Phono stage for 0.2mv cartridge?

I am using my 0.2mv cartridge with the preamp phono stage with good results, slightly more apparent volume than the 0.3mv cartridge and the Canary. Which kinda supports my position regarding how much gain I might want.

If the cartridge specs are accurate and are defined on a consistent basis the 0.3 mv cartridge provides 3.52 db more output than the 0.2 mv cartridge under the same conditions. And if the Canary phono stage and the C100’s built-in phono stage are performing to spec the C100’s phono stage provides 3.5 db more gain than the Canary. So those two differences should cancel out, resulting in exactly the same volume settings for the two cases.

However the "if" I began that paragraph with may be a bit too "iffy" to draw any firm conclusions.

BTW, unrelated to all of this I’ll mention FYI that I would expect that you are using the 1.2 volt sensitivity setting of the MC2000, rather than the 2.5 volt setting, to achieve a reasonable gain match between the two amps, assuming you are using the same output taps on both amps and the same type of interconnections to both (i.e. unbalanced or balanced). Although even in that case the higher powered MC1000 amp would still be providing about 2.4 db more gain than the lower powered MC2000 amp, probably resulting in a slight over-emphasis of the bass. (As far as I can see neither amp provides a level adjustment other than the high/low sensitivity switch on the MC2000).

Regards,
-- Al

Hi Uberwaltz,

It’s hard to tell at this point. The additional info you and Goheelz requested will help shed light on that, of course, and your point is certainly a possibility. But given the mention of 90 to 95 db levels and symphonic recordings that presumably have wide dynamic range (probably vastly wider than the dynamic range of most pop and rock recordings), it seems to me that everything downstream could be hunky-dory.

Best regards,
-- Al

@wbs

As I explain later in this post, in addition to providing the info suggested by the others it may very well be useful if you could describe how much difference there is between the volume control settings you would use for a given cartridge with the C100’s built-in phono stage vs. the Canary’s phono stage. I’m starting to suspect that the Canary may be providing significantly less gain than the 69.5 db spec, for whatever reason.

The gain of the phono section of the C100, fyi, is about 73 db for LOMCs according to my calculations (excluding the gain of the line stage).

It appears that inadequate gain in the C100’s line stage can probably be ruled out as a cause of what you have described. The line stage of the C100 is specified as producing an output of 2.5 volts in response to an input of 450 mv. That corresponds to a gain of about 14.9 db, which is very consistent with your mention of a +15 db max setting of the volume control, and which is significantly above average as line stages go these days.

And if a weak tube or other defect were somehow causing reduced gain in the line stage, it would not account for the more reasonable results you are getting with a 0.3 mv cartridge compared to your 0.2 mv cartridges. 0.2 mv is only about 3.5 db less than 0.3 mv.

What **might** be adding 3 db to that difference, though, are differences in how cartridge output specs are defined. See my post dated 7-4-2012 in this thread.

But regarding the gain provided by the Canary phono stage, 69.5 db would boost the rated output of a 0.3 mv cartridge to about 896 mv, and it would boost the rated output of a 0.2 mv cartridge to about 597 mv. And as I understand it brief dynamic peaks of some recordings, especially those having particularly wide dynamic range, can on occasion cause a cartridge to put out several times the rated output. The upshot being that those numbers seem to me to be several db higher than I would expect would result in the 15 db difference in volume control setting you’ve described for the 0.3 mv cartridge compared to digital sources, as well as the difference of 20 to 25 db with the 0.2 mv cartridges compared to digital sources, if you are using unbalanced interconnections in both cases and if the Canary is truly providing 69.5 db.

More annoying typically with symphonic music.

Not surprising, of course. As you certainly realize the wide dynamic range of many symphonic recordings will often result in the volume control being set higher than for most other kinds of recordings, and the soft passages of symphonic recordings will be more revealing of hiss.

Those are my thoughts at this point. Not sure what else to suggest beyond what I and others have already said.

Good luck. Regards,
-- Al

Regarding the Wall Audio Opus 120, out of curiosity I took a look at its description and at a German-language review of it which are provided at the Wall Audio site. I see no indication of what its gain is for either of the two settings of the front panel switch that is provided for selection of moving coil (as opposed to moving magnet) cartridges. "70 db" is indicated as the signal-to-noise ratio it provides for LOMC cartridges. (That being a spec which is generally useless, IMO, because as in this case those numbers are usually provided with no indication of the "weighting" and/or the signal levels they are based on).

For moving magnet cartridges there is an indication which seems to indicate that 2.5 mv in results in 777 mv out, which is a relatively high gain (for MMs) of 49.8 db. But no such spec appears for LOMCs.

@tooblue Did the manual provide an indication of gain for LOMCs?

Regards,
-- Al

Keep in mind that all gains having a certain number of db are not created equal. And that certainly applies with respect to signal-to-noise ratios and consequently to hiss levels.

Although I use the low gain (64 db) version of the Herron VTPH-2 (not 2A) with a 0.5 mv cartridge, Keith Herron advised me when I purchased it that it would also be fine with a 0.3 mv cartridge I was considering at the time. Based on that and based on how quiet my VTPH-2 is I suspect that the high gain version (69 db) of the VTPH-2 (and presumably the VTPH-2A as well) would be fine with a 0.2 mv cartridge. And if you were to give Keith a call I’m sure he would provide accurate advice.

Of course this assumes, as is likely, that your present phono stage is what is primarily responsible for the hiss you are hearing, rather than your preamp.

Good luck. Regards,
-- Al