The magic words I saw were "takes time to recover." The concern appears to be clipping activating some unknown and possibly bad clip recovery characteristic of the opamp(s)/gain stage(s) used, making a tick "extended" in pulse width or otherwise worse than if it were accurately reproduced. I can easily see this sort of thing happening with a tick/pop driving a transistor into saturation. Opamps have lots of transistors, and I don't recall seeing anything to keep those opamp transistors from going into saturation, as there are in the Shottky-diode-clamped transistors in LSTTL chips.
Without knowing time and amplitude of the 2 spikes its hard to be exact. Wider pulses mean more lower freqs ( the extreme being a step response which has all of its non dc component in the rise only) which are not as audible, and not as hard on your tweeters. So a narrow spike thats 10bd hotter than a wide spike will sound worse and be more likely to damage your speakers.
Good evening all, one of those kind of 'real world' experiences tonight when I was listening to some Villa-Lobos Classical guitar on vinyl tonight, a recording with some 'scratches' but nothing too severe, and it occurred to me that if your records have such bad scratches so as to cause problems in the phono stage, perhaps the records are best thrown out! Regards, Felix.
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It seems to me the purpose of the phono preamp is to amplify and reproduce what happens at the stylus (with, of course, proper EQ) with full dynamic range, whether what is picked up by the stylus is intended or not. This can allow further processing to achieve the best potential such as an A/D conversion and digital declicking.
The amplifier and speaker should be able to be "look out for themselves." If limiting is needed, it should be somewhere in there where the gain staging to the driver is fully know, as opposed to being before the volume control. Driver protection can be done here, especially in modern designs with powered speakers where the amplifier and driver are designed with each other in mind, a circuit (or more likely) microprocessor can calculate a close approximation of a driver's voice coil temperature, and what the driver's limits are (both in instantaneous power and in average power), and reduce the level to prevent damage.
As to throwing out an overly scratched record, I have no problem doing this, presuming I don't want to listen to the music, or I've gotten a better replacement. Sometimes the recording has historic or other special value. If it's an acetate it's likely the only recording of that performance, and "Elvis has left the building." In such a case one wants the best reproduction of the recording as can be done.
Generally speaking, a bad recording of a famous person or excellent musical performer is much more desirable than a good recording of an unknown and/or bad performer.
The amplifier and speaker should be able to be "look out for themselves." If limiting is needed, it should be somewhere in there where the gain staging to the driver is fully know, as opposed to being before the volume control. Driver protection can be done here, especially in modern designs with powered speakers where the amplifier and driver are designed with each other in mind, a circuit (or more likely) microprocessor can calculate a close approximation of a driver's voice coil temperature, and what the driver's limits are (both in instantaneous power and in average power), and reduce the level to prevent damage.
As to throwing out an overly scratched record, I have no problem doing this, presuming I don't want to listen to the music, or I've gotten a better replacement. Sometimes the recording has historic or other special value. If it's an acetate it's likely the only recording of that performance, and "Elvis has left the building." In such a case one wants the best reproduction of the recording as can be done.
Generally speaking, a bad recording of a famous person or excellent musical performer is much more desirable than a good recording of an unknown and/or bad performer.
G'day mate, yes good point. Likewise I have some records like a rather scratched copy of a Beatles album that has one of my all time Beatles favourites 'Strawberry Fields Forever' on it, and yes although it is quite scratched I will never throw it out because I love that song and the record itself has enormous personal sentimental value to me! Regards, Felix.
The purpose of phono preamp is to amplify and reproduce MUSIC.
Ever accidental bump your TT or drop the needle too hard. Would you want that to fry your tweeter.
It makes little sense to me to expect your system (or even parts of it) to reproduce defects at full output, when they can be more than 10 dbv over the max level of the music (thats 100 times the power). Is the stylus not hard clipping to start. Your solution of a microprocessor to do almost the same job as a preamp with limited headroom isnt very practical.
Some people like there music loud. If your listening to a few watts power out of your amp a clip like this will hit your speakers with hundreds of watts, probably after clipping your line level amps (volume control?) and/or power amp, which will add even more high freqs (and 10dbv is probably a conservative number, imagine 15dbv or a 1000 times nominal power), a lot of it ending up in the tweeters.
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