MC and Cambridge 640p

[robsanderson]

I need to buy a new cart as my current v15 III is unsuited to my new TT/arm combo, but am aware that the CA640p is a limiting factor to betaken into account especially as better MC's seem to need varying loading and the CA doesn't feature this.

My thoughts/choices considered to far is to buy a rondo red (seen one new for £315) and either modify the CA or replace it. The ortofon has a low output so the cambridge might struggle with it?

Second option is to blow the bank and buy a Lyra Dorian (£600), Lyra's are considered a great match for my NAS arm (on ace space). The Dorian has a high 0.6mV output will this work better with the CA or worse? I like the idea of the Lyra's micro ridge over the ortofon's elyptical.

A third option is to stick with MM with something like the 2M Black?

The 640p will likely get replaced before too long anyway

[coolmaster]

Allow me to suggest looking into some MC step up transformers and paring it to your 640P, if you're going the MC cartridge route. You may be amazed at the potential.

[markcass]

Hi

The step-up transformer route is certainly one to consider. My Rothwell Audio SUT made a big improvement over the MC input of my Musical Fidelity X-LPS v3.

However, I have used a 640P, and the MC input had no problem dealing with the output of an Ortofon MC25FL, which is about the same as the Rondo Red. I much preferred the Rondo's sound, by the way! I haven't really found the lack of variable loading much of a limitation with this cartridge.

The Cambridge has its limitations, especially with MC cartridges, but there's a huge thread here on modifying it, as you know. Its noise performance is very good in standard form, by the way. I think, though, that it would severely limit the potential of something like the Dorian.

HTH

Mark

[robsanderson]

Thanks Coolmaster and Mark for your help.

One question I have is about the earth on the 640p, how does it work when there is no earth connected to the unit just live/neg from the wallwart? Would I be better earthing the arm and TT chassis to the earth pin of a mains plug?

[coolmaster]

Is there any hum? if all silent without signal, no remedy required.
The tonearm earth could be tied to the negative of the tonearm plug and negating any hum, like how a Rega tonearm is wired.
I did come across a mod with a change of one resistor value in 640P circuitry to increase the gain, IIRC, was in the MM stage. Simple mod and possibly beneficial who need extra gain and more oomph.

[Trackside]

Mains 'earth' and TT 'ground' are different concepts. The TT ground does not need to go any further than the phono stage

[robsanderson]

I'm stuck with the 640p for the time being so need something that will work with this for at least 6 months. The SUT suggestion is something new for me to consider I didn't know what they were! Its something I would still use with future but prices vary from £280 to thousands.

£450 is about my limit right now. I can get a rondo red for £315, a 2m black for £460 or a used (claimed 100hrs) dorian for £450 (returnable if not satisfied). I'm tempted by the rondo red at such a competitive price but would I regret not spending the extra £135 for the superior cart? And am I missing the obvious and should pick 2m black which many people rate above similar priced MC's.

This will bring me to the end of my available funds, so what I don't want to do is buy a cart and it not work well with what I have now ie the 640. I could add an SUT (Rothwell is £280) or upgrade the phono stage in 6 months to a year.

[St.Dunstan]

markcass wrote: "he Cambridge has its limitations, especially with MC cartridges, but there's a huge thread here".

Very interesting. Please, give us some link to that "huge" thread, about "640P" DIY "mods".

[robsanderson]

Please, give us some link to that "huge" thread, about "640P" DIY "mods".

viewtopic.php?t=9098&postdays=0&postorder=asc&start=0

[St.Dunstan]

robsanderson - thank you - nice topic. I like mods with some submarine-like batteries - it's always fun !

[robsanderson]

I bought a low end cart (Audio Technica 110E) to put on my rega so I could sell it as working package and tested the cart out on the spacedeck.

The 110E is a very different presentation to the v15 III with original shure VN35HE stylus and surprisingly good. It sounds a bit clumsy by comparison, it loses the air/soundstage/detail of the v15 but it does bring a nice warmth and tuneful base to the table. I suspect the weak areas of the v15 are down to the missmatch with my arm. The AT100E is better suited compliance wise and that seems to be helping?

I'm excited at the prospect of something with the strengths of both and the magic that synergy can bring. Do I need to go MC? What will it bring that a good MM like the 2m black wont deliver?

I would really appreciate any advice on this, thanks in advance

[youngdand]

I vote the lyra, my lydian, is / was a fantastic sounding cart, untill i pulled the cantilever off it! but it will get re tipped, i have also owned a V15, and the difference between them is vast. The lyra is very exact, everything is there and has a very distict place, and the soundstage is massive. It also is very quiet, and forgiving of older not so loved records.

The V15 was very warm, with load of bass slam, but a little false, although very musical. The lyra retain the musicality, but sucks up detail like a huricane, i have a few samples uploaded to soundcloud of the lyra which i will post below.
Worth the extra few quid, and will last you an upgrade or 2 on the phono stage.

http://soundcloud.com/dan-young-7/your-warm-tender-love
http://soundcloud.com/dan-young-7/jun-fukamachi-snippet
http://soundcloud.com/dan-young-7/pink-floyd-money-snippet

[v1nn1e]

Just to confuse further...

I have an Ortofon 530 which was excellent but a bit old now. I will be getting the 540 stylus for it in due course, which is comparable to the current 2M Black. It is an excellent cart - I don't think you'd be disappointed if you got that and stuck with your 640P.

If you do go MC though, I would strongly recommend a SUT but perhaps more than with a lot of hi-fi, price is proportional to the quality (of the transformers).

[robsanderson]

Thanks for your input youngdand and v1nn1e.

To add to the confusion I notice that the sumiko blackbird HOMC is in the same price bracket and would work with the MM stage of the 640p. I'm a bit wary of HOMC's though, doesn't it compromise some of the the benefits of MC designs?

I can see a new phono stage or SUT being on my christmas list so happy to live with MM, LOMC or HOMC for 6 months, it will give me time to get to know the new cart and better appreciate the improvement of a new phono/SUT when it arrives.