MM, MC, or MI cartridge

Having 134 vintage cartridges and having bought/tried/sold 5 MC carts, there are points not mentioned, and poorly explained in this thread.

MC carts do NOT have the edge in detail or lower moving mass. And while MM and MI carts work identically, there are some major differences; these are not explained in this thread.

I’ve had 2 Dynavectors, an AT and an Ortofon MC. If your previous MM/MI carts were average, then MC wins. But I have more than several really good MI carts, and 2 Micro Acoustics carts that trounce the MCs. And….Low compliance MCs ruin  any mass advantage they might have. They are low compliance because the MC designers can’t overcome the coil wire problems with high compliance suspensions. Rob Peter to pay Paul. Make a stiff suspension to hide the coil wire compliance issues.

Micro Acoustics cartridges give you the best of all worlds; high compliance, very low mass, immunity from loading, very high detail/texture, and flat FR.

MI is a subset of MM. But there is a major difference no one talks about, because most don’t know how MM and MI work. Problem with an MM is that the magnet has a N and a S pole; the magnet has to be long enough to ONLY present 1 magnet pole to the coil poles. A short magnet will present both N and S poles in the coil pole gap, causing distortion from simultaneous - and + voltage swings. This makes for a heavy mass on the cantilever even when using rare earth magnets. 
 

MI cartridges are different from MM in one very important aspect: Mono-pole magnet. Only ONE magnet pole (N or S) is induced into the hollow and very light iron armature. So the vibrating armature in the coil pole gap only has a single magnetic charge. The armature is very effectively an extension of only 1pole of the permanent magnet. This produces a pure music sine wave in the coils; it’s that clean and effortless sound well-made MI carts are known for.

I have several MI carts, and the Micro Acoustics carts that leave the $5,000 Dynavector carts wanting. And the AT and Ortofon MC carts.

@jasonbourne52 

@wolfie62 : a mono pole magnet does not exist! If you could invent one you could qualify for the Nobel Prize for Physics!

LOL!!!

Really? You are EXACTLY the type of person I was referring to! You don’t comprehend how MC/MI/MM cartridges work!

When you induce magnetic flux into a non-magnetic soft iron (Mumetal or other brands), you induce from only 1 permanent magnet pole. The entire armature takes on that one pole’s N or S polarity. It would be physically impossible to have both poles of magnetic flux. The armature is then an *extension* of the one magnetic pole. The armature in the coil pole gap has only 1 pole’s magnetic flux. A true MONOPOLE of magnetic flux! 
 

And BTW, a small, powerful rare earth magnet on a cantilever also has 2 magnetic poles in very close proximity to each other, and to the coil poles. Doesn’t happen in an MI armature!

@mglik 

What about moving iron cartridges??

I have always been interested in the legendary London Decca Reference cart.

I currently use a Lyra Atlas SL. Hard to imagine a $5250 London beats the $13K Lyra.

But the. London reviews all say it produces “scary real”.

Anyone have experience with one?

The only real attraction to the Decca cart is that it is a “tip sensing” cart. Not much to do with it being an MI cart. I wrote about MI carts earlier in this thread^^^^^^.
 

The Decca cart reads the stylus movement from close to the stylus. It has a short vertical cantilever tied with a string; the string is the damper to kill resonance in the short vertical cantilever. Not a user-replaceable stylus. 
 

The 1960 GE VR1000 is another phenomenal MI cartridge that is also tip-sensing. Fact is, it’s the only tip-sensing stereo cartridge with a user-replaceable stylus. It reads the stylus movement at the actual stylus, more than the Decca does. Tip-sensing cartridges have a very unique sound! Not bright, but very dynamic and emphatic. Because it doesn’t read from the opposite end of the cantilever, it loses no energy to the long cantilever or into the suspension; all other cartridges do. Until you hear a true tip-sensing stylus you’ll never hear how much energy, dynamics, and FR energy is lost to the cantilever! It’s amazing to hear the stylus in the groove, AT THE GROOVE, and how much more information there is in the grooves. It’s like having a “dynamics amplifier” in your system. Once you hear a record “from the stylus”, NOT from the other end of a long cantilever (MC, MM, MI all have this problem!) you’ll never want to go back to them.

@rauliruegas 

But I'm talking here of vintage cartridges that if were under today production with today parts used for the top LOMC cartridges will be a true challenge to them.

So far, I’ve not had any MC cartridges beat the ADC 10E MKIV with the boron cantilever and nude MR tip. Extremely short/light cantilever and nude Micro Ridge stylus. Superb tracking at 0.75 grams, extremely low moving mass, the best imaging and detail I’ve yet heard. Tip life @0.75 grams is better than 800 hours.

Dear @wolfie62  : Now I own that ADC in stock condition. I posted a thread of the ADC 26/27 original status where I made tests comparisons against top today LOMC cartridges and overall in my room/system me and the owners of the today LOMC cartridges been in agreement that that Pritchard design is just superb and could outperform any other cartridge.

 

I know that you prefer the 10E MKIV and is ok. I have the 26 with 3-4  replacement stylus and now that you brougth here ADC name I will send to an update with boron cantilever and maybe Shibata stylus shape or VDH and yes with the length cantilever of same dimension than the original aluminum one.

@rauliruegas 

Unfortunately for you, the ADC 25/26/27 carts are no match for the 10E MKIV. The 10E-4 came out after those carts, and just before the XLM. The 10E-4 was a test bed to prove Pritchard’s latest development in coil design and coil poles design. The improvement was used in ALL subsequent designs from the XLM to the Astrion. Your ADC 26 and 27 lacks this key technology. I used the 10E-4 with NOS R-26 and R-25(1) styli. It’s the very best of the very best ADC made! I still have 3 NOS of each styli. The styli for the 25/26/27/10E-4 are identical except the original R-15E was a bonded elliptical, not nude. 
 

But you will never achieve the level of performance with the 25/26/27 cart bodies as the 10E-4, regardless of using a retipped stylus. They all lack the fine level of control of the 10E-4. And the XLM to the Astrion lacks the sound of the 10E-4. So your getting a retip won’t raise the performance to the level of the 10E-4. 
 

I did the retip myself. I bought the boron rod and diamond on-line. I have a fine metallurgical microscope and alignment reticles on one of my eyepieces. But from here on, I’ll use Joseph Long. It was an exercise in patience. I used a worn R-15E stylus and cut the aluminum canti where it enters the armature. Then secured the boron rod inside the aluminum sheath. 

@mglik 

On EBay, there is a GE VR 1000 for about $700. It is interesting since there are several stylus about $30. I am not a fan of setting up a cartridge. And I can’t imagine a 1000 will stand up to my Lyra Atlas SL. Love my Lyra.

Is it worth an experiment?

Yeah, the $30 stylus…..

I learned to rebuild the stylus.I don’t use the iron cantilever. With my stylus, the VR1000 is a totally different cartridge. “Flux Mirror” of my own design. Very light and short cantilever. Still an MI cartridge though.