Help with cartridge loading. . .

I don't know, but it was refreshing to read the manual (if you can call it that) that comes with the Rega P9. It seems the designer takes a simpler view of things as they pertain to playing a black disc. I guess everybody is right! My feelings are that unit to unit variability obviously exists, but is probably over hyped. I guess I just don't have that tweaker fibre! I like the notion that vinyl records don't require cleaning since the stylus will simply shove away the dirt in its path. I will soon see how much shovelling of dirt the P9 can actually accomplish. As for me, I will set it to whatever the cart manufacturer recommends and pray for a mild winter.

Sean, good post. According to my in-house scientist, raising the electrical impedance to a cartridge not only requires the cantilever to move more forcefully to generate a signal, it also makes the cartridge more resistant to such movement. Almost like you had the ability to stiffen the suspension. Reducing impedance has the opposite effect of course. Clearly this will effect transient response as well as tracking accuracy at different frequencies. Next time I have a vacation week to spare I'll look up that article by Moncrieff. He's good, but this whole forum combined couldn't outwrite him. :)

Pbb, near the end of an unwashed record the other day I noticed my cantilever had a big pile of fluff on top. Watching more closely, I saw the stylus shovelling stuff out of the groove at a prodigious rate. Most of it ended up on top of the cantilever somehow. When the pile got big enough some of it would actually topple off, only to be replaced by more junk being dug out by the stylus. Who needs TV? I can watch this for hours!

Happily for your "damn the washing, full speed ahead" philosopy, I couldn't hear any degradation of sound, even after I knew the grooves were full of junk. (My old cartridge would have sounded very scratchy in such circumstances, so YMMV. I'm sure stylus geometry controls how well it deals with dirt.)

Of course playing dirty vinyl will shorten the life of both stylus and record. That's just common sense. In my case, while I can apparently play through mounds of loose fluff, the slightest layer of anything is quite audible (mold release agents, inadequate rinse, smog from NJ, whatever). So I wash. That's also the only way to remove anything so stuck in the groove that the stylus won't dislodge it. That stuff causes those annoying pops and clicks, and can do real damage to a stylus.

OTOH, maybe you really should just enjoy the new table. The rest of us are pretty wacko anyway, as you well know!

Doug, I believe the loading resistance value vs. damping question works in reverse fashion to the way you seem to have described it, i.e., the lower the terminating resistance presented to a MC cart, the more damped it's resonance becomes.

If someone prefers to hunt around for their preferred impedance, I have no strong objection. Just don't go below your cartridge's internal impedance. IME some cartridges (eg OC9) are very sensitive to impedance loading. Some (eg Lydian Beta) are not very sensitive to loading.

A lower load impedance loads up the cartridge with higher current, making it harder for the cantilever to move. So the manufacturers spec may also take this into account, to provide optimum damping.

I always use the manufacturer's recommended spec for MC loading. I set VTF and antiskate using the manufacturer's spec and a test record, because I find that minimizing the number of variables allows me to concentrate on finding an ideal VTA. If everything's changing, it gets very confusing, and you can get way off base. This is compounded by the fact that impedance loading and VTA have very similar effects on the sound.

Just a few thoughts on the posts above:
MC cartridges react very little to capacitance. Less is best, because capacitance causes phase shift. MM's require the manufacturer's exact specified capacitance to provide proper frequency response.

Transformers and preamps sometimes carry different impedance specs (eg OC9 says 20R for tx, 100R for a gain stage) because a transformer works optimally with current, while an amplifier prefers voltage. Current is maximized at a point slightly above the cartridge's internal impedance, and that will be the specified load for a transformer. The impedance for a gain stage is spec'ed for a reasonable voltage and current, but maximum efficiency.

Dan Bonhomme

Dan: Using a terminating impedance that is very near or lower than that of the cartridge itself will "load down" the cartridge. This typically results in muddy bass and severe high frequency sag. If one has a cartridge that has noticeable high frequency rise and very light bass, this can be put to use to some extent. Obviously, it is a matter of juggling the variables to arrive at something that you think is enjoyable and works well.

El: I agree that vinyl can be as simple or complex as you want to make it. Then again, it is not called "analog" for nothing. Some think you have to be "anal" to enjoy vinyl while others think it is "the shit" ( aka "log" ) compared to what other formats have to offer. Sorry for the bad pun, but i just hadta do it. If this type of stuff upsets some of you, send an audiophile woman over my way to "reprimand me" for "being bad" : )

Once you get things set up correctly though, it is relatively hassle free other than performing basic maintenance on the records and the stylus. That is, so long as you have good quality gear and your house isn't built over a fault line and gets shaken on a regular basis. I do have to admit that having test equipment and knowing how to use it can make things both simpler and "more accurate" rather than just twiddling, listening and guessing. Just having a scope, reference material and doing some experimentation can teach one GOBS in a very short period of time.

Doug: Since the phono cartridge is basically an "electrical generator" that interprets analogue data and spits out its' interpretation, it is sensitive to both the material that is fed into it AND the demands placed upon it by the load. Changing any of these variables ( quality and cleanliness of data presented to it, tracking angle, sidewall thrust, ability to transfer both electrical and mechanical energy, etc... ) may offer very different presentations.

As far as Moncrieff goes and phono cartridges, IAR Journal 5 ( the big thick one, NOT the "flyer sized" Hotline 5 ) covers quite a bit of info about phono cartridges. Most of it covers older products ( obviously ), but much of the knowledge learned then still applies today to much newer products. Sean