Does phono stage noise drive you crazy too?

Hi, photon46, I'm running an AcousTech PH-1P and it isn't any more noisy than several other phono stages I've used. That's with a 0.23 mV output cartridge set at 52 dB of gain. I do wonder if you've got other problems in the signal chain, as the others mention. For one thing, I wouldn't expect such a dramatic change in sound between the 61.5 dB gain and 52 dB gain settings. Something doesn't seem right.

Running the 0.5 mV output Master at 52 dB of gain and letting your preamp take care of the rest should help to lower noise from the PH-1P (IF that's really where the problem lies) but the Master shouldn't sound "lifeless and anemic" at the 52 dB setting.

Regards,
Tom

Al, I wondered about RFI myself. I experimented with making a copper shield that grounded to the mains plug connection and used Stillpoints ERS cloth to further shield things. There was a very slight decrease in circuit noise, but nothing really noteworthy. The 53db. A weighted noise figure was provided by the factory, not what I measured from my listening seat. Man, that would be loud noise! My wife can't even hear the hiss from the listening position. Like I said, it's not very loud. I'll dig out my shorting plugs and see what happens to the noise level.

Tom, yes I was expecting to be able to use the 52db. gain setting and was most surprised to find it lacking. I'm certainly wishing I'd done my retip exchange for a 1.0mv version instead of the .5 version. Maybe I'm indulging in a bit of hyperbole to say "lifeless and anemic," but at 52db of phone gain, there is a definite lack of drive and "meat on the bones" compared to the 5.0mv Sonata I traded in on the Master 1.

It may just be Grado. try something else. I never found a phono stage that works well with their low output cartridges.

The 53db. A weighted noise figure was provided by the factory

Assuming it is based on one of the commonly used test conditions and reference levels, a 53db A-weighted s/n ratio is in a ballpark that I would expect to result in the audible hiss levels that you seem to be describing.

In addition to trying the shorting plugs, it might also be worthwhile assessing the hiss levels with the cartridge and cable connected and with loading set to 100 ohms or thereabouts, while you are not playing a record but with the volume control set to where you presently use it.

Perhaps the reason for the better noise performance that Tom reported is that the heavier loading (lower resistance value) that he was probably using in conjunction with a LOMC improved the s/n performance of the PH-1P, relative to what it would be with a 47K input impedance. That possibility would seem consistent with Lloyd's observation, as well. 47K input loading would also seem likely to increase rfi susceptibility, compared to a low value such as 100 ohms.

Also, I note that the Grado's inductance is 2mH, which is considerably higher than that of many and I believe most LOMC's, and would not come close at high frequencies to being the near-short across the phono stage's input that those LOMC's would be. The near-short would presumably reduce both self-generated noise in the front end of the phono stage and rfi susceptibility.

Just some thoughts. Regards,
-- Al

Hi, Al; I've been loading the LOMC cartridge at 200 Ohms and 300 Ohms resistance using resistors in the custom loading slots of the PH-1P. I tried 4.5K and 1.0K Ohms resistors but the presentation, while very lively, was a bit too forward (bordering on bright) for my tastes in my setup. I haven't noticed any difference in background noise between the range of 100 to 4.5K Ohms resistors I've tried but I wasn't really listening intently for any differences that might be present. I never did try the 47K Ohms setting.

Regards,
Tom