Mono Cartridge: Best Practices?

[watchnerd]

So I got my first mono cartridge set up this week, an Audio Technica AT33 Mono. It's not sold in the US for some dumb reason, so I had to have it imported from Germany.

It's a modern "true mono" cartridge (meaning it's stereo LP safe because the cantilever can move vertically, although it won't generate any signal from that, unlike vintage mono carts which aren't stereo safe). The internal wiring looks like this:

Basically, two separate mono coils.

Additionally, my amp has the following settings:

1. Stereo
2. Mono (sum the channels)
3. Left (to both speakers)
4. Right (to both speakers)

I've been playing modern mono reissues of Blue Note jazz and all the settings sound good, but they do sound subtlely different.

Stereo sounds, well, more 'stereo' than 'mono' (how can this be? it's a mono cart?)

Left sounds slightly different from Right (manufacturing tolerances? anti-skate? azimuth? but it's a conical cart....).

So since they all sound subjectively good, but different, which one is the most correct way to listen to a mono record using a mono cart?

 

[sergeauckland]

I'm confused as to why there would be two coils in a mono cartridge. A stereo cartridge has the coils arranged so that movement of the stylus at 45° generates full output, so on a mono record with horizontal movement only, there's output, but there's also unwanted output from any vertical movement due to warps, dirt in the grooves, turntable rumble etc etc.

A true mono cartridge would have only one generator arranged horizontally such that only horizontal stylus movement generates output, and vertical movement doesn't. Of course there's always some 'crosstalk' between horizontal and vertical stylus movements, but the principle applies.

With the AT, it's possible that the coils are arranged horizontally rather than 45/45 and they use two coils for mechanical symmetry, as my understanding of the internal mechanism of the AT33 range of cartridges is that they have a tiny plastic former for the coils above the cantilever in a V formation, much like a MM cartridge, rather than the more common 'cruciform' arrangement that other MCs have.

Notwithstanding the mechanical arrangements, with two coils, there will always be a (small) difference between them due to manufacturing tolerances, and what I would do in your situation is to use whichever of the coils measures (or sounds) better, and switch the amp to Mono (L) or Mono (R) as appropriate. Summing the channels is also a way, as that will average the output of the two coils.

If you want the true mono experience, then just use one loudspeaker! (Floyd Toole doesn't care for dual loudspeaker mono due to the 2kHz cancellation in the phantom image because of the spacing between our ears!)

S.

 

[watchnerd]

With the AT, it's possible that the coils are arranged horizontally rather than 45/45 and they use two coils for mechanical symmetry, as my understanding of the internal mechanism of the AT33 range of cartridges is that they have a tiny plastic former for the coils above the cantilever in a V formation, much like a MM cartridge, rather than the more common 'cruciform' arrangement that other MCs have.

Yes, they are arranged horizontally, and I think mechanical symmetry, plus manufacturing efficiency are the reasons.

Ortofon and Audio Technica, as far as I know, are the only manufacturers to have multiple mono cartridges spanning multiple ranges. Ortofon has at least 4 (2M, Quintet, Cadenza, SPU), likewise for AT (33 Mono, 3 SP, 3 LP, VM). They're all modern mono carts with 4 pins, cartridge bodies that are shared with stereo carts, and vertical compliance so they're stereo safe. No doubt, at the volume AT and Ortofon operate, manufacturing efficiency comes into play, so none of them are ground-up unique designs. And for cartridge swappers using a single tonearm, that's probably a good thing, as the similarity makes it easier to swap with a stereo cart of the same line.

But a more dedicated mono purist, or someone with 2 tonearms, could use a stereo-safe 2 pin mono cart, like the Denon DL-102 and a single channel of amplification.

And a real hardcore type would use one of the rare 2 pin carts with no vertical compliance at all, i.e. not stereo safe.

For me, while I do have enough mono LPs (~100) to justify owning a mono cart, they're still only 25% of my collection, which precludes optimizing solely around mono. Not to mention the times I want to listen to digital.

If you want the true mono experience, then just use one loudspeaker! (Floyd Toole doesn't care for dual loudspeaker mono due to the 2kHz cancellation in the phantom image because of the spacing between our ears!)

Indeed.

But I don't have a center channel, and listening to just one speaker on the right or the left sounds weirder to me than 2 speaker mono....maybe this is just a brain training issue, but my habit (from stereo) is to sit in the middle and expect the musician in the middle, too. It feels odd to have the musician be off to the side.

 

[sergeauckland]

Indeed.

But I don't have a center channel, and listening to just one speaker on the right or the left sounds weirder to me than 2 speaker mono....maybe this is just a brain training issue, but my habit (from stereo) is to sit in the middle and expect the musician in the middle, too. It feels odd to have the musician be off to the side.

Nor do I, I too listen to mono on both loudspeakers with a phantom centre image. My AEG turntable has a peculiarity that when switched to mono, it outputs the left channel only, but that sounds odd, so for the same reasons as you, I prefer dual channel mono. I suppose I've got used to the 2kHz effect, and don't notice it. In fact, I didn't know about it until I read Floyd Toole's book, and tried it for myself. I can't hear it on music, but using noise, it's very noticeable as one moves one's head from side to side by a few centimetres.

