Recent content by skip129
  1. skip129

    M-Audio Fast Track Ultra vs Fiio e7 DAC

    NwAvGuy is apparently going to publish a review of some pro USB audio interfaces, which should be very interesting.   FWIW, I have the Fast Track Ultra, and I have measured the output impedance of the headphone output at about 2.5 ohms, which is pretty good. (if my measurement is accurate -...
  2. skip129

    Meier audio corda 2stepdance, Is it a good synergy with the HD600 and UM3X?

    Ah ok - agreed in that case. (however I have no experience with the 2Stepdance or the UM3X - I can't say for sure how they will sound together, but there should be absolutely no problems with volume level, going by the specs)   Greg.
  3. skip129

    Meier audio corda 2stepdance, Is it a good synergy with the HD600 and UM3X?

    The thing that lets the 2Stepdance down IMHO is it's maximum gain of 14dB. (I'm going from memory here - the site is down at the moment). If your portable device has a typical 0.5V RMS output, that will produce a max SPL of about 110dB, which is pretty loud, but I have read that sometimes a...
  4. skip129

    Musical Fidelity V can Mk II

    I've got the MK I, but the specs look the same.  I don't have much to compare with, but it sounds fine, and the same as the headphone output of my hi-fi amp. The hi-fi amp has a very high output impedance, but my headphones have a flat impedance vs frequency curve, which is why the V-Can sounds...
  5. skip129

    FiiO E17 "ALPEN" - First Impression + Final Thought

    I contacted FiiO and asked them what the maximum output power is when operating as a USB amp - they said 32mW into 300 ohms, so that brings the HD600 SPL up to 112dB SPL.
  6. skip129

    Why aren't portable amp makers more open about output impedance?

    I have read somewhere (in that same standard, I think) that one reason the 120 ohm output impedance is recommended is simply to reduce the discrepancy in volume between headphones of different impedances. (which it would). It went on to say that headphones generally have a rather constant...
  7. skip129

    Why aren't portable amp makers more open about output impedance?

    I agree.   Just a word of caution though - it appears that Beyerdynamic design most of their headphones to be used with a high output impedance amp (120 ohms), according to standard DIN-EN 60268-7, which specifies that the output impedance should be 120 ohms.  I contacted them, and they...
  8. skip129

    Would a Fuse Rockboxd and Grado igi IEMs benefit from an amp? Not sure how to interpret sensitivity/impedence numbers for IEMs/phones...

    I have no experience with either, however my understanding is that the Fuse has a very good quality headphone output, with a very low impedance, and would be able to generate approximately 10mW into those phones, producing an SPL of 115dB, which is very loud.  So my educated guess is: no amp...
  9. skip129

    amp for AKG Q701

    I think the worst thing I've seen about the E9 is that in a test, it had a channel imbalance of 1.8dB, which seems a bit high, but not terrible.
  10. skip129

    amp for AKG Q701

    Quote: Looking at the impedance vs frequency plot here:  (specs tab), my gut feel is that the affect of the output impedance of the E9 would be extremely subtle. I think the recommendation is at least an 8:1 ratio of headphone...
  11. skip129

    Low Impedance Headphone Amp?

    If you look at the impedance vs frequency plot of the ATH-M50 at it doesn't seem to vary much with frequency, which means the output impedance of the amp won't have a large affect on the tone. (it may still have some affect)  I have...
  12. skip129

    New Products from Firestone Audio -- the FireKey Line

    Is there a website with more info? I am particularly interested in the USB filter. (GreenKey). 
  13. skip129

    iBasso D6 "Fer-de-Lance" USB DAC/Amp

    Maybe we need a "loudness" index, that is a more accurate specification for the genuine loudness of a headphone. The sensitivity/efficiency might be too simplistic.   Thanks for the info paulybatz - much appreciated.   Greg.
  14. skip129

    iBasso D6 "Fer-de-Lance" USB DAC/Amp

    Nice one, although I'm totally perplexed that it could sound as loud as your Grados on nearly the same volume position!   Has anyone tried AKG K601 headphones with the D6?    
  15. skip129

    FiiO E6 Amp question

    Apparently the iPhone4 may have a very low output impedance (not 100% sure) -  if this is true, and they are already loud enough for you, I'd say there would not be any improvement, and adding something in the chain may even make it a bit worse.  If you want the bass boost, though, then by all...