Originally Posted by montesquieu
I would agree with this based on a similar recent experience.
As I had an extra tonearm and cartridge kicking around and about 125 pretty decent mono records (both vintage late 50's to mid 60's and modern reissues), I figured that I would take a crack at a mono setup in the past year.
I had two retipped Ortofon MC 20 Supers here, one with a boron cantilever and microridge stylus and the other with a sapphire/microridge combo, which was in use for stereo mounted on a Jelco 750D. So I strapped the boron MC 20 Super for mono and stuck it on an older Sumiko FT3 and started running both arms on my Gyrodec. In the end I also ended up buying two identical tonearm leads for the arms as well, so that was also consistent.
This thread is indicative of the often contentious debate on the whole issue of mono cartridges and the concept of "true mono". I did as much reading as I could before I embarked on the adventure and figured that I would start with a stereo cartridge wired/strapped for mono as many of the most vocal types online insist that a summed stereo cartridge, or a mono switch, or Y connector for that matter, will do electronically exactly what a true mono cartridge does physically.
I was actually very pleased with the results of the strapped MC 20 Super. Even mounted on an inferior tonearm it offered up a significantly superior presentation (simply much more fleshed out and alive) while also reducing surface/groove noise as predicted.
The bug hit me, though, to go "true mono" to see if there was something that I was still missing using the strapped stereo cartridge as the true mono advocates with experience seemed to be equally vociferous about that being the way to go.
Figured I would do it on the cheap at first which would give me the option of going back to the strapped MC 20 Super if it was superior and didn't work out, so I opted for an AT 3/Mono LP for $120 U.S. off Ebay. I had some concerns about it matching up with my phono stage, which is a bit unusual (an Aqvox, which is a current mode phono stage that essentially presents a short circuit to moving coil cartridges with a very low impedance-about 2-3 ohms-at its balanced input), but I looked back on a review of the stage in which another higher output/higher internal impedance MC was used pretty successfully with it so I figured I'd give it a shot and didn't have much to lose.
The AT 3 Mono is an odd cartridge in terms of its output (1.2 mV) and its higher internal impedance of 40 ohms. Frankly, it is a cartridge that will present a lot of problems with a lot of phono stages but, in the end, it does work pretty well here. I probably have a slight excess of gain, maybe 2-4 dB, and the AT 3's bigger brother the AT 33 Mono would probably be a better match to my stage.
If you look at the data sheet for the AT 3 Mono, it has two horizontal voice coils wired in series (according to AT) and can be used connected two pin as a straight mono cartridge in a single speaker setup or with all 4 pins connected and run into a stereo preamp (as I'm doing) and two speaker system. The AT 33 mono, on the other hand, has two independent horizontal coils and can only be used into a stereo preamp and two speaker setup.
As you pointed out up-thread Tom, Jonathan Carr at Lyra is on record as suggesting that for mono playback the orientation of the coils is the critical factor as opposed to the purist view that one must have a single coil. From an Audiogon thread, I will quote him here:
""The key issue for mono playback is not the number of signal coils - but their angular orientation, which determines whether they are sensitive to vertical groove modulations or not. A coil design that does not pick up any vertical modulation in the first place gives better sound than picking up the vertical modulation, then attempting to cancel it out later.
IME, what works best in a normal stereo system, is a cartridge with two mono coils. This eliminates any sensitivity to vertical groove modulations, yet avoids the hum issues that a single-coil cartridge may be prone to."
Going to a true mono single coil with absolutely no vertical compliance was not of interest to me as I wanted to play modern reissues with it as well. Both the AT's, although generating signal only with horizontal movement, have an adapated vertical compliance so modern monos cut on a stereo cutter head can be played safely. Are they true mono? I think they are, although a purist might suggest they are not. I think at that stage we're getting into semantics more than anything else.
And, based on my experience, J Carr is correct.
I've been running the AT 3/Mono for about a week or two now and it is fully broken in at this stage I think. I'm pretty surprised at just how much better it is than the strapped Ortofon (which is a much more expensive and sophisticated cartridge and sounds very good in stereo) which was in turn better at playing mono than its non-strapped (almost exact) counterpart.
Even with a relatively crude bonded conical and basic aluminum pipe cantilever (the AT 33 Mono improves on both these for marginally more money) the AT 3 sounds noticeably fuller/more fleshed out and lifelike while at the same time reducing surface noise even more. A bunch of late 50's, early 60's monos that I had seriously considered trading because of playback noise now play virtually near mint. And sound stunning. If the AT 3 has a weakness, it might be in its high frequency playback and midband detail retreival; frankly I expected it to be weak in those areas compared to the strapped Ortofon and am surprised at just how good it really is. I'm kind of clutching at straws looking for weaknesses when, in reality, it really makes the strapped Ortofon sound quite poor for the most part.
So in the end, I think J Carr has hit the nail on the head with respect to mono playback, and what I'm describing applies to both vintage as well as modern reissues (there's a school of thought online that modern monos cut on a stereo head should be played back with a stereo cartridge but you cannot convince me of this now).
I really think that if one has the resources/capability (ie. second table, 2nd arm, removeable headshell on one arm) and the desire to play mono records that it makes sense to go the extra mile with a mono cartridge as opposed to the mono switch, Y cord or strapped stereo cartridge based on my experience.
An expenditure on something like the Miyajima is not in my future as I really want an all rounder to play modern reissues as well; my initial thought on the AT 3 Mono was to wear it out and if it showed promise to send it off for a retip with a better cantilever and stylus but I am rethinking that based on how good it sounds. I might just step up to the AT 33 Mono in 500-600 hours when it wears out and then retip that one way into the future.
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