Recent content by pma

  1. pma

    What is on your workbench right now?

    My preamp built in 2003.
  2. pma

    The Truth Pre Amp Review

    Every competent user is able to compress the image <1MB. The cry is not needed. I posted tons of images here and feel no restriction by the 1MB limit. Learn and grow, it is my recommendation. And stop trolling.
  3. pma

    Jensen ISO-Max CI-1RR Review (Isolation Transformer)

    I measured this CMR on a DIY signal trafo made by a colleague. Looks similar like Jensen result posted by @SIY . I bought it at about $80.
  4. pma

    Jensen ISO-Max CI-1RR Review (Isolation Transformer)

    -10dB/decade noise floor slope is interesting. What is the reason?
  5. pma

    Jensen ISO-Max CI-1RR Review (Isolation Transformer)

    Simulated CMR of signal transformer with source resistance as a parameter. primary winding resistance = 40 ohm secondary winding resistance = 70 ohm primary/secondary capacitance = 2 x 1nF secondary parallel capacitance = 200pF source resistance = 1 ohm, 50 ohm, 1 kohm load impedance = 4 kohm...
  6. pma

    Jensen ISO-Max CI-1RR Review (Isolation Transformer)

    Link transformers need deep and thorough understanding to give their best. This applies to source and load impedance, stray capacitance, floating/grounded sources and balancing of source and load impedance. Please see the trivial example where the link transformer is put into a soundcard...
  7. pma

    Jensen ISO-Max CI-1RR Review (Isolation Transformer)

    This is an error of your arrangement. When you use a signal transformer, the I/O’s must not be floating, otherwise you have the hum components through stray capacitance. Try the grounded source and the problem should disappear. The best result is if both input and output are grounded and the...
  8. pma

    Fast transient in music recordings - tweeter load - amp response

    0.8FS and 0.6FS are correct guesses. And? All I am saying is that peak amplitude into tweeter section is high, nothing else. Because this is often overlooked and not understood.
  9. pma

    The Truth Pre Amp Review

    I really believe I do so, quite often. The more specific and niche you are, the less you get.
  10. pma

    The Truth Pre Amp Review

    Or tube circuits link stages, Sir, to return a compliment ;).
  11. pma

    The Truth Pre Amp Review

    Why this poor design is getting so much attraction. Serious audio topics are disappearing from ASR. This seems to be a saga of every audio forum.
  12. pma

    Fast transient in music recordings - tweeter load - amp response

    This is the measured spectrum of electrical signal at amplifier output and acoustical signal corresponding to time domain plots in post #21. 5 cycles of 6kHz sine have length of 833.33 us. This corresponds to 1200 Hz width of the side lobes. Sine burst was generated with Fs = 48kHz (see the...
  13. pma

    Is there an Audible / Measurable Difference between RCA and 3.5mm Connection?

    All about contact resistance and proper measuring method. AP is sometimes used as a cannon to shoot the sparrow.
  14. pma

    Is there an Audible / Measurable Difference between RCA and 3.5mm Connection?

    This one looks good, indeed. And the price is then adequate, no bargain. I was talking about those usual 3.5mm jacks used in cheap audio toys.
  15. pma

    Is there an Audible / Measurable Difference between RCA and 3.5mm Connection?

    I have not met a single 3.5mm jack that would not have contact issues as a link cable, talking about decades of experience. Good for nothing but DC and even then not very reliable.
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