how does the BMC compare to the 3160 phono stage ?
Cartridge Loading.....Part II
I read last night the below noted discussion with great interest. It's a long post but worth the effort and I found it interesting.
It started me thinking about the amount of loading on my moving coil cartridges. Years ago I purchased my first MC Cart, a very nice Benz Micro Glider, medium output of 0.5 mV as I recall. At that time I inquired about loading here on Audiogon. I was convinced, via discussion, by another member, that 300 Ohms was the magic number, so I thought.
Time moved onward and my second MC Cart is currently a Lyra Delos, again medium output 0.6mV. Both carts had Boron cantilevers', 6 nines oxygen free copper coils and line contact diamond stylis. When I set up the Delos I did not change or even consider 'loading' changes. That was a grand mistake.....
Well, thanks to this specific thread I started to second guess myself . (you can do this when retired and more time is on your hands....)
My take from this recent thread is as follows. Load at 100 Ohms or at 47K Ohms with a quality MC cartridge. I opened up my Conrad Johnson EF1 Phono Stage this afternoon. Found it set at 500 Ohms loading. 100 Ohms is not an available setting. Damn...All these years I've been running the wrong loading, and on two carts, back to back... I don't recall why I set the loading at 500 Ohms. Faulty logic.
I reset the loading to 47K, buttoned things up and called the wife in for a listening session. Sure as heck both of us noticed the highs were crisper and more 'apparent' than in the recent past. Not a huge difference, but yes, a difference.. Hard lesson learned!
So, you smarter folks on this site might banter amongst yourselves, but in reality there are those of us, behind the curtains, reading and listening! I just wish I hadn't wasted all those years listening to the incorrect load setting!
Ending with a sincere thank you very much!!
Lou
Showing 3 responses by dover
I think it depends on the individual design. I know from first hand knowledge that the BMC & ESE Nibiru react differently with different cartridges, but on the other hand I have a bespoke current sensing device built by a cartridge manufacturer that is superb across all my cartridges ranging from 3-40ohms internal impedance. Also I recall the current sensing Goldmund PH2 sounding superb across a variety of cartridges, regardless of internal impedance of the MC. |
I gave up when Raul confused cantilever material with cantilever motion ( see quote from Raul below ). The reality is that any change of loading will possibly have an impact on "tracing the groove". The Shure white papers explain this clearly with their testing on groove tracing and the impact of changes in compliance - at worst they describe scrubbing motion of the stylus/cantilever from mismatched arms/cartridges. It is the genesis of the use of their stabiliser brush. Tracking tests on records do not measure distortion - they only indicate a tracking ability ( crudely ). In my view there may be no obvious mistracking from altering the loading, but there is the possibility of a change in tracing and distortion ( for better or worse ). If Raul loads all MC at 100ohms, then likely he cannot hear the impact of changes in loading, or he has a low resolution system - or both. As an aside I agree with JCarr's and your comments that loading is more about taming poor quality phono stages with poor overload margins at ultra high frequencies. Folk need to understand that, like brick wall filters in early digital, problems at ultrasonic frequencies can generate artefacts down into the audible region. Perhaps Rauls home brew preamp is in this group which would explain why he needs to load all MC's at 100ohms - which is extremely low - particularly for cartridges with an internal impedance above 5-6 ohms. It's no wonder that Raul thought for years that he preferred MM cartridges most of which have large phase shifts and frequency aberrations in the audible region - necessarily tuned by loading R & C of course in order to get a reasonable facsimile of a linear phase coherent response.
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