Riaa curve

Atmasphere...What is cut in the vinyl is heard through speakers...the "equation" for what is heard most certainly includes speakers, and a lot of other stuff, and the cutter.

You say that you can find parts that are "CLOSE ENOUGH" to "DO THE JOB". Right on!! That philosophy indicates you don't overdesign.

I am still waiting to hear the frequency response of a typical cutter. and its "pre-emphasis" module.

Eldartford, the unit that I use has bandwidth out to just shy of 30K. The electronics have a bit more than that, but not much (they were designed in the late 60s). I don't think you could say that there is a 'typical' cutter, as they are all designed (like anything else in this world) to meet certain parameters that the designer felt was important.

I chose the unit I did based on hearing the LPs that it was know to have made, and also for the fact that I can get our amplifiers to drive the cutter as well- resulting in the first vacuum-tube transformerless cutter system.

Atmasphere...Ok. I guess I just said "frequency response" when I meant fidelity to RIAA equalization across the whole band. I think that was what we were talking about.

When the record is mastered equalization is usually applied so that the result sounds right to the producer, and when the record is played back equalization may be applied by the user so that it sounds right to him (through his speakers an in his room). With all this going on extreme accuracy of the RIAA equalization seems unnecessary to me.

Eldartford,
you mentioned the cutting lathe and applied (inverse) RIAA.

I would like to know about % deviation found with well regarded 'commercial' phono-pres (not boutique audio).

Looking at the few test graph showings in audiophile’s measurements --- "With all this going on, extreme accuracy of the RIAA equalization seems unnecessary to me." --- it seems some more manufacturer sharing this opinion.

We all know that accuracy will be nice to have in deed, but is it THE prime design parameter I seem to hear it is? Aren't there other much more important ones?

In other words: will it render another product much inferior just because it does not go to the ultimate in this RIAA matter?

Again, (yes, my system sux) listening to my 390S CD and then to the same on LP, I can hear NO colouration with a +/- 1% spec. We also know there are units out there with more than 1% deviation (and not too cheap either).

Eldartford, you are right about that process, but the producer of an LP would never have the EQ of the RIAA messed with! Usually the issue is a private studio and producer have made a recording. They want an LP, so they send the tape to someone who can do that. Usually they also send a tape of test tones made on their tape machine, so the LP manufacturer can set his tape playback to match the calibration of the original tape machine. Then he makes the LP.

The producer then gets a test of the LP and listens to it. He may ask for changes in the tape playback calibration (this is something *very* different from EQ, BTW) in order to get the LP to sound more like it did when the recording was made.

If the LP is being pressed in a different country, this process is often broken. That is one reason why it is so important to get an LP that is pressed in the country where the recording was originally made!

It is a tricky process, no doubt, and full of errors, but one thing that no-one ever seems to mess with is the EQ curves. For the most part, there is a very genuine effort to get the LPs to sound like the playback of the master tape.