2. analog
  3. 143718-105005

Attenuator & Transformer for Moving Coil cartridge

my analog front end is as follows:
- Lyra Delos
-Clearaudio Performance turntable
_ Musical Fidelity XLPS-V3

I am delighted with the sound of this system. Obviously The turntable is connected to the MC connectors of the XLPS.
However, the other night I discovered that I had a SignetMK10T Transformer for Moving Coil cartridges from years ago unused in a box.
I wanted to start playing with transformers feeding into the MM input of my phono stage but then noticed that with the step up ratio of 1-15 of the Signet, given that Delos produces 0.6 mV this will present 9mV to the phono stage which is clearly way too high.

so my basic question is could placing HIFI quality attenuators between the transformer and the phono stage bring the voltage down to an acceptable 5mV level?

Would this have an adverse effect on the sound quality gains of using a transformer ? if not what value of attenuation should be used?

Thanks in advance for all your replies and advice.

mgolpoor
128x128mgolpoor
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mulveling's avatar
mulveling
502 posts
 
15x ratio for a 0.6mV can actually work great, contingent upon the synergy of your cart to a particular SUT. Just try it and see what you’ve got. Pretty sure it stands at least a reasonable chance of beating a solid-state MC stage. Depends of course on the gain structure of your system and overload margins in the MM stage, etc. But don’t assume it can’t sound awesome. 

Ive used 16x and 20x SUTs with 0.5mV and 0.6mV, with superb results.
folkfreak's avatar
folkfreak
1,149 posts
 
I'm not sure a 1:15 would be that much of a problem -- the XLPS-V3 appears to have plenty of overload margin -- provided your preamp is comfortable with the level presented it may work

A more problematic issue may be load matching from cartridge to the step up -- the MK10T has a listed input impedance of 18ohms and the Delos an impedance of 8.2 ohms. Lyra state "recommended load via step up transformer is 5-15 ohms" so the MK10T may work -- there's a lot more discussion on this topic here
http://www.rothwellaudioproducts.co.uk/html/mc_step-up_transformers_explai.html
mgolpoor's avatar
mgolpoor OP
19 posts
 
Thank you guys for your responses. 
After reading all of these I have put aside the idea of of trying to reduce the output of the SUT, as the wrong approach.
I the next day or two I will actually try the Signet SUT with the Delos and will report back of my findings.
lewm
6,770 posts
 
I should have said it myself; try it (the 1:15 SUT with no attenuation of its output).  You can't break anything.  I concur with the others that it might work OK.  Except I don't necessarily agree that a good MC phono stage is never as good as MM + SUT.  But that's not the question here.


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