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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

Showing 6 responses by photon46

photon46 OP
1,076 posts
 
Thanks for your responses. There is no mismatch as to loading or capacitance. In fact, Grados are unaffected by capacitance if one believes factory guidance. I'm running around 250pf of capacitance (cabling + preamp) & 47k loading. Tonearm cabling is a brand new continuous litz loom in the Audiomods arm I recently bought. I don't want to make my noise obsession sound as if this is a really blatant problem. I'd imagine many people wouldn't notice or care. It's just that with something like my high output Garrott Optim FGS, there's a noticeably better signal to noise ratio. The volume level of any given lp's mastering is a factor too. Elvis Costello's "My Aim is True" MFSL remaster has a lower than usual volume and it's particularly noticeable playing that lp.
photon46 OP
1,076 posts
 
I suppose I might also mention that a low output Grado, as the factory has stated to other Audiogoners, doesn't seem to care what resistive loading it sees. It sounds basically the same running into 100 ohms as it does into 47k. I'd never bothered to test this before, but it's true as far as my ears can tell.
photon46 OP
1,076 posts
 
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.
photon46 OP
1,076 posts
 
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.
photon46 OP
1,076 posts
 
When I reinstalled the Grado, the first thing I did was to try it at the lower 52db. gain setting again. It did not sound "weak and anemic" anymore at that gain setting, so I surmise that I must have underestimated how long it was going to take for a brand new cartridge to break in. When I adjust the phono gain to either 52 or 61db. gain and then set system volume to a measured 79-80 db. playback level, the background circuit hiss sounds pretty much the same to me. Don't know what to think about that, confounds my expectations as well.
Thanks Al for all the advice. It would be interesting to run a frequency analyzer on this combo to see what the frequency response is. If there's a severe roll off above 8khz., my middle aged ears aren't hearing it yet.
photon46 OP
1,076 posts
 
I thought I'd post an update. After doing a bit of further research, I thought I'd try something a little higher up the audio food chain to see if a more compatible preamp with low output Grados could be found. A couple of emails later and I had one of RCM's Sensor Prelude phonostages courtesy of Mehran at Sorasound headed my way. After living with it now for a few weeks, I can say this has been one of the best audio purchases I've ever made. It took what virtues the Acoustech PH1-p had and expanded upon them, added tonal density, and does everything with much less background noise. It's a truly excellent sounding product that balances insight and soul. Using the Grado Master at similar gain settings with the RCM and the Acoustech proved once again that while specs may be similar, numbers don't tell the entire story.
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