@ atmasphere
So what is the cutting curve? Can you show us please?
So what is the cutting curve? Can you show us please?
Does anyone care to ask an amplifier designer a technical question? My door is open.
@atmasphere Does anyone find this interesting or alarming that we call the RIAA curve the big one and not make much mention that it is for velocity transducers only? No. Its well understood that is the case. There has been some controversy over other types of transducers as you point out, won't be properly equalized. IMO/IME the producers of such cartridges should offer their products with an equalizer to set things right. Would readers care to comment that this is news that the RIAA curve is only 12 db not 40 db bottom to top. Producers of amplitude cartridges do provide EQ, they have to in their box that powers the cartridge. Sao Win tried to EQ mechanically with little success. I built the equipment so he could measure his cartridges (which he did not before). Soon after he gave it all up from frustration of lack of uniformity. A year or two ago the Panasonic cartridge was reviewed with its"box" and there were great errors found in the resulting frequency response. The reviewer was a bit disappointed that these people could not get it right. |
There have been a few other strain gauge cartridges offered with similar issues. So what is the cutting curve? Can you show us please?Yes. The RIAA pre-emphasis is the algebraic sum of the ordinates of three curves, each expressed in dB: A parallel L/R network with a TC of 3180 milliseconds A series RC network of 318 milliseconds A parallel RC network of 75 milliseconds From top to bottom the range is a bit over 35 dB. |
I'm sure someone can understand my prior answer. I know you can, therefore to your first question, 'yes'. To the second, also 'yes' but the question you asked didn't have a simple answer- some questions are like that :) To the third, a correct answer requires a correct question- the **response** is not raised; the **pre-emphasis** is, and by about 5 db (so the simple answer is thus 'no'). Remember that the curve is just that and is the amalgam of three timing constants. The range of frequencies to which you refer is the area where the response is relatively flat compared to the rest of the curve. It isn't flat because of the ordinates of the timing constants. So its a gentle curve in that range, and the **pre-emphasis** is 'lifted' by about 5 db over that range, not 12. There are plenty of images on the web. Fig. 2 of the article at the link below is pretty good- you can see the 5 db or so rise in the pre-emphasis in the range of frequencies about which you asked: https://www.stereophile.com/features/cut_and_thrust_riaa_lp_equalization/index.html |