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Accession Duo

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Drewan77 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Drewan77 Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jul 2017 at 8:57pm
Graham, the main reasons I do not use MC are clumsiness (I have snagged a couple of cantilevers over the years & am likely to become more cack handed as I get even older) and with fixed headshell Rega based arms, I like the ability to swap styli about.

The IQ3/Accession & AT 150ANA or 2M Black /Reflex M give me as good as I think I can get with MM therefore I have no burning desire to change anything.
Older than I once was, younger than I'll be
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Andrew
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Eric Quote  Post ReplyReply Direct Link To This Post Posted: 12 Jul 2017 at 6:43am
I use MC cartridges, but so far I haven't listening to any MC phono preamp that sounds better then an SUT together with an MM phono preamp.
But so far I haven't not tested any phono preamp from GSP. Embarrassed
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 12 Jul 2017 at 8:41am
The Cantus arm would make it difficult for you to use an all-electronic phono stage, because of its exposed wiring.

All kinds of interference would actually be being conducted by the cartridge wires which have zero protection, and will not be very much lower in amplitude than the cartridge signal - if not for the fact you are using an MC cartridge.

The SUT effectively helps by filtering out the high frequency content, and the moving coil catridge provides a low source inductance effectively making a shorted path for some radio frequencies. But that does not mean it will be clean. There will be frequencies which the cartridge inductance will tune, but these should be of sufficiently high frequency such that the SUT may not pass them.

The use of a MM cartridge into a transistor phono stage would afford lots of radio frequencies the opportunity of creating mayhem. As Keith Armstrong of Cherry Clough EMC Consultants told me:

"... in-band intermodulation products are inevitable when there are two or more frequencies (which there always are) and any non-linearities (which there always are).

"Interestingly, noise with fundamental frequencies that are outside the audio range ... can intermodulate with audio harmonic distortion products that are above the audio range, causing in-band noises to arise.

"The thing with intermodulation 'artefacts' is that they are completely alien to the original waveforms, so even small amounts may sound objectionable even though similar amounts of harmonic distortion products might sound acceptably low.

You could try an Elevator EXP with an Accession M or Reflex M, but there is the possibility that the interference would be of a level to break through and become audible because of the BJT inputs of the EXP.

The Accession MC being JFET will be more immune, but the last paragraph from Keith Armstrong would still apply.

Because of the "dictator style" hypocrisy of the EU, its legislation allows some to get away scot-free, whilst others must deal with their consequences. This is illustrated by the above where the arm manufacturer is under non of the obligations that the electronics designer (me) is under.

Still, I do my best (it's a case of having to).

That none should be able to buy or sell without a smartphone and the knowledge in how to use apps
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Eric Quote  Post ReplyReply Direct Link To This Post Posted: 12 Jul 2017 at 8:57am
Thanks for the lesson/information Graham.
It would have been interesting to hear/read an discussion between you and the designer of the Cantus arm, Bo Hansson who also made amps and speakers, but he passed away some years ago.

My plan is to test the Elevator EXP with Accession M and Reflex M. If it not will work out the next step will be to test the Accession MC.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote morris_minor Quote  Post ReplyReply Direct Link To This Post Posted: 12 Jul 2017 at 10:14am
The marketplace is full of phono amps offering MM/MC switching. The demand must be there. The problem Graham has is that he's too principled to just build one circuit with variable gain for a quick buck, having proven that MCs need treating differently to MMs and thus upping the complexity.

I'm guessing it would be possible to produce a Duo with the Accession amplification(s) but without the EQ switch or double output to make it more like the competition. This may be a slightly cheaper option, but at the kind of level I imagine - £2,500-£3,000?? - you'd want a fully featured unit. Even this kind of price is "cheap" in comparison to a lot of its potential competitors, though.

I'm sitting here with two turntables next to me, one MC, one MM, and with a USB audio interface sitting on my desk with one input. So a Duo is right up my street. Worldwide I can't be that unusual. (No sniggering at the back . . . LOL) The problem - as always - is reaching the potential customers, and taking the risk of development costs.
Bob

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Accession MC/Enigma, Accession MM, Reflex M, Elevator EXP, Era Gold V
Solo ULDE, Novo, Lautus USB and digital, Libran balanced, CuSat50
2 x Proprius + Spatia/Spatia Links
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Post Options Post Options   Thanks (0) Thanks(0)   Quote shashirao Quote  Post ReplyReply Direct Link To This Post Posted: 17 Jul 2017 at 11:08pm
A quick layman question:

I have always used MC carts...and currently have a fabulous experience with the Accession/Elevator combo.

Should I expect better sound with the Accession MC? Or would I be better off with an MM cart and drop the Elevator?

Cheers
Shashi
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Aussie Mick Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jul 2017 at 1:46am
Probably a question for Graham, but on the face of it, dropping an extra box and set of cables should mean the Accession MC gives a better result than MM+Elevator. A purpose designed MC stage should have advantages, otherwise why design one? On the other hand, if starting from scratch a MC stage makes sense if you know you want to go that way. Cheaper and fewer boxes.
Quite a few people here love their high output MC carts and also the Ortofon 2M Black and Bronze on the MM side. So many options!
Good luck!
Rega RP8 - Apheta 2 - Accession MC Enigma PS -Solo ULDE (Focal Utopia) - PS Audio M700 - Fical Kanta No2
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