Cartridge advice Classic I from BRAZIL

My dear friend Raul

I own several CJ preamps and amps. :-)

He will not be getting 68 db of gain from that phono/line stage.

M~

Good. Now I see why that 28 db figure was weird for me.

Thank's.

R.

Thank you Raul and Macster!

So, since the gain is 40 dB, what is the minimun cartridge output I must use?

What do you guys think of this cartridge here:

http://app.audiogon.com/listings/cartridges-clearaudio-aurum-beta-s-high-output-mm-cartridge-2013-09-26-analog-95076

Pedro

The gain from the phono input of the Premier 3 to its output is almost certainly 68 db, as the response from CJ indicated. However, the suggestions that have been made of various cartridges having relatively high outputs, such as the DV-10x5 rated at 2.5 mv, are also correct.

40 db corresponds to a voltage gain of 100 times. 68 db corresponds to a voltage gain of about 2512 times.

If the overall gain from phono input to main output were only 40 db, a cartridge having a high rated output of 5 mv under the standard test conditions would result in only 500 mv being supplied to the power amplifier under those test conditions, with the volume control turned all the way up. (Preamp gains are specified based on the volume control being at its maximum possible setting). Extremely loud dynamic peaks can result in cartridge outputs that are a few times greater than under the standard test conditions. But given that the input voltage required to drive power amplifiers to full power is commonly in the area of 1 to 2 volts for unbalanced inputs, if the overall gain were only 40 db you would have to have your volume control at max or close to it if you were to ever have any hope of driving most amplifiers to full power. CJ would not design a preamp that way.

That said, I would recommend against choosing a cartridge having a rated output less than 1 mv or so, and preferably more, depending on the noise performance of the particular tubes that are installed. Using low output moving coil cartridges with this preamp would likely result in noise issues. From Stereophile's review:

The Premier Three preamp alone [without a separate head amp or step-up transformer] cannot be used with even moderately low-output moving-coil cartridges like the Accuphase, Argent Diamond, and Dynavectors without the noise and gain mismatch seriously coloring the sound. Even a Koetsu Black is marginal and tends to have its highs rounded and masked, becoming slightly dry and lacking in detail in the upper midrange. The Alpha-l is also marginal, although the problem tends to be a drying up of the upper octaves and a lack of proper warmth and midrange balance.

I believe that the Koetsu Black, which is described as "marginal" for use with this preamp, had a rated output of about 0.6 mv.

Also, as was noted above by one of the others the Premier 3 may provide only a fixed load impedance of 47K, which would make it unsuitable for use with many and probably most low output moving coil cartridges.

The Clearaudio cartridge you linked to looks fine in terms of electrical compatibility, except that the 100 pf load capacitance that is apparently recommended suggests that you should try to use a phono cable that is short and that has low capacitance per unit length.

I have no knowledge, though, of how optimal a match the Clearaudio's mechanical characteristics (compliance and weight) would be for your particular turntable. Perhaps others will comment on that.

Good luck with your purchase, and with your studies!

Regards,
-- Al

Thank you very much Al, you were very smart to pick that information out of that review. You really helped me to choose a well matched cart to my new TT.