Suggestion for Valve phonostage to play MONO records only

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Originally Posted by montesquieu

Whatever the mechanics (and the above is a useful observation which would suggest that where the coils are rotated as in the Soundsmith approach, then only one coil is used for output) it's pretty clear that when Ortofon write True Mono in caps and have a special page for all their cartridges, they are obviously NOT talking about simple strapping of a stereo cartridge. Likewise Koetsu who do the same (and who like Ortofon don't have a Miyajima/vintage-like approach with single generator and horizontal only motion), and Lyra who have two mono coils (their approach is documented, Jonathan Carr has several write-ups out there). And Audio Technica whose AT33 monos are true mono as well (I've also owned these in both LP and SP form).

Or do you claim to know more than the engineers behind these illustrious companies? Are they all putting lies out there?

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What is your problem? It is very simply a question of definition -HOW do we define a true mono design and WHAT is a true mono cartridge in 2017 ? When we have got a definition for something then we can evaluate everything and anything by this definition. That's all. And the opening question for discussion in this thread was if a SPU Mono -not Koetsu, Lyra, Miyajima, Soundsmith- is a true mono cartridge or not...? You can't answer it and Ortofon doesn't address this issue either. So why bother...?

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Originally Posted by forsell

What is your problem? It is very simply a question of definition -HOW do we define a true mono design and WHAT is a true mono cartridge in 2017 ? When we have got a definition for something then we can evaluate everything and anything by this definition. That's all. And the opening question for discussion in this thread was if a SPU Mono -not Koetsu, Lyra, Miyajima, Soundsmith- is a true mono cartridge or not...? You can't answer it and Ortofon doesn't address this issue either. So why bother...?

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Knock it off George. The first four words and the last three in your post are unnecessary and not helpful!

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Originally Posted by walpurgis

Knock it off George. The first four words and the last three in your post are unnecessary and not helpful!

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No worries Geoff. Life's too short to bother with trolls, I've finally found out how to add someone to the ignore list, in a decade here I've never felt the need to use it before.

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Originally Posted by montesquieu

No worries Geoff. Life's too short to bother with trolls, I've finally found out how to add someone to the ignore list, in a decade here I've never felt the need to use it before.

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Moderated...
edited out...

forsell, any more from you and your out! (struth)

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Originally Posted by forsell

edited out...

forsell, any more from you and your out!

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Delete my account please. I am too tired and bored of this "elite club" of a handful "senior members" and adms who think that with +2000 posts they automatically acquire a right for insults and offensive behaviour. Cheers and Good Luck.

you were the one handing out the insults. its same rules for everyone.. bye

I've come late to this 'discussion', so my contibution is probably post hoc, but if the question is to whether the Ortofon SPU Mono (or however it is designated) is a true mono cartridge, then the answer is simple: undo the screw holding the belly plate in position and look inside.

Are there only two wires connecting to a single coil arranged to respond to lateral groove motion? If yes, then it is a true mono cartridge.

I can't see why Ortofon would go to the bother of adding a second coil to respond to vertical motion only, because no mono records are cut using vertical modulation. And to replay a stereo record, the coils would have to be connected in a sum and difference arrangement to extract the LH and RH signals.

I probably only have about less than 50 mono LPs, so I'm happy to use a stereo cartridge and the 'mono' switch on my preamp to play them.



There is no need for these discussions to descend into rancour and acrimony.

Just got back to this myself. I cant believe how far off topic this thread has gone. I only wanted suggestions for a mono phonostage, crikey!

Like Rexton, I am also rather befuddled about the goings on. Somehow this thread about true valve mono phono stages has drifted into a bit of "handbags" (as one would call it in rugby) about mono cartridge design.

Forsell is correct in that the original mono cartridge design only included one coil to read lateral modulation on the groove. Many of the modern mono cartridges (not Mijayima) have two coils with the coils rotated 45 degrees, so that the vertical modulation signals cancel out each other (except they don't quite cancel each other out perfectly, according to some). The use of two coils may be a manufacturing cost saving, so that cartridge makers don't have to tool up to make a single coil design for vanishingly small numbers of sales.

Forsell's point is not unreasonable and I'm afraid that I have a bit of sympathy with him. I don't think his posts were particularly abusive - bit forthright perhaps. OK maybe I'll get banned now.

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Originally Posted by topoxforddoc

Like Rexton, I am also rather befuddled about the goings on. Somehow this thread about true valve mono phono stages has drifted into a bit of "handbags" (as one would call it in rugby) about mono cartridge design.

Forsell is correct in that the original mono cartridge design only included one coil to read lateral modulation on the groove. Many of the modern mono cartridges (not Mijayima) have two coils with the coils rotated 45 degrees, so that the vertical modulation signals cancel out each other (except they don't quite cancel each other out perfectly, according to some). The use of two coils may be a manufacturing cost saving, so that cartridge makers don't have to tool up to make a single coil design for vanishingly small numbers of sales.

Forsell's point is not unreasonable and I'm afraid that I have a bit of sympathy with him. I don't think his posts were particularly abusive - bit forthright perhaps. OK maybe I'll get banned now.

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Surprised you look at it that way Charlie. Rexton, the OP, asked for some advice on getting the best out of his SPU GM Mono mkIIi. In post 3 a relatively new member decided to piss on his chips by asserting that the SPU Mono GM was no better than any old stereo cartridge strapped for mono. As someone with more experience than most in getting the best out of mono I thought I would challenge that. My background is not technical (my first degree was in music, I was an organ scholar, and later became a journalist and, post MBA, a management consultant - I'm no engineer and have never claimed to be one) but I have been through a shed load of kit in this area, in my efforts to get the best out of a large collection of early microgroove mono LPs as well as a fair smattering of 78s.

Are you saying Charlie that like a certain poster you agree that the entire range of Ortofon 'true mono' cartridges are no better than any old stereo cartridge with the mono button pressed? Because that's what I was challenging. (On the basis of having owned a few of them as well as other mono cartridges, at one point I even had a dedicated mono system).