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Is RIAA equalisation enough for Phono Stages?

This question was bought up in the latest HiFi+. In particular, the editors report back from the Dem he put on at the Rocky Montain show. To summarise the argument, he says that even after all companies signed up to use RIAA in the 70's I believe, in fact they did'nt. The poor results from DGG in particular, with screetchy, painful treble, is all due to this. Played with the proper correction, they are transformed.
Now a number of stages, both cheap and expensive, provide alternative equalisation, but not all, including many expensive ones. I believe Graham Slee at the cheaper end, EAR, Manley Steelhead, Zanden, all do, for example. Should it be a more important considerration in choosing a stage? Looking at discussions on this site for example, it does not seem to come up much.
david12

Showing 3 responses by eldartford

eldartford
4,262 posts
 
My first phono preamp was a Heathkit, and it had separate switch-selectable "Turnover" and "Rolloff". Damn nuisance!
Standardization was the right idea.
eldartford
4,262 posts
 
It's called an equalizer.

People who distain equalizers conveniently forget the RIAA process.

As I have commented before, what vinyl really needs is dynamic equalization, similar to Dolby for mag tape, and actually developed several decades ago by DBX. It not only made vinyl as quiet as CDs, but dramaticly improved cartridge performance by always having the signal near the optimum level. CDs, and corporate greed on the part of DBX who, unlike Dolby labs, would not allow other hardware manufacturers to use their patents, killed it.
eldartford
4,262 posts
 
Piedpiper...I agree that unnecessary equalization is a bad idea. Along those lines, I have experimented with a biamplified phono preamp. We (RIAA) go to the trouble of boosting the low frequencies, and then we use a crossover network in our speaker that cuts the lows back down for the signal going to the mid/tweeter. I found that feeding the tweeter with the raw (no RIAA) signal with just a passive filter to roll off the boosted highs gave remarkable clarity. Of course the woofer needs the usual RIAA LF boost. For this approach to work the design of the preamp and the speaker needs to be coordinated, and some provision needs to be made for signals that are flat, Tuner, CD, etc. A good DIY project, but not suitable for the mass market.

As for the tape hiss on pre-Dolby master recordings, you don't need a "high resolution" system for this to be evident, and, IMHO, annoying.
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