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Help w/ noisy gear

D

derdyman

New Member
Hi All, humbly asking for help as I'm at the end of my rope with this. Hope I don't get crapped on here.

I have adopted a one-source policy for my systems. I like having my entire prodigious music collection in high resolution lossless digital format, so I run a Cambridge Azur 851N with my vintage equipment.

I have been using Carver gear. Before I get pilloried bear in mind my ears kinda love Bob's stuff. I can't help it. Before someone says I don't know what musicality is bear in mind I have been an actual musician since I was eleven and I read music and play several instruments. So I know what music is at least. Musicality? I guess that's up to whoever wants to throw crap at me for being a fan of Carver gear (only the Bob era gear, not the post-Bob era gear).

Recently I had a beautiful Hafler 945 pre/9270 power amp combo serviced by Rolland Barr. He is a good guy and I've had Carver gear restored by him and have been satisfied. Folks the Hafler gear hates the network player. This equipment has no XLR inputs so I am using the unbalanced outputs of the 851N to connect to the Hafler gear, into the CD input of the 945 preamplifier. I am using six-braid interconnects from Pine Tree Audio.

I can clearly hear what I presume is the central processing unit or the internal data bus of the 851N processing data when I play a track from the USB flash drive inserted into the rear of the unit. As I listen to the noise, I observe it is synchronous with the small light blinking on the USB flash drive.

I get the same noise when changing internet radio stations for example, and once the music begins to play the noise is greatly diminished but not entirely absent.

Whenever the unit has to 'think' it makes noise. So- I believe that the data being processed inside the 851N is the source of the noise.

Now I can experiment further by separating the components by proximity. I have some cheap Monoprice interconnects that would allow me to place them in separate rooms. Also Rolland advised me to get some 3 to 2 plug adapters to rule out a ground loop issue. Carver is lamp cord-tastical, Hafler uses three prong IEC.

I should say I'm not just plugging the gear into the wall socket, they go into a Furman Elite 15i line filter.

Just curious if anyone has any thoughts about this. That Hafler gear has a different presentation than the Carver gear and I really love it. Still love my Bob gear but the linearity of the Hafler is remarkable. I'd like to keep it in my house and not sell it off in frustration. Because, well I bought another pristine 9270 so I can run two in bridged mono for 400W @ 8 :)

Thanks
 
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That shouldn’t happen. Can you you try another amp to eliminate the Hafler? If it happens with another amp there’s definitely something wrong with the 851N. If you’re getting noise on the output of the 851N there’s something wrong with it.
 
OK so to end this - it was a ground loop issue caused by the three pronged power cables. Adding a 3 to 2 plug adapter fixed it. It is now completely silent. Noise floor is way down, very 'black' background. Whereas before I sent it in for service I felt it was all midrange, I now have lows & highs. Very linear in its presentation with excellent soundstage & separation. This gear is pretty good after a full resto!

Anybody out there with these Haflers - if you are having noise issues, give this fix a try.
 
twiiii said:
There is something definitely wrong with the Hafler if you are hearing noise of any kind.
Click to expand...


No, there is nothing wrong with my Hafler. Did you not read my posts? It just came back from being serviced by Rolland Barr. He told me that three pronged power cables were beyond stupid because of this very issue. Now I believe him. He has been an audio engineer for 42 years.

Good old Sideshow Bob Carver knew this as well. That's why all his power cables are lamp cords.
 
To each his own. I never experienced any noise from any Hafler gear we sold professionally or from the consumer line.
 
twiiii said:
To each his own. I never experienced any noise from any Hafler gear we sold professionally or from the consumer line.
Click to expand...

If you want Rolland's phone number I can give it to you so you two can argue about it. You sold gear. Rolland techs it. See the difference? Because I do.
 
derdyman said:
No, there is nothing wrong with my Hafler. Did you not read my posts? It just came back from being serviced by Rolland Barr. He told me that three pronged power cables were beyond stupid because of this very issue. Now I believe him. He has been an audio engineer for 42 years.

Good old Sideshow Bob Carver knew this as well. That's why all his power cables are lamp cords.
Click to expand...
If anything is stupid, it's that statement. Metal boxes containing mains need to be double insulated or earthed for safety. It's the law, at least in the UK and Europe. Now your Hafler is neither double insulated nor earthed.
There are ways to break grounds loops (or prevent them from occurring in the first place), and simply disconnecting the earth is not one of the legitimate ones.
 
By lifting the ground, you didn’t fix it. You eliminated the problem, but raised the potential for another. The chassis of your amp could become electrified. I rented a condo in Florida several years ago and if you touched the stove and and something grounded like the microwave at the same time, you got shocked.
I would try a different outlet in another room on a different circuit and see if the issue is still there. If not, i would check the outlet for loose connection or back at the panel.
 
What techs measure and what we hear are to different things. Otherwise all low distortion amps preamps would sound the same!
We know better than that. Remember if you read most of my posts I am a tech guy first, too.
 
I'm not the expert that other folks here are, but I'd still be wary about running an amp without a ground attached. For a time, a long time ago, I was running my turntable without a ground attached to the amp as somehow it was quieter that way. I wouldn't run a power amp though like that as I could see safety concerns...
 
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