Grado cartridge preamp gain

How much gain is necesary with grado black or green in a phono preamp?
40 dB ought to be plenty.
The phono preamp that I use with my Grado Reference (4.0 mV output) has a 35 db gain, which works very well. Anything in the range of 35-40 db is fine with the higher output Grados. For the low output Grados (0.5 mV), at least 60 db of gain is required, and a head amp is often required.
What is head (phone) amp? Also which phono amps have >60 db gain? (Audio research?)
"Head amp" is a term for a high gain device that will supplement a phono stage to provide enough gain for a low output moving coil. Sdcampbell has been around this hobby long enough, like me, to still know the term. You don't see references in the marketing materials to "head amp" much anymore.

Many companies today offer offer units that have more than 60db gain in the phono only. For example: Aesthetix, BAT, Herron, Lamm, Manley, Pass Labs, Tom Evans, and others offer units that have more than 60db gain in the phono only.

Also, consider the total gain of both the phono stage and the line stage when determining how much gain you have available.
According to the Grado web site, both the Green and Black cartridges have 5.0 mV output. Hence, any decent phono preamp with 35-40 db of gain will be more than sufficient. There are several inexpensive to moderately-priced (up to $1500) phono preamps you might consider:
1. Gram Amp 2 ($219)
2. Monolithic Sound PS-1 / HC-1 ($660 for both pieces)
3. Grado PH-1 ($500)
4. Lehmann Audio Black Cube SE ($700)
5. Plinius Jarrah ($850)
6. Phonomenon with BPS power supply ($1200)
7. Benz Likaschek PP-1 ($1350)
8. AcousTech PH1 ($1500)

You might also check with some Audio Research dealers to see if they still have the Audio Research PH-3 phono preamp in stock. It was recently discontinued (replaced by the PH-5), but as a close-out or demo item it is a very good buy.

Last, sorry for using obscure terminology ("head amp"). Rushton was right that the term is probably outdated. Low output cartridges (typically less than 05. mV) often require a "phono pre-preamp" to increase the voltage before the signal is sent on to the phono preamp. This was often done using a step-up transformer, which was commonly referred to as a "head amp".
I played a record through Conrad Johnson PF2 phono/preamp (Gain: Phono Stage 40, 46, or 52 dB selectable, phono overload 65 mV at 1kHz) the volume was very quiet, compared to CD/tape. (I don't know the current setting of the gain)

If this is because its a low output cartridge, should I find a preamp with a gain of 60, get a head amp (are these still sold?) or change to high output cartridge? (fully automatic sony record player) (LX-55?)