S

 

[watchnerd]

Nor do I, I too listen to mono on both loudspeakers with a phantom centre image. My AEG turntable has a peculiarity that when switched to mono, it outputs the left channel only, but that sounds odd, so for the same reasons as you, I prefer dual channel mono. I suppose I've got used to the 2kHz effect, and don't notice it. In fact, I didn't know about it until I read Floyd Toole's book, and tried it for myself. I can't hear it on music, but using noise, it's very noticeable as one moves one's head from side to side by a few centimetres.

S

Does the effect exist if listening through headphones?

 

[Fitzcaraldo215]

Does the effect exist if listening through headphones?

No. It is, when listening to speakers, about the shape and blocking action of your head and ears, which are to the sides. That is mainly all outside the headphones, which are directed straight into the ear canal.

 

[Ceburaska]

Now is clearly the time to out myself as owning a turntable specifically for mono, a Lenco currently with a Miyajima cartridge. I also have the AT33, which is pretty good and, as you mention, won’t kill stereo records. The Miyajima will, so I don’t use it for post 1968 mono records which are likely to have been cut on stereo lathes. I’m just repeating stuff I’ve picked up from the Steve Hoffman forum, so don’t shoot me if this is bollocks!
I’ve got >200 mono records and can’t recommend a mono cart highly enough as they just don’t pick up the same level of noise as a stereo cart.
However the advice from Hoffman is to use a stereo cart on modern mono reissues. Just to muddy the waters!
Just out of interest, do you have detachable headshell or are you running a separate mono deck too?

 

[watchnerd]

Now is clearly the time to out myself as owning a turntable specifically for mono, a Lenco currently with a Miyajima cartridge. I also have the AT33, which is pretty good and, as you mention, won’t kill stereo records. The Miyajima will, so I don’t use it for post 1968 mono records which are likely to have been cut on stereo lathes. I’m just repeating stuff I’ve picked up from the Steve Hoffman forum, so don’t shoot me if this is bollocks!
I’ve got >200 mono records and can’t recommend a mono cart highly enough as they just don’t pick up the same level of noise as a stereo cart.
However the advice from Hoffman is to use a stereo cart on modern mono reissues. Just to muddy the waters!
Just out of interest, do you have detachable headshell or are you running a separate mono deck too?

I have a detachable headshell; my turntable is a Michell Gyro SE, with a Jelco SA-750D tonearm.

But while my Gyro SE is fully upgraded to the modern specs (and beyond with other upgrades), the original chassis (I'm not the original owner) is a MK II model from the early 1980s, which means it has the drill-outs to mount 2nd arm board.

So while I probably can't get a 2nd turntable if I want to keep domestic peace, I could probably get away with a 2nd arm. And my Devialet can be configured for a 2nd phono input, too.

As for using a modern stereo cart on modern reissues....I prefer using a mono cart to using the mono switch.

That being said, I may get a 2nd AT33 Mono and have it retipped with a more advanced stylus shape and cantilever than the conical it comes with, for use with modern mono reissues.

 

[watchnerd]

Now is clearly the time to out myself as owning a turntable specifically for mono, a Lenco currently with a Miyajima cartridge.

Also, congrats on coming out of the vintage LP closet! Be loud and proud!

 

[sergeauckland]

I used to have a Lenco L75 solely for 78s, as the variable speed of the L75 was useful, but that, plus an AEG, EMT and a Garrard 401 all got a bit much, so disposed of the L75 and 401, and have kept the others....albeit added a Connoisseur BD1 as pure nostalgia as that was my first 'proper' turntable. I now use the EMT for 78s, fitted with an Ortofon OM series (stereo) cartridge but with a 78 stylus. For mono LPs, I use either the EMT TSD15 or AT33ML, and just switch the system to mono. 78s are more of a problem, as so few are now playable due to heavy wear. Few people in the 20s, 30s, 40s etc bothered to change the needle for every side, and a worn steel needle and a 200gm+ tracking weight did nothing for record wear. Old records clean up surprisingly well, but wear can't be removed, and the distortion on peaks is pretty unpleasant.

S.

 

[Fitzcaraldo215]

Now is clearly the time to out myself as owning a turntable specifically for mono, a Lenco currently with a Miyajima cartridge. I also have the AT33, which is pretty good and, as you mention, won’t kill stereo records. The Miyajima will, so I don’t use it for post 1968 mono records which are likely to have been cut on stereo lathes. I’m just repeating stuff I’ve picked up from the Steve Hoffman forum, so don’t shoot me if this is bollocks!
I’ve got >200 mono records and can’t recommend a mono cart highly enough as they just don’t pick up the same level of noise as a stereo cart.
However the advice from Hoffman is to use a stereo cart on modern mono reissues. Just to muddy the waters!
Just out of interest, do you have detachable headshell or are you running a separate mono deck too?

