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How to pick a COMPATIBLE phono cartridge

As follow-up to my recent post titled "Da Benz", I'm trying to better educate myself on how to pick a phono cartridge. There are many to choose from but I don't know which "type(s)" (i.e., output, etc.) will work well with my setup. Not considering price or characteristics at this point, but simply compatibility . Once I know that I can research options to make a selection. Looking through some past forums I see this can get complicated, so I'll provide some info on my setup:

Conrad Johnson EF-1 Phono Stage
    Gain: 40, 46, 52 db
    Phono Overload: 70 mV (40 db gain setting)
    Hum and Noise: 88 db below 10mV input

Conrad Johnson Premier 16LS Pre Amp
    Gain: 25 db
    Maximum input: 15 vrms
    Output impedance: under 700 ohms
    Hum and noise: 96 db below 1.0 mV

Conrad Johnson Premier 12 mono block Amps
    140 watts per channel
    Input Sensitivity: 0.90 volts to full power
    Input Impedance: 100k ohms

SME IV Arm
    Cartridge weight range: 5 - 16 grams
    Weight: 700 grams

And my leading cartridge candidate is the Benz Micro Wood (available in low, medium, and high versions), specs as follows:
    Output voltage: 0.4 (Low) 0.8 (Medium) 2.5 (High)
    Internal ohms: 12 (Low) 24 (Medium) 90 (High)
    Loading Range: >100 (Low) >1000 (Medium) 47k (High) 
    Weight: 9 grams
    Compliance: 15 (Low) 14 (Medium) 14 (High)
    Tracking 1.6 - 1.9 grams

The high output has been suggested. 

However, what cartridge specs should I be looking at for compatibility sake with my equipment and why? I have no idea!!!!   

Thank you to anyone who's willing to take the time to read and respond to a posting like this! :-)

Randy


rbschauman
jls001
17 posts
 
You can use the calculator on this page to see gain needed for a particular output. For example, for 0.8 mV output you need gain of 52 dB.

Details of how they arrive at this value is explained in the page.

However, gain matching is only one aspect. One also needs to match the compliance of the cartridge to the effective mass of arm. 14/15 cu would put the cartridges in mid compliance range. SME IV effective mass as per SME's web page is "10/11" gram which is mid mass, so ought to be a good match for the chosen cartridge.
tablejockey
3,956 posts
 
almarg-

10-4 regarding your point. A great spec to be aware of when pulling the trigger and possibly investing  a chunk of cash.
hdm
1,062 posts
 
KAB calculator that jls001 linked to above is very helpful. Unless you are running a very unusual system (passive pre-amplfier, flea type amplifiers with extreme hi-efficiency speakers, etc.), I think you will find it will give you a very accurate read on the type of gain optimization you need to do with the cartridge/phono stage interface.

It has been pretty much deadly accurate for me using multiple cartridges and phono stages over the years. 

For compliance calculations and cartridge/tonearm matching the calculator at vinylengine will also work well

http://https//www.vinylengine.com/cartridge_resonance_evaluator.php

Your phono preamp has probably close to perfect gain for either the high output or medium output Benz and the compliance numbers are favourable on both with your SME arm which has an effective mass of 10./11. 

Your decision IMO should be based only on whether the medium output Benz will outperform the high output version as the gain numbers from your phono pre are just about perfect for both and your phono pre also has load adjustment/capability that is also favourable to both. And the cartridge(s) would appear to also be a perfect match with your arm. Consider yourself very lucky!

I would definitely avoid the low output version. 


rbschauman OP
138 posts
 
Thanks everyone for the help! The calculators are just great, bookmarked!

One last question: If a system can accommodate both medium and high output versions of a cartridge, why choose medium (i.e., why choose a lower output version)? What do lower output cartridges do better than higher? Thinking that's the case...

Randy
jls001
17 posts
 
From the internal resistance figures and loading recommendations, low and medium outputs look like MC cartridges while high looks like MM. So I guess it's a toss up between MM and MC.
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