[bajaed]

Just had my Jasmine phono stage repaired/ upgraded w new caps resistors etc and it sounds great other than the following two problems. The terrible buzz I get when the plasma is on is back and worse than ever. Given that I like to watch tv while listening to music, I need to get this fixed.

The TV, phono stage and amp are all plugged into the same power strip. If I try a cheater plug, which device should I use it on? I'm assuming the phono stage because I did not get any buzzing when I was using a borrowed Bellari 130 with 30 db of gain(too little gain for the new Dyna 10x5 but it was clean and quiet). Should it be used on the tv instead?

I also just noticed another problem w the Jasmine/10x5 that I did not have when I still had a Goldring MM on the table. When I crank the Chronus Magnum above about 2:30 I start getting a bad  feed back hum. Goes away when I turn it down to 2:00. My table is on the same shelf as a speaker about a foot away. I have some Herbies isolation pads on the table and speaker. Again, this was never a problem when I had the mm, but is now that I have a homc. Obviously I was not turning up the amp as high with the mm.

[Charles Xavier]

Just had my Jasmine phono stage repaired/ upgraded w new caps resistors etc and it sounds great other than the following two problems. The terrible buzz I get when the plasma is on is back and worse than ever. Given that I like to watch tv while listening to music, I need to get this fixed.

The TV, phono stage and amp are all plugged into the same power strip. If I try a cheater plug, which device should I use it on? I'm assuming the phono stage because I did not get any buzzing when I was using a borrowed Bellari 130 with 30 db of gain(too little gain for the new Dyna 10x5 but it was clean and quiet). Should it be used on the tv instead?

I also just noticed another problem w the Jasmine/10x5 that I did not have when I still had a Goldring MM on the table. When I crank the Chronus Magnum above about 2:30 I start getting a bad  feed back hum. Goes away when I turn it down to 2:00. My table is on the same shelf as a speaker about a foot away. I have some Herbies isolation pads on the table and speaker. Again, this was never a problem when I had the mm, but is now that I have a homc. Obviously I was not turning up the amp as high with the mm.

I'm in the same boat as you. My Cambridge Audio phono pre picks up the same hum. I also like to watch TV while listening to music. I have tried everything and nothing has helped so now when I want to listen to Vinyl I just keep the TV off

[Gzerro]

I had a similar problem and the ground loop was coming from the cable TV line. This is very common. If you unplug the signal cable from your cable box or TV does the hum go away?

If that is the problem then you can use a ground loop isolator (available on Amazon or Radio shack for just a few $).

Using a cheater plug on the cable box/TV also may eliminate the ground loop, but not recommended for a long term solution.

Of course fixing the ground loop is the best option. You can try calling your cable company if you determine that is where the ground loop is coming from.

[vinyl_lady]

My experience is the same as Gzerro. The ground loop was in the cable tv line. I bought a ground isolator and put it just before the cable box and the hum completely disappeared. I bought mine from Music Direct.

I watch sports with the tv muted and listen to music. Much better than 90% of the announcers.

[bajaed]

Thanks for replies. Its only this phono stage and only when the plasma is on. Othrr sources, other stages no problem. Plasma off but evreything else on, no problem.

The feedback issue only developed after I got the homc. When I use other stages no feedback.
Certain albums no feedback.

Like to keep the Jasmine if I can figure this out. Sounds great now.

[Gzerro]

Thanks for replies. Its only this phono stage and only when the plasma is on. Othrr sources, other stages no problem. Plasma off but evreything else on, no problem.

The feedback issue only developed after I got the homc. When I use other stages no feedback.
Certain albums no feedback.

Like to keep the Jasmine if I can figure this out. Sounds great now.

Did you try unplugging the cable from the TV?

I googled your PS to see if it was a tube unit and found this interesting comment in a review of the jasmine stage:


"The only issue I really had with the unit is the omission of a “ground lift” switch. The power supply is configured for an IEC cord which is grounded. The problem is that if you have something else grounded in the system, a preamp or amp but not both, you will generate an instant ground loop. Ideally, only one component will be grounded. Trust me on this. For lowest noise floor, you can only ground one component in the system, and usually the best choice is the preamp. Along with the LP2, Jasmine sent a very nice AC power cord which is very well made. I had to use one of those orange ground lift plugs to help get rid of an annoying hum (120Hz, I think). Those things are quite cheap, and I didn’t want to modify the unit or the power cable. After that, it was just a matter of waiting for the unit to break in."


http://dagogo.com/jasmine-lp2-0-se-phono-preamplifier-review

[bajaed]

Good find. The phono cable is grounded on the back of the Jasmine. Can't think of anything else grounded via cable or external
  Wire

[avahifi]

I have users tell me that the issue is that some plasma TVs put low level DC on your AC power lines that can cause hum in other components.  In some cases our HumDinger has fixed the issue.

This may not be your issue, but one way you could find out is to plug your plasma TV into a long extension cord running to an AC outlet on a completely different circuit than your audio equipment.

Frank Van Alstine

[Charles Xavier]

I have users tell me that the issue is that some plasma TVs put low level DC on your AC power lines that can cause hum in other components.  In some cases our HumDinger has fixed the issue.

This may not be your issue, but one way you could find out is to plug your plasma TV into a long extension cord running to an AC outlet on a completely different circuit than your audio equipment.

Frank Van Alstine

What if the phono pre uses a dc adapter ?