The correct internal-inductance of Windfeld cart.?


What (on earth) is the correct internal-inductance of the Ortofon Peer Windfeld cartridge?

They made a mistake in the brochure about the loading impedance: it says >10k but should read >10 ohms. This was admitted by the factory's techies.

The brochure also says internal-inductance: 700 mH !!!
This you would expect from an MM cart. Was this also a factor 1 000 error? I can not find ANY help on the web to clear this up. Can any one help?
axelwahl
Axel, Now it is YOU who have misunderstood ME. You wrote, "So, the SUT secondary "sees" the 47k input-impedance of the phono-pre! If you put -another- 47k R (as you implied)". No, I did not mean to imply nor did I think that you have two 47K resistors in parallel on the secondary, I did mean to ask whether the sole parallel resistance on the secondary side of your SUT is the 47K-ohm input Z of the phono section. That's what I wrote. Your whole paragraph on the undesirable result of paralleling two 47K resistors is beside the point. I just wanted you to summarize what resistances you have and where they are in your circuit to give you the sound you like from your PW.

And thank you for the advice on SUT installation, but there is no way I am going to be buying and installing a SUT, when my phono pre has oodles of gain and sounds great. I am just interested in your findings.
Hi Lewm,
+++ I did mean to ask whether the sole parallel resistance on the secondary side of your SUT is the 47K-ohm input Z of the phono section.
+++
YES SIR, right as you say!

+++
...when my phono pre has oodles of gain and sounds great.
+++
Well, as with all things --- "sound great" that's relative, no? :-)
And "oodles of gain" got nothing to do with it. My Levinson phono-boards (through my 326S) has 78dB gain if I open it all up (the ML has adjustable input gain +6, +12, +18dB, and the phono-board does 40dB or 60 dB. Believe me, SUTs are only to some degree, and in some more 'needy of gain' situations about gain.
The point I'm making is, that a trannie will make it sound 'greater' still --- but that is a personal thing, like buying another speaker, component, or such. Some day you may recall this little conversation about SUTs, is all :-)
Take care,
Axel
I really think it's quite interesting and unexpected (to me) that with pre-loading of a SUT, the optimal impedance for the PW seems to be about 10 ohms net, whereas, as you say, without the SUT the PW seems to like 500 to 1000 ohms net. I am not close-minded about using a SUT; this is the first report that suggests there could be an advantage notwithstanding any need for extra gain.
I think Axel is spot on with his comments and approach. I'm not quite sure I follow his distinction between "current" and "voltage mode" but maybe that is best for a different thread.

Lewm wrote:

I don't know of anyone else who uses a SUT and loads the cartridge on the primary side.

I covered this in a short thread back in november which can be found here

dave
Thanks very much, Dave. I bookmarked that thread for future reference. But in your experience with primary vs secondary loading does it often occur that the optimal net load for a given cartridge, when you load the primary of the SUT, is radically different from its optimal loading when there is NO SUT or when the load is in the SUT secondary? I can see how that could happen due to introduction of the SUT, thanks to the post you cited.