MONO cartridges

Plinko,
Thats what I have read that the Lyra does not read any vertical info. I think in MF review they talk about cancel as it cannot be read. I would have to read the review again to be sure.

Here is the info on the Lyra that I have.

Specifications:
Type: Moving Coil, low-impedance, low-output, medium compliance
Output voltage: (using CBS STR-100 standard @ 5.0cm/sec) 0.25mV
Frequency Response: 10Hz-50kHz
Channel Separation @ 1kHz: N/A
Diamond Stylus: 3x70 um Ogura PA line contact
Magnet(s): Dual disk neodymium
Square Bobbin: 5N iron core & 6N copper coils
Cantileaver: 0.3mm diameter solid boron circular rod
Recommended tracking force: 1.6-1.75 grams
Dynamic compliance @100Hz: 12x10-6cm/dyn
Internal impedance: 3 ohms
Recommended load impedance Preamp direct: 100ohms-47kohms
Via MC transformer: 2-10ohms
Weight: 8.3g
Other features:
• Machined aluminum alloy, mono-block (nude) construction
• Cantilever mounting
• Direct-Flux, dual disk magnet system
• Full Protective, transparent cover

Pryso: it is the first case and the stereo cartridge is JanAllaerts MC2 Finish.
Jean.

"Narrow profile stylus" isn't an accurate term to describe the stylus used on the Helikon Mono, as it isn't intended to be narrow. On the contrary, it is intended to "fill up" the LP groove as completely as possible without triggering difficulties in setup. "Long contact patch" is a much better way to describe it.

IMO, a proper mono cartridge shouldn't pick up vertical information. A mono cartridge can be approximated by summing the coil outputs of a stereo cartridge together, but this is no better than using a mono switch, and the completeness of cancellation will be limited by any dissimilarities between channels (encompassing those caused by setup as well as build).

The stylus on the Helikon Mono isn't an Ogura PA, as the scanning dimensions of a PA are 3x30um, which is considerably narrower than what is actually used.

The prototypes of the Helikon Mono started out with a 3x30 PA, as that was the same as what was used on the Helikon stereo version at the time. We extensively tested a variety of stylus shapes on both new mono and older mono LPs (some of these dating back to at least 1953~54), and found that a custom variable-radius 3x70um profile was the most to our liking - on everything. And that is what was incorporated into the production version.

Later we found that the custom 3x70um stylus gave better results on stereo LPs as well, so we gradually shifted from the 3x30um Ogura PA to the new 3x70um stylus for all of our cartridges, stereo as well as mono.

The only exception is the entry-level Dorian, which uses a Namiki Microridge 2.5x75um for both the Dorian stereo version and Dorian Mono. I chose Microridge for the Dorian because it was the closest production stylus (meaning less expensive) to the custom 3x70 stylus used on our more expensive models.

FWIW, I don't believe that groove width means much for a wide, long-footprint line contact stylus. The important factors are groove angle and groove depth. The groove angle of a Microgroove LP should be 90 degrees, and as long as it remains 90 degrees, the stylus will simply keep its natural distance (as defined by the stylus shape) from the groove bottom, and should have no problem with remaining in full contact with the groove walls or tracking, regardless of groove width. If the groove bottom is shallow, however, or filled with dirt (not an uncommon condition with second-hand mono records), the tip of the stylus may "bottom out" if it is too acute and goes too deep.

Bottoming out was one of the primary reasons why we rejected the Ogura PA. Our custom 3x70um stylus retains a longer contact patch with the groove wall than the 3x30um Ogura PA (which is the essential thing for performance), but doesn't go quite so deep and therefore doesn't get into problems with shallower grooves.

hth, jonathan carr

I recently purchased a Lyra Helikon mono to play the many mono records in my lp collection. First record after break in
was excellent condition original Blue Note records "Art Blakley and the Jazz Messengers Vol. 2". Stunning presentation and detail even compared to my Airtight PC-l stereo cartridge. Several other Blue Notes produced similar results.
My phono pre is a balanced Einstein "The Turntables Choice".
I tried a Shelter 501 Mk 2 mono which has a single coil, but it's single coil design caused a low volume ground hum which is sometimes the result of using a modern phono pre with a single coil mono cartridge. Since the hum was pretty low, I was still able to ascertain that the Lyra presentation was clearer,larger,and more detailed and alive than the Shelter. Of course it's double the price too.
Got the same hum with my Einstein single ended phono pre
and my AHT Non-Signature phono pre [same design as the Walker phono pre without all the added tweaks,etc]
Be careful if you opt for a single coil pickup at the lower price point that it does not hum with your phono pre.

I have a question as to the best loading for the Helikon.
It's specs say 100ohms to 47k ohms. My Einstein has loading resisters of 40,85,100,150,300, and 940 ohms.
Is this cartridge load sensitive in anyone's experience?
What loading are the other owners using and the results?
None of the reviews of this cartridge comment on loading differences. The instructions talk about the potential difference, but I cannot clearly hear one in a quick initial comparison, but I didin't try very hard. Just wanted to sit and listen to the beautiful music I was finally hearing from those records. Waited a long time for this moment, so testing will have to wait. Thanks for any input.
I have mounted it on a Dynavector 507 Mk 2 arm on my TW Accoustic Raven one TT.