output impedance also matters.  If a PSU has a high output impedance, the voltage will drop when large amounts of current are drawn.
  11. mugdecoffee

    Convert Optical to USB

    I think you could make a similar cable without the optical conversion by replacing the USB power rails with an external supply.  So, the two data lines go from USB to USB and the output USB is powered from an external 5V.
  12. mugdecoffee

    Volume pot question

    Changing the value of the pot actually doesn't change its attenuation at all.  Instead you could try putting a resistor in front of the pot which basically always attenuates the signal some before you even adjust it.   Also interconnects should never affect the volume unless there is...
  13. mugdecoffee

    Post pics of your builds....

    Quote:   After you place the resistors and such in the perfboard, how do you solder them without flipping the board and having them all fall out?  
  14. mugdecoffee

    Cavalli Compact Tube Hybrid (CTH) Tube & Tweak thread.

    Just replaced my Alps RK27 pot with a TKD 2CP-2508 and the improvement is astounding.  While it was expensive, I'd definitely recommend it for someone's upgraded the caps and has a nice tube in their build already.  The bass is much tighter and deeper though that might be because I went from a...