Ortofon MC Diamond and SPU Mono CG 25.

[Yeti]

I Emailed Ortofon about their “true mono” cartridges. They replied to say the only models without vertical compliance are the two CG pickup heads, the rest are safe in a stereo groove but have the coils aligned for mono.
Not all my stereo discs are marked as such, or if I don’t put on glasses and search the cover and label I don’t always spot it so a cartridge that will destroy a stereo disc is out so not a Miyajima mono.
My first stab at a mono cartridge is a London Decca Maroon, which was available wired for mono. The coils are already correctly oriented so it’s just a matter of cancelling the output from the vertical one and there’s a reduced vertical compliance compared to horizontal. There are however some older mono discs that actually sound better played on my SPU Royal N with the mono button, I’m assuming the Decca’s 18? spherical stylus is just a bit too small for hose discs whereas the Replicant 100 is fully engaged, there’s also the possibility that they’ve just worn out with an earlier spherical stylus and the replicant is running on fresh vinyl above any dameage. Whatever the reason I’m inclined to look to a profile more towards the Replicant than the spherical for my next mono cartridge.

options.
There’s the Ortofon MC A mono with a Replicant 100 which looks like the obvious answer but the price has me considering what else would fit the bill but it’s pricy.
Hana have an MC mono with a Shibata.
Ortofon no longer list the 2m mono SE, do the styli from the stereo 2m series work with a mono body?
Wait for London to resume production and go for a fineline version this time. Supergold, Jubilee or Reference (again the price on that last even at the level they were last at).
What else?
Soundsmith seem to offer mono versions of at least some of their cartridges.

 

[mtemur]

What else?

I recommend you to check Miyajima Kotetu. It has 0.4x0.7 mil elliptical stylus. Here is a picture of it from Stereophile article

 

[rl1856]

Regarding mono cartridge choices, I stumbled across a review of a mono converted Denon 103:

VAS Ebony Mono Denon DL-102 103 Shure SC35C Thomas Schick

NY Diary (19-22): 4 Low Compliance Cartridges VAS Ebony 103 Mono Shure SC35C, Part III Denon DL-102, Part IV Thorens TD-124 with Thom...

cheaptubeaudio.blogspot.com

I was intrigued enough to reach out to Steve Leung at VAS. We exchanged a few emails, and I agreed to purchase a standard Denon 103 that is modified for mono use. One coil is removed, and the remaining coil is reoriented to respond to horizontal content. Vertical compliance remains, but a signal is not generated. Stylus is .7mil conical and this is his standard stylus. He may install an elliptical stylus upon request. Recommended loading is standard Denon 103....100 ohms.

This cartridge sounds better than my CG25....to my ears and in my system. Bass is not as robust, but it is still very strong and forceful. Midrange clarity is excellent. HF extension is outstanding in comparison and really affects how the overall cartridge sounds. Along with HF clarity, transient response is much improved. I do not get a single pinpoint image in front of me. Instead I get a large image around the center point and can hear depth and soundstage air. There is a sense of layering but of course, no width. A very enjoyable experience overall.

In direct comparison, the CG25 has stronger bass response but treble/HF is rolled off. I do wonder if the lack of HF extension makes the bass seem more prominent ?

The cost of the VAS mono 103 is about the same as lightly used CG25 from one of the Japanese used equipment sites, or from Ebay.

I would consider this cartridge before spending $3k+ for something else.

 

[Yeti]

I recommend you to check Miyajima Kotetu. It has 0.4x0.7 mil elliptical stylus. Here is a picture of it from Stereophile article

View attachment 111961

But no vertical compliance as far as I can tell from the Miyajima’s “English” website so not safe if it lands in a stereo groove.