How do you know what to damp?

Dear Dave: I am not an electronic engineer but this question of critical damping of phono cartridge seems to be widely misunderstood. When I ask my cartridge builder (Allaerts) I have one answer and same question to my phono preamp. (Tron) designer I have a completely different answer. So with some help with Agon designers I try to understand, but finaly nothing. Damping is aparently more crucial with SS designs than tubes, and resisting valors more by tryal than preestablished. Transformers values have a complete different way of damp and again the given value by cartridge maker is not the same depending on the phonopreamp design ( SS, stepup, OTL, OPamp,...)
If you can put some info please feel free...

Hey Jloveys,

For your situation, I would probably trust Jan on this one since he has far more experience with the loading of his cartridge than anybody else. I have no idea why a SS, tube or OTL amp would load a cartridge differently. The SUT does have some additional parasitics, but the load should simply be the load.

The situation I was asking about was a basic test methodology to see the frequency response of a cartridge. It was mentioned in another thread that it was simple to "ring a cartridge" and apply proper damping. From a technical perspective I want to know how this is done so some data can be collected and compared WRT the theory, measurements and the empirical.

I have yet to see a test record with frequency sweeps that go higher than 20Khz or one that contains a square wave so I was simply wondering what the trick was to see the ringing of an underdamped cartridge. It was pointed out to me by Peter of Soundsmith that nothing says your record and playback speeds need to be the same so this is one possibility but I was wondering if there were an "accepted" industry practice.

dave

Dave,
Atmasphere (Ralph) gave me a specific proceedure for ringing a cartridge using a scope, function generator, and resistor setup using a fixed 10k resistor and the variable portion of a 1k 15 turn potentiometer (using it as a rheostat). I will say that it is not as easy as it could be as there is a lot of interpretation. If you are interested I would send Ralph an e-mail ans I would surely screw it up.
Regards,
Mike