Elac PPA-2 hum trouble.


Okey dokey, I bought an Elac PPA-2 and it has a pronounced 60hz hum.

System is:

Hana ML> Yamaha GT2000> balanced output>balanced input> PPA-2> balanced output> balanced input>Cambridge Azur 851A> Revel M106.

The hum is audible from the listening position at moderate listening levels. It’s 60hz.

Settings are MC/MM 18bd boost gain, variable load at 175 ohms, Hi pass filter on, input 2. (input one does the same thing).

At first I assumed it was my tone arm to balanced cable situation, I had just completed modifying the tone arm output cables for balanced operation and since I’m a glutton for punishment, rewired the tonearm. This led me to remove the tone arm for a work bench inspection. There was no continuity from any signal wire to tone arm ground or from the signal ground to the shield ground. The shield ground is NOT on pin 1 as specified in the Elac Owners guide, and the tonearm ground is to be attached to the correct ground lug (not the chassis ground lug). I reinstalled, still humming.

I again thought I had missed something so I removed it and checked it again. Nothing wrong.

I was reinstalling all that mess, got distracted, came back and turned the system back on and the hum was still there. However, I had not connected the turntable cables and ground. No turntable connection same noise.

I replaced the XLR cables on the PPA-2 output with RCA’s on the single end output and the hum remained, I changed cables again, still humming.

I changed the power cord, still humming. I removed the ground pin from crappy old power cord, tried that and still humming.

I exercised the loading pots and dip switches- that reduced the hum volume by roughly 6bd. (half)

I removed the PPA-2 from the main system and took it to my office system (don’t get excited, it’s a little WXA-50 and some old Monitor Audio speakers.) Take a guess............... you are correct! It still hums.

So at this point I’m pretty sure it’s a PPA-2 internal problem.

The purpose of the post is to find out if anyone else has had this problem and if anything can be done about it, as well as to entertain the sadists in the crowd.

So if anyone knows anything about this I’d appreciate your feed back. Thanks.

 

 

mitchellcp

Great!  - Mind sharing what solved it for you?  

Inquiring minds want to know....

I just bought one and am experiencing the exact scenario you described above. I'm working with just single ended rca's, input 2 is a bit less noisy then input 1. Moving coil setup, with a technis sl-1600C. 

Plug this preamp anywhere and the hum follows, no turn table needed!

So if you did fix it, please let us know otherwise I am rma'ing this ;)

I exercised the pots and dip switches. I also took the cover off and found the connection to the IEC ground was loose. I tightened that up and voila!! I could not return mine because I bought it used. If I were in your shoes I would RMA that thing before the week was out, that’s what warranties are for.