davstev
Well-Known Member
Honestly I may be reading it wrong, but the manual for the C-200 seems to state 60db of gain, I think.
Gain requirements: Ultra LOMC cartridges
The Slider
Active Member
The record output value (40dB) is the gain of the phono stage. The main output also includes the main preamp gain. You can get the same from the sensitivity numbers, as I mentioned in my post. The sensitivity shows a gain of 100x, which is 40dB.
whoaru99
Epic Member
Hmmm... I just looked and thought I saw 60dB Disc 1, 2, and Mic to Main Out.
Anyway, think I've tossed out enough numbers to muddy the water. LOL.
The Slider
Active Member
He has some extra control since the C-200 has input impedance adjustment, 30k, 47k, and 100k.
The Slider
Active Member
See post above yours.
whoaru99
Epic Member
I understand, but isn't the ultimate concern for max available gain?
The Slider
Active Member
Not if we are talking about phono preamps. The 20dB extra line preamp gain is there for all sources. The amplifier probably has another 25dB or so gain too, but we don't count it. But sure, if you are trying to set your system gain structure and where you want the volume control to be during normal listening, you need to consider all the gain along with the speaker sensitivity.
That cartridge is indeed ultra low output. The ideal partner would be a SUT with a turns ratio of about 1:45. That would give about 33dB gain and give you enough signal to feed into an MM phonostage. Ortofon used to sell transformers specifically for those ultra low output cartridges. A lot of the Denon transformers have a turns ratio of only 1:10 which isn't really high enough for the MC-20 but you might get away with it if the MM phonostage could be adjusted for a gain of about 50dB rather than the more usual 40dB.
The real issue isn't so much the amount of gain required, it's getting a good signal-to-noise ratio. A high ratio SUT would be best, but even a low ratio SUT would help.
Is it all worth the cost? I suppose that depends on how much a re-tip is going to cost and whether you can find a suitable SUT at a reasonable cost.
That cartridge requires a gain of about 70-75dB. 30dB from a SUT + 40dB from a phonostage would do it, or 20dB for a SUT + 50dB from a phonostage. Btw, the phonostage would need a 47k input impedance for the SUT to work correctly, so there's no point trying to use an MC phonostage for extra gain if it has a low input impedance (circa 100 ohms).
The real issue isn't so much the amount of gain required, it's getting a good signal-to-noise ratio. A high ratio SUT would be best, but even a low ratio SUT would help.
Is it all worth the cost? I suppose that depends on how much a re-tip is going to cost and whether you can find a suitable SUT at a reasonable cost.
That cartridge requires a gain of about 70-75dB. 30dB from a SUT + 40dB from a phonostage would do it, or 20dB for a SUT + 50dB from a phonostage. Btw, the phonostage would need a 47k input impedance for the SUT to work correctly, so there's no point trying to use an MC phonostage for extra gain if it has a low input impedance (circa 100 ohms).
davstev
Well-Known Member
US$250 plus shipping for a retip*, and $200 for a Ortofon MCA-76 (designed to compliment this very cartridge) that I have my eye on. The cantileverless MC-20 cost me $50. Is it worth it? Hard to say at this point, but I can feel my momentum in this direction.
I do already have the Denon HA-500, which has 32db gain. I am a bit dizzied by all the stats and figures in this thread, although I really appreciate everyone's knowledge and input. I think the best thing to do is try both the HA-500 and the MCA-76, and see what it yields.
Having said this, my Denon headamp offers 32db gain, and my Accuphase C-200 preamp offers 40 at least, so we are into the range of 70-75 db, as you say. Perhaps the MCA-76 is unnecessary, but we'll see.
(* retip = 0.14 x 0.07 mm nude 8/18 micron elliptical on a hardened tapered aluminum-magnesium alloy cantilever.)
That will be suitable. The noise won't be quite as low as you'd get with a transformer but it should be low enough. Certainly, it will be good enough to use while you try out the re-tipped cartridge.