Mono Cartridge Question

Isn’t that just the truth - we need some vertical compliance in case a stereo disk ends up under the wrong tonearm, but we don’t want any signal resulting from the vertical compliance to be fed up the chain.

Peter Ledermann did sort out something for me (honestly, he was very informative and able to answer some questions for me in ways that make sense, even if I strongly disagree with his opinions about Deccas). The issue of "true mono" pickups having dual coils: I assumed they were exactly like a stereo version, but the coils would be wired so as to send the combined output to both channels. Quite wrong, said he, and he should know. All the same components as a stereo version can be used, but the cantilever/magnets are mounted 45° away from the stereo version. Now it becomes possible to take the signal from the coil/magnet sensing horizontal movement and send it to both output pins. The other coil/magnet pair, that now senses vertical movement isn’t even connected. It shouldn’t even be there, but it is cheaper to make one cantilever with two coils on it, and presumably then mount the cantilever/magnets in the appropriate orientation for mono or stereo as desired.

This quiets my fears about pickups like an AT33 Mono or the Ortofon Cadenza Mono (both of which claim "true mono" status), which announce that they have dual coils etc. I’ll wait a week and see if either londondecca.com or Brian at Presence Audio give me a result. If not, I’ll have to choose between the AT and the Cadenza. The Ortofon is three times the price, but I do love it’s great uncle, the Kontrapunkt C. A Miyajima Zero would be twice the price of the Cadenza Mono, and I can’t justify that. I still think a mono conversion of the Jubilee should be child’s play for a tech used to Deccas, and would likely be better than any of the others. But, "You can’t always get what you want" etc...

Questions remain. VAS offer mono conversion of stereo cartridges. Do they just rewire them ("untrue mono"?) or do they rotate the innards such that one coil/magnet reads only lateral movement? I don’t know, but I wish these things were made plain for prospective customers. P. Ledermann says it isn’t worthwhile in terms of price to try to convert any of his pickups to mono, and one should buy one built as mono.

I can't answer all of the questions raised here, but I can add some light at least.  First let me describe my mono vs. stereo cartridges a bit further.  I have a VAS Mono MC, .07 mil elliptical diamond on aluminum cantilever and the brother in stereo.   Next an Ortofon 2M Black and 2M Mono SE, MM, both Shibata on aluminum cantilevers.  Audio Technica AT33 Mono (2), one is 0.07 mil and one is 1.0 mil.   Here is what I have learned.  Use 0.07 mil styli on modern records, reissues etc., but not on old monos as they sound awful.  Conversely, the 1.0 mil stylus doesn't track on modern records.  So if you have a mix of old and new mono records you will need one stylus of each size.  That is where moving magnet cartridges with user replaceable stylii can be handy.  As I have already said a mono cartridge sounds best on a mono record.  But of course the better the cartridge the better the sound.

Next, If you have a record that you are not sure is mono or stereo, start by playing it with a stereo cartridge.  If the record is mono, the image will be centered between the two speakers.  Switching to a mono cartridge will generally make the record quieter and more lively.  For records that were "rechanneled for stereo" or some such nonsense, that means they are full of reverb and generally sound better if played with a mono cartridge.

The problem is: Define "old mono" vs "new mono".  Definition to be used in deciding whether to use the 0.7mil stylus vs a 1.0mil stylus.  I have read many different opinions on that score, and it may vary by label as well as year of manufacture.

Hi Lewm,

Definitions can get tricky.  What I do is clean it and then play the damn record.  If not sure, I play the record with a stereo cartridge first.  That is always going to determine if it is mono or stereo.  Next, I try a 0.07 mil mono.  If it is really noisy, then I try a 1.0 mil mono.  Usually that process works.  If none of those works, the record is donated to a local charity that sells used records.  But that is very rare. 

My policy is if the performance is old enough to have been recorded in mono, and if neither the jacket nor the label proclaim it’s stereo, then I flip the mono switch. But that doesn’t answer my own question. However as a result I’m playing all mono LPs with modern stereo styli, and I don’t notice any problem related to groove width. It may be that I own very few mono LPs that are old enough to require 1.0mil.