Hi all,
5367 posts ago, Buddha asked for follow-up on the image of Keith Johnson's graph that I posted to the RMAF blog. His response follows. I suppose that if folks have further questions, I can lump them all together and send. But it would be best to both send them to me at my forum email box as well as post them, since it is a challenge to cull together questions from a myriad of forum postings and end up with something coherent.
--
Keith: I had presented a similar discussion for a Master Class - Friday, October 3rd at the 125th AES Convention in San Francisco. I think it was recorded and might be available.
I gave an example of how a piece of equipment with good stand alone performance might interact unfavorably with other components in an audio chain. Then power cords, signal cables and speaker interconnects might become part of a degradation path that could produce sonic changes from choices of wire and use of accessory gadgets.
A CD player, amplifier, speaker and cables were described as a problem system. Conspirator - culprits were a foil wound inductor in the speaker, torroid power transformer in the amplifier, and voltage regulator at the player. Such parts could have been good choices, but in this circumstance, an RF short or near zero impedance inherent from the speaker inductor and choice of speaker cable had initiated detrimental switching activity or "circuit rattling" from the amplifier. "Fuzzy" distortion might be heard. Scope traces revealed frantic millionths of second activity along with high frequency pulses that propagated through the power transformer to end up between power and signal connectors. In this example, disturbances passed through interconnect wires and on to player circuits to increase clock jitter and degrade signal accuracy.
Different power cords and their placement would modify path responses thereby changing disturbance at the player. Possibly one wire might sound different from another but the best solution was to fix the design problem. Then cords and interconnects were no longer an issue.
Hopefully, this somewhat abstract discussion might resolve questions.
Keith
Hi all,
5367 posts ago, Buddha asked for follow-up on the image of Keith Johnson's graph that I posted to the RMAF blog. His response follows. I suppose that if folks have further questions, I can lump them all together and send. But it would be best to both send them to me at my forum email box as well as post them, since it is a challenge to cull together questions from a myriad of forum postings and end up with something coherent.
--
Keith: I had presented a similar discussion for a Master Class - Friday, October 3rd at the 125th AES Convention in San Francisco. I think it was recorded and might be available.
I gave an example of how a piece of equipment with good stand alone performance might interact unfavorably with other components in an audio chain. Then power cords, signal cables and speaker interconnects might become part of a degradation path that could produce sonic changes from choices of wire and use of accessory gadgets.
A CD player, amplifier, speaker and cables were described as a problem system. Conspirator - culprits were a foil wound inductor in the speaker, torroid power transformer in the amplifier, and voltage regulator at the player. Such parts could have been good choices, but in this circumstance, an RF short or near zero impedance inherent from the speaker inductor and choice of speaker cable had initiated detrimental switching activity or "circuit rattling" from the amplifier. "Fuzzy" distortion might be heard. Scope traces revealed frantic millionths of second activity along with high frequency pulses that propagated through the power transformer to end up between power and signal connectors. In this example, disturbances passed through interconnect wires and on to player circuits to increase clock jitter and degrade signal accuracy.
Different power cords and their placement would modify path responses thereby changing disturbance at the player. Possibly one wire might sound different from another but the best solution was to fix the design problem. Then cords and interconnects were no longer an issue.
Hopefully, this somewhat abstract discussion might resolve questions.
Keith