He said..He said. How do we know the truth?. Well, why not make some measurements.
I put my PS Audio PS II outboard phono preamp (a high gain circuit that would most likely be affected by vibration) into a plastic hamper with a small speaker system and my calibrated SPL mic. I powered the speaker with a spare preamp and amp. For a signal (vibration creator)I fed in a 125 Hz warble tone. The two Behringer DEQ2496 (of my regular system) allow me to measure SPL (inside the box) and, simultaneously, the line out signal derived from the phono input coming from the outboard PS Audio preamp. Ideally this signal would be zero with no LP playing. The idea is to see how much signal can be generated by shaking the hell out of the phono preamp circuit.
Using the auxillary preamp, I cranked up the volume to 110 dB inside the box. Then I turned the warble tone OFF and ON, and observed the line out signal to be -77 dB rms in either case. In other words, the 110 dB SPL from a loudspeaker 3 inches from the circuit had absolutely no effect.
Then, to be sure that I was not making observations at too low a main system volume setting, I turned off the warble tone, relocated the mic to the listening room, and played a LP with the same volume setting (maximum)on my main preamp. The LP SPL for a moderately loud passage was 90 to 100 dB rms.
From this test I think I know the effect of vibration on an electronic circuit. What do you think? And why.
.
I put my PS Audio PS II outboard phono preamp (a high gain circuit that would most likely be affected by vibration) into a plastic hamper with a small speaker system and my calibrated SPL mic. I powered the speaker with a spare preamp and amp. For a signal (vibration creator)I fed in a 125 Hz warble tone. The two Behringer DEQ2496 (of my regular system) allow me to measure SPL (inside the box) and, simultaneously, the line out signal derived from the phono input coming from the outboard PS Audio preamp. Ideally this signal would be zero with no LP playing. The idea is to see how much signal can be generated by shaking the hell out of the phono preamp circuit.
Using the auxillary preamp, I cranked up the volume to 110 dB inside the box. Then I turned the warble tone OFF and ON, and observed the line out signal to be -77 dB rms in either case. In other words, the 110 dB SPL from a loudspeaker 3 inches from the circuit had absolutely no effect.
Then, to be sure that I was not making observations at too low a main system volume setting, I turned off the warble tone, relocated the mic to the listening room, and played a LP with the same volume setting (maximum)on my main preamp. The LP SPL for a moderately loud passage was 90 to 100 dB rms.
From this test I think I know the effect of vibration on an electronic circuit. What do you think? And why.
.