I don’t doubt the advantage of a mono cartridge. But, I would be frightened to death about the possibility of accidentally playing a stereo recording with a non-vertically compliant mono cartridge in an unthinking moment. Two dedicated turntables/arms might help. But, even there, I would worry. I have done a lot of stupid things in my life, even when I think hard about the consequences. Put me in a relaxed mood for music listening, and it could easily lead to disaster for a prized stereo LP.

Glad vinyl is only a distant memory, never to return to my system.

 

[watchnerd]

I used to have a Lenco L75 solely for 78s, as the variable speed of the L75 was useful, but that, plus an AEG, EMT and a Garrard 401 all got a bit much, so disposed of the L75 and 401, and have kept the others....albeit added a Connoisseur BD1 as pure nostalgia as that was my first 'proper' turntable. I now use the EMT for 78s, fitted with an Ortofon OM series (stereo) cartridge but with a 78 stylus. For mono LPs, I use either the EMT TSD15 or AT33ML, and just switch the system to mono. 78s are more of a problem, as so few are now playable due to heavy wear. Few people in the 20s, 30s, 40s etc bothered to change the needle for every side, and a worn steel needle and a 200gm+ tracking weight did nothing for record wear. Old records clean up surprisingly well, but wear can't be removed, and the distortion on peaks is pretty unpleasant.

S.

Sadly, I don't think I've ever heard a 78. Only seen them.

 

[Ceburaska]

I don’t doubt the advantage of a mono cartridge. But, I would be frightened to death about the possibility of accidentally playing a stereo recording with a non-vertically compliant mono cartridge in an unthinking moment. Two dedicated turntables/arms might help. But, even there, I would worry. I have done a lot of stupid things in my life, even when I think hard about the consequences. Put me in a relaxed mood for music listening, and it could easily lead to disaster for a prized stereo LP.

Glad vinyl is only a distant memory, never to return to my system.

Well with some simple organisation it is easy...I have colour coded stickers on the plastic sleeves to indicate the records are mono, and which year, so a 1966 mono is two green dots, 1968 three green, 1955 one green. Yes, (endlessly) organising records is all part of the masochistic fun!
Alternatively, go for the AT33 or similar.
Or go digital. I suppose you can spend all the time saved on tagging your classical music collection!

 

[Ceburaska]

I used to have a Lenco L75 solely for 78s, as the variable speed of the L75 was useful, but that, plus an AEG, EMT and a Garrard 401 all got a bit much, so disposed of the L75 and 401, and have kept the others....albeit added a Connoisseur BD1 as pure nostalgia as that was my first 'proper' turntable. I now use the EMT for 78s, fitted with an Ortofon OM series (stereo) cartridge but with a 78 stylus. For mono LPs, I use either the EMT TSD15 or AT33ML, and just switch the system to mono. 78s are more of a problem, as so few are now playable due to heavy wear. Few people in the 20s, 30s, 40s etc bothered to change the needle for every side, and a worn steel needle and a 200gm+ tracking weight did nothing for record wear. Old records clean up surprisingly well, but wear can't be removed, and the distortion on peaks is pretty unpleasant.

S.

I’ve so far resisted 78s as too much palaver even for me.
What is the AEG tt you mention? I don’t think I’ve heard of those before (except for microwave turntables).

 

[sergeauckland]

I’ve so far resisted 78s as too much palaver even for me.
What is the AEG tt you mention? I don’t think I’ve heard of those before (except for microwave turntables).

It's an AEG TRS9000, made to compete with EMT, in the mid 1980s.

 

[watchnerd]

My latest conundrum on mono records:

1953 RIAA curve or 1976 RIAA curve?

So confused...

 

[Wombat]

I’ve so far resisted 78s as too much palaver even for me.
What is the AEG tt you mention? I don’t think I’ve heard of those before (except for microwave turntables).

Here is what you are missing out on: 78s & cylinder recordings

From this free web music streaming and download archive archive: https://archive.org/details/audio

 

[Wombat]

My latest conundrum on mono records:

1953 RIAA curve or 1976 RIAA curve?

So confused...

The 1976 curve(IEC RIAA) introduces an additional filter(cut-off) at 20Hz which also adds amplitude, and even more undesirable, phase errors. It is not considered to be desirable for more aware users.

See in this article: https://en.wikipedia.org/wiki/RIAA_equalization

Earlier than 1953 is mind-boggling: https://wiki.audacityteam.org/wiki/78rpm_playback_curves#78_rpm_EQ_Curve_Generator

Is this helpful?

 

[Soniclife]

My latest conundrum on mono records:

1953 RIAA curve or 1976 RIAA curve?

So confused...

There is a graph somewhere on the net of all the curves the Devialet does, that might help you decide.
Frankly I'd choose whatever sounds best to you, and ignore the science, unless you have vintage mono test records you trust.

 

[Wombat]

If you don't have a Devialet, Audacity will do it for free. https://wiki.audacityteam.org/wiki/EQCurvesDownload