Hum starting between -85 to -80db

[Craig1512]

I was getting hiss and hum using the Benz Micro Glider MC going direct to the phono inputs on my 440 Pro. A friend who has a lot of experience with turntable's and set up, came around with an Ortofon 2M Black, to try out, he thought the higher output would solve the hiss & hum. He set the 2M Black up on my VPI Prime TT, we did a new config using the default settings for the 2M Black in configurator. When the input was selected to Phono, the hiss and hum was quite bad, worse than the Benz Micro. My friend tried many different settings, tried with and without the ground cable, he even tried a few different interconnect cables, all resulted in no change to the hiss and hum. My friend then decided to disconnect the cables from the phono inputs on the amps, the hiss and hum had lowered a bit but was still there, interestingly I went to the level meter bars in the menu and was surprised to see the green level bars sitting around the -60 mark. My friend stated that this is quite alarming that a phono stage would have so much noise. This was repeatable using the phono input on the Master and the Companion. Again this was with no cables whatsoever attached, the level bars went up slightly when the cables were attached. The hum & hiss is really noticeable at normal to loud listening levels in between tracks and on quiet passages of a track. My friend ruled out it having anything to do with the rest of my system as seen in my signature, I have very good power feed from the PS Audio power regenerator and very good isolation of the turntable on my SolidTech rack.

Does anyone here have a similar experience with this level of hum & hiss? do the level meters sit around the -60 mark? any ideas about how to resolve hiss & hum?

I really don't want to go down the path of purchasing a separate phono stage or SUT, the whole idea of an integrated amp is to reduce component box count. 

My friend was surprised to see this problem in a high end expensive amplifier and suggests this is something which Devialet need to fix.

[ogs]

I agree with your friend, but I'd take it a step further. The phono inputs on your amps seem broken. I've been wondering a lot about this. Some report very good and noise free reproduction with lowish output MC carts directly connected while others with similar cartridges can't listen to music due to noise. You even have noise with a MM cart. So there must be some flaw inside the amps. Either a variation (fault) in the phono module itself or maybe bad internal cabling?

[baddog]

@Craig1512 Ok so here is what I found on my system. This is a D440 Pro that has upgraded Core Infinity Board.

With the Devialet set for the Phono input which has a VPI turntable connected to it with Ortofon Cadenza Black cartridge and Analog Drive System for the turntable. I am using Audio Sensibility cables to connect the turntable to the master. The turntable was turned on, no record playing.

The meters were sitting at the -100 mark. No noise, hiss or hum. Volume control was around the -25 mark.

I would concur with @ogs that it would appear to be an issue with your Devialet. Is this the first time you have connected a turntable to it?

[Craig1512]

@baddog thanks for your feedback on this and reporting your observations with the level meter bars. I have had my VPI prime in my system prior to the Devialet's, however, the hiss using the Micro Benz turned me off listening to Vinyl so hadn't been using my TT much. I'm getting the same result using either the Master or Companion, so I would be surprised that both phono inputs/boards have a fault. My 440 Pro's are due for the CI board upgrade, I will lodge a support ticket with Devialet and have them check the Phono stage when the CI board is getting installed. My friend has made a ground cable with good quality luggs to fit the Devialet's ground post and will be back to do further tests, it was really awkward to get a good connection using bare wire to the ground post due to its location under the Phono inputs.

[baddog]

@Craig1512 Interesting point that you have a problem on both the master and companion, I would concur it is very unlikely to be a hardware issue with the Devialets. Any chance you could borrow someone else's turntable to try in your setup? Any chance you could post your Configuration settings for the cartridge, maybe someone can spot something that is askew?

So you have already tried a different phone cable from turntable to Devialet, and you have a ground wire attached between the Prime and the Devialet?

Yeah short of pulling out the Devialet and attached the ground wire first, it is a tad awkward securing the ground wire to the ground post.

Just one crazy thought, what else is attached to your Devialet? Have you tried checking the meters with the only connection to the Devialets being the power cords, the connection between the two Devialets and the phone cable? Even crazier have you tried swapping out the cable you are using to connect the two units with another one?

Maybe try it with the Devialet and turntable plugged into wall rather than the power conditioner?

No heavy magnets near the phono cartridge?

[Soniclife]

All the stuff bad dog suggested, plus try a single stereo amp, or even taking a single amp to a friend's who has a turntable and see if it's a problem there.

FWIW I think you're picking up mains hum from a power cord, or transformer near the TT, the cable or the amps, look at cable dressing, component positioning, and anything else you can think of.

[Craig1512]

Thanks @baddog and @Soniclife, my good (and very patient!) friend came over today armed with cables and a Rega RP3 TT with Ortofon 2M Blue. Picking up on Baddog's suggestions, heres what we tried and tested.
1. Took the PS Audio P5 out of my system, used 2 stock power cords plugged directly to the wall socket, therefore no other equipment had power to it.
2. Turned anything off in my home that we thought could remotely cause electrical interference, my house is only 2 years old, so electrical's should be okay.
3. Took out my VPI Prime and connected the Rega direct to Dev phono input, used pre sets in Config for 2M Blue.
4. Put my VPI Prime back, tried several phono cables, Cardas Gold Ref, Crystal Picolo Diamond, Audioquest Wild and a couple of varieties of cable made by my friend using Furutech cable and connectors, tried with and without ground cable.
5. Took the Companion out and setup my Master only as a 220Pro

Unfortunately none of the above resulted in any change to the level bars sitting around -60db and the hiss/hum/buzz. The only way to get the level bars down to around the -100db mark and no hiss/hum/buzz was to reduce the Loading to its minimum. Of course this had a dramatic effect on SQ, the Loading for a 2M Black needs to be set to High, as per the Config pre sets. 

This is frustrating, the 2M Black in my system sounds really good, I am very happy with the SQ I am getting, betters the Benz Micro Glider MC. The hiss/hum/buzz is noticeable in quiet passages, in between tracks and with the tone arm lifted, from my listening position (about 2m from speakers) at around -30db volume, my usual listening volume level is around -20db, this is not loud, its just a comfortable listening level.

My friend is convinced the Moving Magnet side of Devialet's phono stage is noisy and not optimal for vinyl playback. I really like the Ortofon sound, my options are to move up the Ortofon chain to something like a Credenza Black MC or similar. Or look to a separate phono stage component, but as I have stated in earlier posts, I am trying avoid adding components into my system. 

BTW, the Crystal Picolo Diamond was the best sounding cable, I was very impressed with SQ with the Picolo used between my TT and the Dev.

Images below is what I am seeing on the Dev screen and my config.

   
   

[Soniclife]

Most odd, the MM stage is normally extremely quiet, I'm baffled why yours isn't. Do you have a dealer you could test your amp at?

[ogs]

@Craig1512 Sorry to read about your ongoing trouble here. You say "The only way to get the level bars down to around the -100db mark and no hiss/hum/buzz was to reduce the Loading to its minimum." ...this would be like putting a short on the input. Should produce little or no noise. Did you contact Devialet support? @Soniclife has a good suggestion. Or you could maybe borrow a single 220 from your dealer to try?

EDIT: I agree with you that it's unlikely that phono inputs on both your units are faulty, but if the noise is more or less the same on both and you get the noise with MM config and cartridge connected it must be considered a possibility.

[NickB]

I think I had this happen once on my 1000 Pro, it turned out to be a bad update, I redid the software update on both Devialet's then made new configs and it went away. If you have already tried this then sorry to waste your time.