Convert cartridge output voltage to db gain

Phono preamp gain computer at kabusa.com (click on phono preamps and scroll to the bottom of the page) shows you need 63 db of gain. I'm with Kal above; unless you are running a system with very low overall gain in your actual preamp further up the line (say a passive) or extremely low efficiency speakers you need less gain not more or, a lower output cartridge. Sounds like the integrated you are running has a bit more gain than the component(s) you replaced.

Once you hit into low output MC's, getting the gain right is very critical. My guess is that the "higher noise floor" you are hearing is a result of too much gain and the noise and hiss being amplified as a result of that. You might also have a very slight hardening of the sound as a result of too much gain. Go higher gain and your problems will become even worse and your sound quality will deteriorate even more.

"Kal, you are right, I looked it up, and the preamp stage in my integrated amp has 11 db more than the gain of my seperate preamp. So more gain may be a bad thing."

Bingo. The key thing here. Your system in its new incarnation is amplifying the noise resulting from the slight mismatch (slightly too much gain) you have with the phono stage and cartridge.

Get your gain on the phono stage into the 63 db area or get a cartridge with an output of .17 mV and your noise problem will disappear. Things will sound better as well. Getting the gain right will be much easier, less costly, and less time consuming than coming up with a new cartridge!

Al: In this case, lowering the cartridge output (or reducing the gain for that matter) would indeed result in John having to run the volume pot higher with phono, but as you point out in your last paragraph that is only an issue if he's running full out on the volume pot of the integrated and that is (and IMO won't be the case with a reduced gain of 3 db at the phono stage) not the case.

IME, the noise or hiss that he describes is totally consistent with too much gain at the phono stage. In effect, the phono stage is either on the verge of being overloaded, or is being overloaded by the cartridge which has too much output for the amount of gain on tap. That manifests itself in the hiss which he's describing as well as a bit of hardening up in sound quality and a collapse of soundstage, particularly front to back.

Not having enough gain can also create noise problems as well as totally squashing dynamics and giving the effect of listening through about 3 wet blankets.

Particularly with low output MC's having outputs in the .15 to .35 mV range, dialing in the gain is critical. Get 3 db in either direction on the wrong side at the phonostage and you have problems, 4-5 db wrong or more and it's not worth listening to. And those problems cannot be rectified further on down the line than the phonostage.

Changing tubes may indeed help. I don't have much experience with tubes to be candid. But I would expect that if that was to help that the tubes themselves might, in fact, be altering the overall gain that the phono stage is ultimately providing.

I would be curious to hear what Lloyd Walker would recommend in this situation, but I do think it is a gain issue and that the phono stage has too much gain for the cartridge being used.

Another factor to consider is that the .24 mV cartridge may in fact have an output slightly higher than this. Both of my 103R's, spec'd at .25 mV came with data sheets showing testing on the individual cartridges and outputs higher than .25 mV. The one that is closest at hand shows an output on one channel of .31 mV and .32 on the other.

If this is the case with the OP's cartridge it would be an argument for possibly further reducing the gain in the phono stage.

If you just want to match the output of the CD player to your phono, just use attenuators on the CD player inputs. It will be a lot easier.

But it won't address your noise issue on the phono side. Plus a 1.2 mV cartridge with a phono stage delivering 80 db of gain is going to sound absolutely horrendous.

Clarification above: attenuators would be on integrated's CD input.