ADC moving-iron cartridge has "low" output
I have two identical ADC gold-body XLM-III carts from the late 70s. I purch'd them used, as part of two turntables that were each purchased from different parts of the US. Each cart has a different model of stylus (XLM-III and QLN-2) , and styluses can be interchanged.
The MI series from ADC should output 5.5mV, which I have not measured. However, BOTH these carts are challenged wrt output volume. Not only do I have to crank up the vol. more than 1/3 above other carts, but the sonics are a bit "small" and not "full bodied". It might be due to weakening permanent magnetism -- these are both getting close to 50 yrs old .
The perm. magnet in ADC moving iron series is mounted in the removable stylus, just above the stylus/cantilever assemble.
Not sure what else the low volume may be due to??? These are my my only MI carts in my collection. Anyone know more?
One of my all time favorites. I've had several over the years. Output should be adequate. Interestingly, the "updated" models, while still excellent, were not as good as the original. ADC kept reducing compliance because few tonearms had low enough mass and ended up ruining the cartridges. I still have one. |
One had a missing magnet (purch'd on ebay with Sanyo 'table, $80). Absolutely no sound . I had the other cart so I finally noticed the missing magnet.Seem to be common issue with ADC. Glue decays and magnet falls out. Found some NeoDym at hobby store. Took a while to shape into that of OEM. Not perfect, and I could not create that stock "trench" channel. But it works almost like the orig. Only issues: low output, and worn stylii. Maybe moving-iron expert Peter Ledermann (Soundsmith) could install a new stylus/canti and suspension. |
you buy and replace the stylus yourself lp elliptical for xlm mkiii https://www.lpgear.com/product/ADCSXLMIII.html elliptical for qln-ii https://www.lpgear.com/product/ADCSQLNMKII.html
jico or someone may have a micro linear profile that fits the adc body
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OP, the chart a link to the chart appeared in a discussion that I randomly clicked on. I zoom in or out to get anything showing on my monitor completely for the whole page and zoom more for a enlarged portion and take a screenshot press both: windows key and prt sc key (above backspace key) then open it, crop it, save as a jpeg. name it. I upload pics into a virtual system I created here called ,misc info' https://www.audiogon.com/systems/11519 then I can then copy the image address (pic must be on the web) into a post you can copy image, right click, save to your computer. |
Elliot, you have a point. I chose to use 3.54 cm/sec as a standard because 30 or more years ago, that was the standard stylus velocity for calculating output. But you’re correct that in the last few decades, 5cm/sec has become standard. I chose the older standard because I reasoned that MM cartridges of the same vintage as the ADC would have been rated using that standard. This is a subject about which not much has been written. I agree that yogi’s data, that the output was 1.1mV or thereabouts is probably the sensitivity spec, not corrected for the stylu velocity standard, whether that should be 3.54 or 5cm/sec. If so, the units would be mV/cm/sec. |
