@larryi
"An older design, and one cheaper than magnetic cartridges is the piezo-electric cartridges where the cantilever pushes against and bends material that emits electrons when bent."
Yes, it was a ceramic element and were commonly used in "record players" and you can still find them in use in Crosley products and other off brand offerings on the lowest end of the vinyl hobby.
In the 70s and 80s a company named Micro Acoustics applied the piezo principal in a more sophisticated designed for audiophile use which used a beryllium cantilever attached to the ceramic element and advanced stylus geometry. The advantages were higher output, compliance and lower cartridge mass. They had a following for a while into the mid 80s or so but higher mass and lower compliance MCs were becoming the norm when the trend moved away from low moving mass and high compliance.
@elliottbnewcombjr
What do you take issue with here? The statements you quoted are salient, technically correct and excepted as standard practice by any authority in the hobby!
"I don’t trust AI, this is what came up this time:
Understanding "Safe Limits"
Nominal Output: Most MM cartridges have a typical output of 3mV to 5mV at a standard recorded velocity of 5 cm/sec. This is the expected signal level the phono input is designed to receive.
Overload Margin (Headroom): This is the critical specification that defines the "safe high limit." It measures how much louder the signal can get than the nominal level before the phono stage introduces audible distortion (clipping). A good phono stage should have an overload margin of at least 20 dB (decibels). This margin accounts for loud passages and peak dynamics in modern recordings, which can be several decibels hotter than average.
Maximum Input Voltage: While not always explicitly stated in user manuals, a 20 dB overload margin above a 5mV nominal input means the phono stage can likely handle peaks up to around 50mV (since 20 dB is a 10x voltage increase). Inputs can typically handle even higher voltages before component damage (usually in the volts range), but audible clipping will occur long before that.
Key Considerations
Matching Components: The primary concern is using a cartridge that is compatible with your phono input’s design. Using a cartridge with a significantly higher output (e.g., some high-output moving coil (HOMC) cartridges can reach 2.5mV to 4mV, which is close to the bottom end of the MM range but can have high peaks) will immediately reduce your effective overload margin, leading to distortion on loud tracks.
Audible Distortion: The most practical indicator of exceeding the "safe high limit" is audible distortion, compression, or a "squashed" sound during loud musical peaks.
Input Impedance: Standard MM inputs have a fixed input resistance of 47 kilohms (kΩ). The input capacitance is also important and typically ranges from 100 pF to 400 pF (picofarads). Matching these to your cartridge’s manufacturer specifications ensures proper frequency response and operation.
In summary, as long as your cartridge’s output is within the standard 3-5mV range and your phono preamp has a decent overload margin (typically >20dB), the input is operating within its safe limits. The danger point is generally not equipment damage, but rather poor sound quality due to signal clipping.
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PASS
Always look for a SUT or MC Phono Stage to have a PASS option, so you can play a higher output MM or HOMC cartridge, bypassing the internal transformer, skipping the pre-boost. This lets you use the same arm/wires/inputs."
