Mono Reissues and the Conical Stylus

pryso, thanks for the URL!

chakster, sorry but spell check wants to change your moniker.  I didn't notice in time to correct it.

Can anyone provide a reference to the "U" shaped groove and how it is cut?

dave

Hi Dave, Do you have any thoughts on the putative benefits of a "true mono" cartridge vs a mono cartridge created from a stereo cartridge by bridging the two channels internally?
I think someone originally must have used the upper case "U" to symbolize the shape of an early mono record groove, for want of a letter in the alphabet that better conforms to the actual shape of the groove, whatever that is. Now we all use it without thinking much about it.

I think there is some general confusion about the bridging concept used to sum the stereo signal to add the lateral movement and null the vertical and a cartridge that only picks up information in the lateral plane.    My take is that if the coils remain oriented at a 45º angle to the record and then wired in series for mono then it is a stereo cartridge wired for mono and it doesn't matter if it if done internally or externally.  If however the same parts are used for a mono cartridge and the coil is oriented so there is only pickup in the lateral plane, then it is a mono cartridge.  In this case there would be only be windings for pickup in the lateral plane and the windings at 90º to that plane would not be used / wound.  

As for the "U" shape discussion I think it leads to a bunch of confusion.  I have yet to see a cutting stylus with anything other than a "V" shape with the angle of the v being slightly less than 90º.  Whether this cutting edge cuts with information in just the lateral plane (mono) or in both the lateral and vertical plane (stereo) does not matter and the groove cross section will always be a V.  The only way a groove with a rounded bottom to resemble a "U" could be done would be with a rounded point cutter and I have never seen anything like that and even if it existed, it would do a very poor job of cutting.

dave

Dave, are you saying that late 1940's to late 1950's mono records are cut with the same V shaped groove as stereo records?

That is my understanding.  I just looked at a 1955 London ffrr  (Ted Heath ant the London Palladium) and the groove is a V.  The bottom does have a slight radius.  A stereo cutting stylus specified by Ortophon has a 3-4µm radius which would explain that but that is still a fraction of the radius of even the smallest conical.  

dave

Dave,

I'm thinking that your London LP should be a microgroove pressing. I suppose technically you're correct, that the shape of the groove is a V looking shape however that groove opening is wider than the later stereo cut grooves. In fact, the grooves on LP's started out wider and progressively got more narrow over time. When Columbia introduced their microgroove pressings, manufacturers complained about how narrow the grooves were in comparison to the earlier records (i.e. 78's)
As Lewm mentioned, the U shape description is just a vernacular term for specifying the difference in dimensions in order to clarify the point being made. Mono cartridge makers will use a nude conical stylus because of those earlier groove dimensions.

Dave, You wrote, "My take is that if the coils remain oriented at a 45º angle to the record and then wired in series for mono then it is a stereo cartridge wired for mono and it doesn't matter if it if done internally or externally. If however the same parts are used for a mono cartridge and the coil is oriented so there is only pickup in the lateral plane, then it is a mono cartridge. In this case there would be only be windings for pickup in the lateral plane and the windings at 90º to that plane would not be used / wound."
That is also what I and many others have been saying here and elsewhere.  What I wondered about is whether from a purist standpoint, does the true mono cartridge offer us a level of performance in the mono mode that cannot be had via the bridged stereo approach?  I guess that if you use bridging, then cancellation would be imperfect to the degree that the two channels of the cartridge are not perfectly matched, which probably never happens.

Goofyfoot,
the groove width of the London ffrr is about 2.5 mil which is above the max spec for microgroove. Since the groove is v shaped the width has little to do with whether a conical will properly trace it.   the only issue that can arise is a 1 mil conical can disengage from a microgroove but a 0.7mil conical will not run into any more issues with a 3.2mil groove than it will with a 2.2mil microgroove.  In fact a 0.7 mil playing records previously played with a 1 mil will often be much quieter since it traces a part of the groove that hasn’t been played.  

Just measured a bit closer and the groove with is closer to 3 mil.  I should also clarify that the 2.2 and 3.2 mil numbers I gave are the "average" from the link below and not a hard spec.

https://dgmono.com/2018/04/06/deep-groove-mono-and-the-great-groove-width-mystery/

Dave, here are a couple of sources which explain different styli and groove dimensions as well as other things.

https://www.badenhausen.com/VSR_History.htm

https://dgmono.com/2017/02/17/modern-mono-playback/

I think we're loosing site of what matters, being what stylus type would work well between older mono pressings and newer mono pressings? The reason why I believe this is in need of discussion is because stylus geometry changed with the evolution of the record. I don' think anyone would disagree that the 1 mil. conical stylus, while optimal for early mono records, wasn't ideal for later stereo records. 

