Bit of a long shot this but I wonder if anyone ever built a preamp using these boards? I bought my boards over 10 years ago and only recently got around to putting it all together.
I just wondered what others thought of the SQ and whether they had done any modifications. I am very happy with it even though it is barely run-in.
Rob.
I just wondered what others thought of the SQ and whether they had done any modifications. I am very happy with it even though it is barely run-in.
Rob.
Any amplifier or audio stage with electrolytic capacitors will run in. i.e. the sound quality will alter with use as ions in the the capacitors' electrolyte diffuse, migrate, and interact with the dialectric layer over hours to days of use.
Electrolytics that have been stored for years without charge will not initially meet specification as the dialectric breaks down without charge and has to be reformed.
This is a problem for electrolytic capacitors in interstage coupling between audio stages at nominally the same voltage. Over time the capacitor deteriorates. One means to prevent this degradation was used by Peter Walker of Quad fame; he ensured the audio interstage coupling capacitors were pulsed with voltage of the correct polarity every time the unit was turned on.
Temperature effects also come into play affecting sound quality over the short term time frame of minutes to hours.
Whether the changes will be audible depends on whether those subtle changes are swamped by noise and distortion, for example, as well as the hearing acuity of the listener.
Electrolytics that have been stored for years without charge will not initially meet specification as the dialectric breaks down without charge and has to be reformed.
This is a problem for electrolytic capacitors in interstage coupling between audio stages at nominally the same voltage. Over time the capacitor deteriorates. One means to prevent this degradation was used by Peter Walker of Quad fame; he ensured the audio interstage coupling capacitors were pulsed with voltage of the correct polarity every time the unit was turned on.
Temperature effects also come into play affecting sound quality over the short term time frame of minutes to hours.
Whether the changes will be audible depends on whether those subtle changes are swamped by noise and distortion, for example, as well as the hearing acuity of the listener.
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Have you measured this happening for real? Espeically in low voltage low impedance solid-state circuitry where leakage current noise is unlikely to be problematic. Re-forming is not something to worry about I reckon (unless you have decade-old 400V 10mF monsters to commission!).
Dialectic and dielectric are very different words BTW!
I am speculating what causes capacitors to have clearly audible 'sound' that changes. One day it will be quantified and measured, if it isn't already. Why do so many companies make audio grade capacitors?
Expectation bias works both ways, you know. I started with a tertiary education in electronic engineering and found it easy to disregard effects that seem trivial, and know you cannot hear things you don't believe in.
My experience changed when as a professional audio engineer I started constructing double blind listening tests and learned to overcome my own biases - I started to hear things that once as an electronic engineer I didn't believe happened.
BTW picking on spelling mistakes, whilst fun maybe, isn't really advancing the topic.
Expectation bias works both ways, you know. I started with a tertiary education in electronic engineering and found it easy to disregard effects that seem trivial, and know you cannot hear things you don't believe in.
My experience changed when as a professional audio engineer I started constructing double blind listening tests and learned to overcome my own biases - I started to hear things that once as an electronic engineer I didn't believe happened.
BTW picking on spelling mistakes, whilst fun maybe, isn't really advancing the topic.