yaqin ms-22b picks up radio stations on the phono input.

sharpsuxx · « **on:** 8 Apr 2012, 05:00 pm »

So I was setting up the EE dac in my system using the ms-22b as a pre amp and I was setting the volume controls for lowest distortion when I discovered at Max volume I was picking up a local radio station through the phonograph input. Does this mean I need a new phono cable that has better RF shielding? Better tubes? Or is this just something record players and phonos do?

Certainly wasn't expecting to hear anything more than static and the local radio station was a bit of a sulfide, can't be a good thing for sound quality to have another whole audio track interfering with your sound.

The CD/DVD input is perfect couldn't be happier with it.

JakeJ · « **Reply #1 on:** 8 Apr 2012, 06:23 pm »

My first thought was that you are using an unshielded phono cable. If your cable is shielded then check to make sure it, the shield, is attached to the preamp ground. General rule of thumb for shield connection is landing it on one end only and preferably at the system common ground plane.

One experiment I can think of it to take some tin foil and wrap the entire length of your phono cable, making sure it does not have contact with the RCAs, or any metal associated with them, and leave a tail long enough to contact the ground post. Reinstall them and see if you still have RF interference. If it is still there try touching the tin foil tail to the ground post and see if that eliminates or reduces the interference. If so then you need better shielded cables. Another quick and dirty method just occurred to me before you try the above, turn off the Yaqin, unplug the phono (input) cables, turn on the Yaqin and see if the RF is there. That would mean the Yaqin itself is the culprit and then I would think you live close to a transmitting tower.

You may want to post a link in the Vinyl Circle to this thread to get more responses.

Hope this helps.

JakeJ · « **Reply #2 on:** 10 Apr 2012, 12:55 am »

Wow, no other responses in the last 24 hours. Pretty sad indicator about this circle. Hopefully you posted on another forum and got some help.

Hmmm....

dB Cooper · « **Reply #3 on:** 10 Apr 2012, 03:06 am »

It shouldn't pick it up at all.

I used to live practically across the street from a local radio station. My Dyna amp did not have a problem, but the Kenwood amp I foolishly (and temporarily) replaced it with picked it up almost as well as my tuner did. If extremely high signal strength is the issue, the station is supposed to send somebody to your home to install some sort of 'trap' (they did this for my next door neighbor.)

If it isn't a high-signal condition, it probably has to do with grounding or shielding or both, as others have suggested. NEVER use unshielded cables for phono applications. There could even be a faulty ground connection somewhere in the amp, phono cart, or TT. Phono carts can pick up RF well as I found out when I got my pooter too close to my TT. The tubes themselves are probably the least likely culprit. If you only hear it at high volumes, is it audible during quiet passages at typical levels?

sharpsuxx · « **Reply #4 on:** 10 Apr 2012, 06:05 am »

It is only audible at high volumes during silence. but now I know its there, so I have to fix it. The Phono cable is the shotty stock one with the pro-ject debut 3. Is this phone cable replaceable? Anyways I figure the cable is the culprit as my cd player seams fine and all of its cables are shielded. I'll see if I can ground the phone better. Right now it is hooked into the group connection of the pre amp and the power conditioning is plugged into outlets that probably aren't grounded correctly in my 100+ year old house.

JakeJ · « **Reply #5 on:** 10 Apr 2012, 12:47 pm »

A home that old is likely not to have a proper grounding scheme. Mine was built in 1952 and it does not have a ground except where I've run modern Romex for specific receptacles (stereo and computer). The ms-22b could also be the culprit if it isn't properly shielded, but I suspect you are right about the cables being the most likely "perp".

From the manual I gather the cable is integrated/captured so replacing them would be difficult if you are not big on DIY. However what you may need to do is check the ground wire connection at the turntable and make sure it good (soldered, or if on a post with a nut make sure is is tight, same for the preamp end...tight).

Stay diligent and you will succeed.