I understand that early mono styli track well and sound fine riding higher in the groove than a stereo styli needs to (i.e. pinch effect) however this is not he only reason for considering what differences between styli are important.

Here is a nice article on the subject.  https://dgmono.com/2018/04/06/deep-groove-mono-and-the-great-groove-width-mystery/
It is the stylus radius that is the most important measurement not the shape of the stylus. The smaller stereo stylus might theoretically pick up more noise from trash at the bottom of the groove but if you have clean records what does it matter? Older Mono record from before 1962 and re releases made from the same masters have a slightly wider groove. The shape of the groove is exactly the same 90 degree V with a very small radius at the bottom. 
If you are wealthy and can buy cartridges indiscriminately, wonderful. I am not. I would rather spend my money on one great cartridge than two not so great cartridges. I have quite a few mono records and I never switch cartridges to listen to them. Might they sound better with a conical stylus and a mono specific coil layout. I do not know as I have never been able to make that comparison. I do know that a modern stylus has significantly less mass than a large conical stylus. Consequently all other factors being equal the modern stylus will track better and cause less record wear. 

miijostyn,

thanks for the URL. My nude conical is 0.65 mil and I have no real objections to the richness of sound that I’m getting from 1950’s mono. So maybe a mono cartridge with a Shibata stylus of 0.7 mil or more could be fine; I’m not certain but I do think that the shape of the stylus is also an important consideration, just as the tonearm is.

My parents own.ed a major number of mono recordings from their times living in the states in the 50's. A part is musically so-so, but there are treasures like eg. the Mozart sonata recordings with Walter Gieseking. I always liked the magical sound of these recordings "even" played with my stereo cartridges like Koetsu Black, Monster Genesis 2000 and others. (Turntable were at some time Merrill Heirloom, then WTT Signature and lately a modified Technics SL1210, I used the ET2 arm, where possible). I BTW used these mono recordings to tweak lateral azimuth by minimizimng the"null" mono signal via electrically mono-ed- out-of-phase channels.
After reading several enthusiastic UK reviews of the Miyajima Mono cartridges I started to get intrigued and asked friends, and finally bought a Miyajima Zero and mounted it on a friends Lenco "monster" with Adanalog air bearing arm, where we could "directly" compare a modded (and very good sounding) Denon DL103 vs. the Miyajima on mono recordings.
I was quite smashed by the difference. "Stereo illusions" excepted, I rarely heard as lifelike true timbres and dynamics, and as much colours, and the bass was in a class by itself - in a never heard of way. The "virtual mono" coming from the stereo cartridge somehow simply sounded broken and fluttering, somehow instable.
I truly recommend trying to hear - no, experience this difference for yourself, if you are interested in mono recordings.After listening, some observations and thinking trickled in: Stereo cartridges have to track and electromechanically decode vertical information, mono cartridges do not. For stereo cartridges there is a certain design freedom regarding lateral and vertical compliance, eg. resonance frequency, but in the end vertical resonance will practically never be above 20Hz. The stiffer the suspension, the less the cantilever moves vertically - and that's where almost all extra-musical LF "rubbish" lays.The Miyajimas suspension is much stiffer vertically than laterally, and stiffer than any cartridge I ever saw. And IMO / IME this reduces flutter / Doppler distortion from excess cantilever movement by (almost) an order of magnitude.It reduces this on both a mechanical level and by not decoding it electromagnetically. Which means the coils. cores, and magnetic circuits are much less modulated / saturated by LF, where saturation is at its worst.Internally or externally mono-ing will simply not do the same distortion elimination trick. (It might simply be a marketing decision to sit on a me-mono-too-bandwaggon :-).
Yes, probably cartridge tips will make a difference too...

I don' think anyone would disagree that the 1 mil. conical stylus, while optimal for early mono records, wasn't ideal for later stereo records.

I agree that the 1 mil conical is not a goof choice for micro-groove but I also do not believe it is the best choice for early mono recordings.   I prefer the sound of the micro-ridge compared to anything else for all of the mono I have played with.    The simple fact is that back in the day the 1 mil conical wasn't the "best option" it was the "only option".  Just because more advanced profiles didn't exist in the 50's doesn't mean they engineers and enthusiasts  of the day wouldn't have used them for playback if given the chance.
 
here is a "to scale" image comparing a micro-ridge to a 0.7 mil conical.
http://www.intactaudio.com/forum/files/micro_vs_conical_187.jpg

dave

intactaudio,

have you heard the Miyajima Zero? I personally have not but many will claim that it is one of the best mono sounding cartridges. What mono micro ridge cartridges do you believe to be a good choice. And, are their good micro ridge mono cartridges that are more affordably priced?

