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Emubitter

Step up Transformers for LOMC?

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Hi,

 

I am considering upgrading to a LOMC  cartridge... currently running Gyrodec, SME IV, Dynavector 10x4Mk11 HOMC into Transcendent phono stage,  Transcendent Grounded Grid preamp... I am happy with the phono pre but it is only built for MM or HOMC inputs. I think that to run a LOMC I would need to install SUT in front of the phono stage. Is this correct?

 

Could anyone advise brands to consider, prefer australian sources if possible, what sort of budget would I need commensurate with the rig and say, a $1500 ish LOMC cartridge.

 

Any advice most welcome.

 

Thanks,

 

Ken

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You could consider DIY.  I was running a 100uV output MC on my LP12 and used cinemag 1254's that I got from Geoff at Aurealis Audio.  Also, had gain switching using an Elma switch for 10, 20 and 40 x (I was using 40x) and ground lift option switching.  I was really happy with the result.

 

Put it into a nice wooden cheeked enclosure, wooden control knobs with inlayed Paua (abalone) shell.  Bit excessive, but, DIY needs to look good as well in my view.

 

Parts cost about $1,200.  But, with a basic enclosure, feet and knobs and no gain switching could be done around the $800 in parts cost.

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1 hour ago, Emubitter said:

Hi,

 

I am considering upgrading to a LOMC  cartridge... currently running Gyrodec, SME IV, Dynavector 10x4Mk11 HOMC into Transcendent phono stage,  Transcendent Grounded Grid preamp... I am happy with the phono pre but it is only built for MM or HOMC inputs. I think that to run a LOMC I would need to install SUT in front of the phono stage. Is this correct?

 

Could anyone advise brands to consider, prefer australian sources if possible, what sort of budget would I need commensurate with the rig and say, a $1500 ish LOMC cartridge.

 

Any advice most welcome.

 

Thanks,

 

Ken

 

Once you change to a LOMC (from a HOMC which expects to be loaded with the default 47K of an MM phono stage) you are faced with the "cart loading issue".  :)  IOW ... what load will bring out the best in your LOMC cart?

 

If you use a SUT before the MM phono stage, to increase the signal level from your LOMC, then you are limited as regards loading - the load seen by the cart is simply this:

  • 47K MM phono stage input resistance
  • divided by the square of the SUT coil ratio.

So:

  • a 1:10 SUT delivers 47,000 / 10x10  = 470 ohms
  • and a 1:20 SUT delivers 118 ohms.

An alternative is to use an active 'head amp' in place of a SUT; this gives you a highly flexible loading ability!

 

There are several on the market - all of which are less costly than the above DIY SUT solution:

  • G. Slee 'Elevator'
  • Hagerman 'Piccolo2'
  • and Hugh ('Mr AKSA') Dean's "Paris".  Hugh designed this in the early 2000s but is no longer able to build them - so he's handed that task over to me.  :)  Please PM me if you'd like to know more.

 

Regards,

Andy

 

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And a DIY could be a lot cheaper than this.  I used good transformers, quality RCA's and ground post.

 

I certainly am not offering to build one :no:

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4 hours ago, tesla13BMW said:

 

And a DIY could be a lot cheaper than this.  I used good transformers, quality RCA's and ground post.

 

 

It certainly could, Chris.  But you "used good transformers, quality RCAs and ground post, and a high quality gain switch".  Hence the $1200 component price.

 

Sure, the OP could buy the components from eBay - but then he would experience a significantly worse sound than what you've been able to achieve.!  :)

 

If you're interested in the comparison, I could send you up a Paris to run against your SUT.  My belief is that it (the Paris) will sound better ... but then, I'm biased!  :lol:

 

Andy

 

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Hi Ken,

Yes.. with an SUT you can use LOMC into an MM input (in fact - arguably that will sound better than many MC inputs).

 

You will need to match the SUT to the cartridge you intend on using (gain and impedance wise) so choose cartridge first and then look for matching SUT.

 

I am aware of Ortofon producing SUT options for their own cartridges... but I think they are a special order item in Australia.

 

I've heard that the Bob's Devices SUT are custom made and sound great...

https://www.bobsdevices.com

 

If you end up with a Dybavector LOMC you could always look at the P75 phono stage they make as it is well priced, sounds great and matches their own carts very well.

 

Good Luck 👍😀

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Hello Ken,

 

There is something screwy with this thread, because I’m sure I posted here and in a duplicated thread as well.😀 Anyhow, I can recommend the Slee Elevator EXP to you and I have sent you a PM with a bit more detail.

 

Good luck with your search.

 

Cheers,

 

Keith

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Good Morning,

 

I would like to thank all you gentlemen for taking the time to respond so cogently to my enquiry.. clearly I need to understand more fully the role of impedance and loading on LOMC and the interaction with the SUT or head amp that is chosen. i am not in a great hurry therefore I will study the subject a little further,

 

Thanks again,

 

Ken

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4 hours ago, Emubitter said:

Good Morning,

 

I would like to thank all you gentlemen for taking the time to respond so cogently to my enquiry.. clearly I need to understand more fully the role of impedance and loading on LOMC and the interaction with the SUT or head amp that is chosen. i am not in a great hurry therefore I will study the subject a little further,

 

Thanks again,

 

Ken

Or....just get a current amplification phonostage or Classe NIL....life it too short to worry about impedance matching.....  :)

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Interesting you use the word “upgrading”.  Who said a LOMC is an upgrade?  I suspect there are a number of MM carts that’ll blow whatever MC cart you have in mind out of the water.  More expensive, sure.

I’m no expert but I’ve been chasing my tail on sound quality long enough to know I’ve been lead on a merry dance about cart sound quality. 
Here’s one fact about cart output.  Less output means more phono stage amplification required. More amplification at that level means more noise.  You might solve one problem but you cause another. 
Everything in audio, and I mean EVERYTHING, is built on compromise. The best thing you can do is make sure your gear is balanced. 

If you’re happy (as you say) with your phono stage then keep it and choose a cart that plays within its limits. 
I mucked about with all sorts of carts, decks, cables, spent thousands. Then a mate came over, shifted my speakers a bit, put a cot mattress in the first reflection position and made more of an impact to the sound quality than any amount of money I’d spent to date.
Just my humble opinion.

 

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