I've been to the home of one of the folks mentioned in the article, the listening protocall was to say the least not rigorous. $26K on the word of two partying dentists?
BTW did they mention if they loaded the cart the same for all cuts? If not....
That's probably because Per isn't using cut cores in the LL1931.
That means no air gaps, which means higher efficiency (more like a toroid which also doesn't have an air gap). That means that all else being equal, it will saturate sooner than a laminated core or a cut C core.
se
I've been to the home of one of the folks mentioned in the article, the listening protocall was to say the least not rigorous. $26K on the word of two partying dentists?
The protocol was a joke. The first thing the guy did wrong was to record them on a cd. Since those who swear vinyl is the ultimate recording and MC cartridges the only way to listen to them detest cds with a passion, as soon as any signal passes through that filter they'd consider it all but worthless. And that's just for starters. The article IMO was as worthless as the tests, merely a space filler to sell magazines. Now he had played recordings of dentist's drills, a sound they'd be familiar with.....
being a socialist I actually give them away for a small additional fee
Mr T,
in that case, may i suggest a last name change.
The spec is 0.8nV of noise, not 0.8nV/rt Hz. It doesn't appear to be a noise density spec, nor were they kind enough to specify bandwidth. I didn't see a DCR spec, but from the winding description, it's presumably close to the same as the other good MC step ups.
I think that for Pieter to design the transformer properly, you'll have to spec the input capacitance of the FETs in your circuit.
There is nothing in the review to suggest that the differences in sound cannot be mostly or wholely attributed to minor differences in FR. There is also nothing to suggest that the opinions might not have been entirely different with different equipment, different recordings, different listeners. Considering the cost of even the cheapest of these units, there is no useful information that would lead anyone to make a rational choice between them or to judge whether one or another was actually superior to the others or to far cheaper alternatives. The article is worse than worthless, it is misleading IMO.
Mr Curl,
no pun intended.
It's always a sensible thing to look at the competition, also for checking out potential options, like for instance MC stepup transformers.The Audio Beat - A Grecian Formula - Michael Fremer interviews Demetris Backlavas of Ypsilon Electronics
[ let's hope you don't get hooked on German Telephone (&mail) company C3g's too ]
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John,
At what voltage swing?
For what I can see the mumetal transformer is slightly bigger than the cobalt amorphous one, so it might have a bigger core to begin with.
Besides, the max B of mumetal is around 0.88T, for the cobalt amorphous it is 0.56T.
So anyway as you measure lower in frequency the cobalt core will saturate sooner.
The design (and voltage swing) will determine at which frequency saturation will set in.
In my own experience the voltage swing is not a factor as the MC cartridge puts out so little, and I use already big toroids (but for another reason).
To compare (and draw the right conclusions) you should simulate the voltage swing as it is in practice, and remember that 20 Hz from the record is 10 dB lower than 1 kHz (low frequency voltage swing from the record is really small, rumble and warps not considered).
The saturation point is not the result of whether or not the core is laminated, it is the result of the total mass of the core and the B-H curve for the core material.
A transformer core that will become magnetically saturated by a moving coil phonograph cartridge can't be much of a transformer, especially when you consider that this is a transformer which is external to the cartridge and therefore is not constrained by size or weight while the cores in the cartridge itself do not saturate at the same signal level. The concern about their noise level doesn't speak well for their shielding either.
Mr T,
in that case, may i suggest a last name change.
You may, but actually I feel good the way it is
Pieter, think about WARP FREQUENCY SIGNALS of 1/2 to 3 Hz. This is the key. IF you cannot handle these relatively high level signals coming from REAL vinyl records, you fail. This is the problem, but you are somewhat right, the mumetal core is slightly larger than than the Amorphous core between the two Lundahl transformers, but 20 times more distortion! I use 10 Hz, because that is the lowest frequency available on my test equipment and I will have to go to a special measurement to go down to 1 Hz or so. In any case, the measurement is already showing a significant problem with the amorphous core, and I would bet that your transformers might not do any better, unfortunately. Prove me wrong, I would hope for better performance from somebody, but it may not be practical.
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