MONO cartridge recommendation

My mono cartridges are Lyra Dorian Mono, Audio Technica AT33 mono and Shelter 501 mono. My understanding is that these are "true mono" cartridges in that they only respond to horizontal stylus movement, although the styluses are still vertically compliant. The Shelter is a single coil while the Lyra and AT33 are dual coil, which should reduce the tendency to hum.

I previously owned an Ortofon Quintet mono, which I believe is a strapped stereo cartridge (similarly to the other Ortofon cartridges), although Ortofon do describe all of their cartridges as "true mono".

From information I have gained reading various forums over the years (particularly from Steve Hoffman), it appears that:

- After 1968 most mono issues were pressed from stereo cutting heads and it is virtually certain that this is true for most recent mono reissues (such as the Beatles LPs)
- Using a mono cartridge on LPs cut from stereo cutting heads will generally sound worse than using a stereo cartridge, since there will be some loss of high frequency information. If you have a mono switch (or a Y-cable arrangement) you can tell when an LP was cut from a stereo cutting head since engaging the switch (or Y cable) will result in some loss of HF. If there is no difference, you can use a mono cartridge and there will be the usual benefits of lower noise and wider soundstage.
- The benefits of a mono cartridge will only be heard with pre-1968 mono records, and this will depend also to some extent on the stylus dimensions and the equalisation curve used.

For these reasons I only use my mono carts on older LPs that I know were cut on mono equipment - pre-60s and earlier. For recent mono reissues I use a stereo cartridge.

If I have got any of the above wrong, please feel free to correct me.

folkfreak, I am a little embarrassed to say that I have hardly listened to the Martzy set, even though it is the most expensive LP set I own! I haven't done a serious mono/stereo comparison, so I will make some time this afternoon to do that, with the Shelter 501 mono against the Etna SL.

lewm, as I mentioned, the information I provided was based on reading from a number of forums over the years. There are quite a number of discussions of mono recordings on the Steve Hoffman forums (as there are here) and Steve (who is probably as knowledgeable as anyone on this subject) has made some comments from which I have derived most of this information, so I suggest you do a search of that forum.

folkfreak, thanks for those links. I wasn't aware that ERC used a mono cutter, nor was I aware that Coup d'archet use a stereo cutter, even though I own the Johanna Martzy set from Coup d'archet that is the subject of the review. It therefore makes sense to listen to this reissue with a stereo cartridge.

It's interesting that although discussions of mono cartridges and mono recordings come up frequently, they almost inevitably lead to more confusion than clarity. I don't claim to be an expert, so if anyone has any better information, I for one would certainly appreciate it. 

Actually, it would make more sense to compare the LPs using a Shelter 501 mono vs a Shelter 501 Stereo with the same phono stage. The only variable then would be mono vs stereo version of the same cartridge. Fortunately, I have both versions of the Shelter 501 and my EAR 912 preamp has two phono  inputs. But that comparison will unfortunately have to wait until my new arm arrives in a few weeks.

I've just listened to the Martzy LP of the Mendelssohn concerto with Kletzki on Coup d'archet. First, the Etna SL (with and without mono switch engaged), then the Shelter 501 mono, then back to the Etna SL.

It wasn't even close. The stereo Etna SL has more extended highs, a more natural tone and a very sweet tonal balance. The Shelter 501 mono sounded flatter, duller and just less engaging. As a new LP, surface noise was not a factor.

The mono switch on my preamp hinted at the result, since engaging it with the Etna SL immediately removed some high frequency information and dulled the sound slightly, so the result from the mono cartridge was not really a surprise.

Of course, the Etna SL is a much better cartridge than the Shelter 501, and it is on the better of my two turntables and arms. Even allowing for this, the result was pretty clear.

Soon I will be able mount both the stereo and mono versions of the Shelter 501 on similar arms on the same turntable, and that will be a more interesting comparison. But I suspect I know what the outcome will be, at least with this particular record.