I have heard a low hour zero compared to one that had been retipped with a Boron / microridge combo in a direct comparison and I felt that while the retipped cartridge was no longer a Miyajima, the sound was superior.  The most surprising thing I found out about the microridge mono combo was how sensitive it was to SRA.  Getting the SRA correct allowed the music to completely escape the speakers and fill the space between and above them with music.  I have also played a fair bit with a Denon 103 converted to mono by rotating the coil 45º for true lateral pickup.  By rotating the stock stylus along with the coil I could then do a fairly close apples to apples comparison of the original aluminum conical combo to a  boron microridge combo.  Granted that there were two things changed (cantilever material and diamond profile) but the sensitivity to SRA and the huge 3D sound field you could get with the microridge was beguiling and points to the profile as the cause of improvement.

Lew asked me above about my thoughts on the true mono with no vertical pickup  vs. a stereo wired mono with the vertical information summing to 0. The above 103 experiments gave me a bit of insight into this too.  Since I had stereo and "true mono" 103's with the same suspension and boron microridge combination I could series strap the stereo and compare the two methods in a fair way.  Sonically the overall presentation was similar but the lateral mono was more dynamic and had what seemed to be a much lower noise floor.  The immediate place this was heard was in the needle drop.  The lateral cut was nearly silent and the stereo wired mono's needle drop was quieter than stereo but still had a unique amusical quality to it.  This is just a single observation but it does seem to fall in line with the ideas presented in the DG mono link by goofyfoot a few posts up.  I think this distills down to the idea that in a perfect world the sides of a mono groove are 180º out of phase with each other yet noise has no inherent phase relationship to the music.  When picked up with a single lateral coil reading the entire groove, there can be no phase anomalies for the noise but when picked up with a two discrete summed coils there is suddenly no consistent nature in the way noise will be summed which can cause some unique sonic results.

dave

Dave, interesting comparisons! And they align well with what I wrote. The mechanical aspect ie. stiffer vertical suspension seems to me still a very important factor.
Recently Shibata tips resurrected, interestingly at the top of the ladder. I principally assumed tha a vdH / Gyger Type I stylus or a MR stylus were "better than Shibata", that's the way they were introduced in the eighties. Maybe... it was already good vdH marketing - or the re-inroduction of Shibata is? However, from what I read about the new top AT MM cartridges, I somehow trust that the Shibata excel in optimizing the musical detail vs. amusical artefacts ratio.
The resurgence of conical styli, with the original SPU or DL 103 "cult" contains some arguments pro conical styli. Ie. a suggested geometrically much more complex pinching effect / movement of the "sharper" modern styli, including MR or Shibata. This would lead to spurious vertical movement as artefacts (more with these sharper styli than with conical styli), and is a claimed reason for the more relaxed "pro-music" way of musical tracing of these very traditional (and superb) cartridges.
Extending this line of thoughts... could mean that the "real" advantage of these sharper styli would stand out considerably more with a "real" mono cartridge like a Miyajima Zero, because the spurious vertical movements would not be decoded, or far less. And the lack of out-of-phase, vertical stereo signals would eliminate a source of intermodulation on top of these spurious movements.

Wow, some people need a higher dose of Thorazine. I could never hear the difference between styli in the same cartridge. I guess my hearing sucks. If you think you need a mono cartridge it is your money. I certainly do not having just listened to a mono copy of Art Blakey's Jazz Messengers. I am not about to spend money on what is most likely a meaningless improvement in sound quality that I sincerely doubt any of these people can reliably distinguish. Spurious vertical movements? I'm going to jump up and down on my tonearm to see if I can create some spurious vertical movements. I wish my d--- would have some of those movements. Maybe I should plug myself into a phono preamp. Any body try that?

'Maybe I should plug myself into a phono preamp. Any body try that?'
Sounds as if your already convinced but if you wish to, then go ahead.

My main point is: The difference I heard was as clearly audible as any I ever heard. Between a very good stereo and a "real mono" cartridge. It’s the kind of difference every non-audiophile hears, because it’s the difference between kind of fake and real life, it’s about musicality and direct connection to the musicians. I agree with you mijostyn that there is too much talk about micro-differences that are only relevant for audiophiles, which are not really relevant for the musical experience.
The rest of my post might be over the top of (your? others?) head, and / or you don’t like the difference to exist? I could understand that. I did so for quite a long time.
Regarding the conical stylus: The stereo cartridge had a very good line contact stylus, the Miyajima a 1um conical. The line contact to our ears didn’t swamp the electromechanical advantage of the "real mono" cartridge. Although it most probably would improve the latter, as Dave observed.
The review (Hifi News) of the 1um vs. the 0.7um version of the Miyajima hinted at even better sound with the bigger radius on "original" mono recordings. But the 0.7um is probably the safer bet, because it wan't harm any of the newer microgroove cut mono LPs (or mono reissues). I decided for the 1um because of the big stock of old monos in my family.

