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?

hollowman

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

 

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.