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  3. 195419-87151

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
elliottbnewcombjr
6,021 posts
 

lewm,

it's different by a factor of 5, or 3.54, or ....

I don't fully understand the velocity, but I think Yogi's source got the number from the sensitivity spec, not the output spec.

OP's folded model sheet in the box  says 5.5mv output strength

and, that specimen's specific calibrated data says sensitivity 1.1mv

the ADC chart spec I posted above defines various model's output at velocity 5 cm/sec, so using lewm's method (but using 5 rather than 3.54) if you multiply sensitivity/cm 1.1 x 5 you get 5,5mv output strength at 5cm/sec.

for lewm's comparison, that unit's sensitivity 1.1 x 3.54 = 3.89, 

I just checked, found the Shure V15Vxmr output at 5cm/sec is only 3.0 (I would have thought higher)

and the AT440ml is a high 5.0mv, also at 5cm/sec (I would have thought lower)

the vintage AT160ml's with Beryllium cantilevers I just started using a few months ago are 5.0mv

 

secretguy
1,871 posts
 

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.

hollowman's avatar
hollowman OP
41 posts
 

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.  

elliottbnewcombjr
6,021 posts
 

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

 

elliottbnewcombjr
6,021 posts
 

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.

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