Does phono stage noise drive you crazy too?


After using high output moving magnet cartridges for many years, I recently purchased a .5mv output Grado Master 1. I thought that it would be a decent match with my Acoustech Ph-1p phono stage. Reviewers all claim to have used this phono stage with lower output cartridges and had no noise issues that bothered them. I'm just wondering if I'm unduly sensitive to electronic circuit noise, as I find the pairing to be obnoxiously noisy. There's no hum issue, just a "white noise" kind of circuit noise. When I have system volume set to normal highest level listening, I can hear the preamp hiss from the listening seat nine feet away from the speakers. It's not louder than lead-in groove noise, but it contributes to an electronic haze that obscures low level micro-dynamics. I've got the preamp set to 61db. of gain (53db. A weighted noise it turns out.) The Master sounds lifeless and anemic at the lower 52db. gain setting.
Is this state of affairs common? Do many of you just learn to listen through this low level noise haze? At present, it seems that I either need a cartridge with .8-1.0 mv. output to be able to use less noisy gain if I stick with the Acoustech, or I need a phono stage with a better S/N ratio. It surprised me when I started looking for A-weighted phono stage specs, not too many manufacturers seem to want to list that spec.
photon46
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
Dear Photon46: Maybe I'm wrong but you Aloia preamp has the phono option that maybe could works better with your Grado.

You posted that with 52db on phono gain the performance is anemic.
52db + at least 10db additional gain from your line stage is a lot of gain and IMHO enough for that Grado for not have that problem and certainly not for sound be anemic.
So IMHO there is a mis-match between that phono stage and the Grado or that phono stage is out of specs.

Btw, check that the Grado pin connectors are connected in the right way and makes tight connection with the tonearm four wires.

Why don't try the Aloia with phono card?.

regards and enjoy the music,
Raul.
Al, I reinstalled the Grado on my arm and then set the resistive loading to 100 ohms instead of 47k. That does ameliorate some of the problem. The character of the noise is now softer, less high frequency hash in the circuit noise. I'll have to see if I can try a proper moving coil and see if the ultimate answer is going to be a different cartridge or phono stage. I really like the character of both the Grado and the Ph1-p, but they aren't an ideal match it seems.

Raul, I definitely thought about trying an internal phono card in the Aloia, but the factory won't respond to emails and there isn't a U.S. distributor anymore to my knowledge. There have been a couple that popped up on Audiogon with the phono option, but what holds me back is my doubt that an internal phono card is going to equal the ultimate potential of a high performing stand alone phono stage.