For as many years as I've been playing LPs I should know this.  But this thread helped me realize that I don't.

Early stereo LPs often contained warnings against playing with a mono cartridge.  Was that due to the larger conical mono stylus tip compared to elliptical stereo tip which might cause damage to the groove?

Or was it an issue with vertical motion of the stylus/cantilever?  I've read that true mono cartridges do not pick up vertical groove information.  I assume that is because of the coil configuration rather than the cantilever not being able to move vertically.  If it is the latter is that the reason it can cause groove damage?

The warning against playing a stereo record with a mono cartridge stems from the fact that the early mono cartridges didn't have or need any vertical compliance.  The lack of vertical movement effectively chews up any vertical modulation found in the 45º cut stereo groove. Some current day manufacture cartridges like the Miyajima's adhere to this while others have coils in the lateral plane with compliance in both the lateral and vertical plane.  The Denon 102 was designed as a mono cartridge with vertical compliance so radio stations could use the same cartridge to play both mono and stereo cuts.

dave

Thanks dave.  I suspected that so appreciate the confirmation.

Someone help me on these questions. I have a new ELAC PP2 phono preamp. It has a Mono switch. Is it a waste to buy a Hana Mono considering that Mono switch feature? The answer to this question will help me decide on a two arm capable TT or an arm with multiple head shells. 

gerrym5,
From my understanding, having a mono switch option is comparative to using a stereo to mono splitter. It is taking a stereo signal, by reading the left and right sides of the groove, via the azimuth tonearm adjustment and then channeling that into mono. Doing this is not a substitute for what a mono cartridge will do. The detail, musicality and quiet background that is characteristic of a mono cartridge will not happen by using a stereo cartridge, even with a splitter or a mono switch. Once you have a mono cartridge installed, then you may find that using the mono switch is preferable but that could go either way.

Googyfoot, Based on all that has gone before in this thread, I am not sure how you arrived at the "understanding" you describe above.  What you wrote may fairly be characterized as your opinion.  In your 3rd sentence, you use the term "mono cartridge" without specifying which type.  I assume you refer to a "true mono" cartridge, best described by Intact Audio, one that cannot read vertical deflections of the cantilever for any of several reasons based on its construction.

My experience is consistent with Intactaudio's above with respect to the retip of the Myajima mono and his experimentation with Denon 103 converted to mono with a MR stylus.

I had Steve Leung at VAS install a Namiki MR stylus on a boron cantilever on a very low hours AT 33 Mono last year and it is a better cartridge than the original. On both modern and vintage mono. 

Would never go back to the conical. IMO it is an audiophile myth that conical is the way to go with vintage mono. 

lewm you’re correct and I didn’t realize that I had forgotten to mention that my cartridge description would apply solely to a true mono cartridge design. The criticisms toward a strapped stereo cartridge would be the same as the comments I had made above concerning a splitter or a mono switch. So yes, I recommend purchasing a mono cartridge built as a true mono design.

Would never go back to the conical. IMO it is an audiophile myth that conical is the way to go with vintage mono

.
I agree 100%.  Just because the conical was the tool of the day to play mono doesn't mean the advanced profiles would have been shunned if they had been in existence.  I actually see them as the correct profile to play back anything since it best mimics the pattern cut by the cutterhead.

dave

As I’ve read, yes, mono records (well, all were mono then) in the 40’s to early 50’s did have a wider bottom groove, but by the mid-50’s the bottom of the groove was cut 1/2 as wide, and my the 60’s even less. Probably the reason why modern mono carts with elliptical stylus still work relatively well. I believe all Soundsmith mono carts are built with elliptical stylus, as are the Ortofon MC Quintet carts and Grado ME+. As examples. Thus, modern mono reissues may sound better with one of those carts, or similar, as I have to assume they are cut similar to modern stereo LP’s.

I have an Ortofon 2M Mono cartridge I use when playing my mono recordings. Most of my mono LP’s were released from the mid-50’s into the 60’s. The 2M Mono has a nude spherical (‘conical’) stylus. Their mono cartridge for 78’s is a standard spherical stylus.

I will say this, my mono LP’s sound much better using my Ortofon 2m Mono vs. my stereo Soundsmith Zephyr, Grado Red (with 8mz stylus), or Goldring 1042. It just sounds more full and ‘complete’. It just sounds ‘right’. So, for my ears, there is a significant difference and improvement in mono playback using a dedicated mono cart designed just for that purpose. I’m fortunate to have an arm with a removable headshell(s), so it makes swapping pretty easy.