2. analog
  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

Showing 4 responses by lewm

lewm
13,787 posts
 

It’s not “different”, it’s just another way of stating output, in this case with respect to stylus velocity. In those days the standard stylus velocity was 3.54 cm/sec. If you multiply that velocity by 0.9, you get around 3.2 mV, which is a bit less than the typical output of an MM and might account for the OP observation. Or it might not.

lewm
13,787 posts
 

What yogi said rings a bell. When OP said the XLM has output 5.5 mV, that sounded incorrect based only on my fading memory. So I looked it up and also found 5.5mV at the LP Gear website. Memory says its output is less than that of a typical MM. And I owned several back in the day. I totally agree also that ADC quality control was nonexistent. That is one reason I asked the OP what cartridges he was using as comparator. I’d expect a high output MI to have slightly less output than a typical MM.

lewm
13,787 posts
 

No. Insufficient information leads to wild speculation.

What phono stage are you using? What is phono gain? What linestage, amp, speakers? What cartridges are you comparing to the ADCs?

lewm
13,787 posts
 

You have two very old cartridges with unknown provenance. Plus you give no information about your audio system, especially your phono stage.  So there are many possible causes among which it is impossible to distinguish without more data, and even then it may be a crapshoot.

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