To Aesthetix users

Hi, I have the Io Sig w/VC and 2 supplies. I live in a very RF rich environment near a hospital. On one occassion when trying different ICs I did discover some RF bleed through.No hum with the IO or subsequent RF problems.

Your IC's must be very well shielded and you must exhaustively experiment with dressing the leads and positioning with equipment and try different brands.While not the best, Musical fidelity make a type with RF ferrite clamps on the cable...it may be worth a try to see the result. In the past when I had a Counterpoint head amp this problem would drive me crazy.

Fourtunately the Counterpoint weighed in at about 5lbs so you could wave it in the air and find a good position. Hard to do with the Io.

Also make sure your connectors are scrupuously clean. Any oxidation and the connectors will act as diodes in a cyrstal radio singing through your system.I like the Caig products here not comfortable using any of the silver based contact enhancers as they can be difficult to clean out of the connectors if it does not work out.

I doubt that your electrical system is properly grounded if you had to add new grounded receptcles to replace 2 prong ones. If you have armoured cable or conduit(maybe in NYC) then the outer sheild/conduit may be acting as a poor ground back to the main panel. Get a electrician to seen if you have a "separate" ground wire back to the panel and properly bonded to the neutral at the box. Old vinyl gave good advice on disconnecting and swapping Ic's to discover if the problem is the Io or the amp for hum... working from the source forward to determine the possible cause...don't ignore the dressing of your tonearm cable.

This is exhausting and thankless work but it can be done..goodluck!

Hello,

A couple of other thoughts:

* You obviously do not have a continuous ground through to the receptcle. If you unscrew the receptcle from the box and leave it in free space then your ratshack tester will show a missing ground. I don't know your electrical code (I'm in Canada) but I understand that in major centres like Chicago and probably NYC conduit is required in commercial/multiunit applications for fire code and protection from pests. If you are comfortable you can mechanically bond a ground wire from the recepticle to the recepticle box with a screw.You'll still have a problem on the other end though with perhaps poor bonding of the conduit to the box... the whole system circa 1955 may not be grounded anyway? An electrician's advice is good here if you are not savy in opening up your main panel for a peek.

* You could try running an extension from your AC outlet to the Io just for fun and see the results.

* If the AC line works (or even if it does not) and you can make the investment in one dedicated circuit back to the panel then this may be worth it to eliminate clicks and pops from other appliances. Decorative panel mold conduit is available to make the run as unobtrusive as possible.

* You are running the Io full out with possibly an improper ground in NYC (RF hell I imagine) so you may have to back off a bit. This is a function of the overall sensitivity of your system from cartridge to speakers and the room interface. I'm thinking this is your real problem!!!

* Try eliminating your power conditioner on the other equipment and see what happens to the hum... make sure you have no other inputs tape,tuner etc connected to your pre. They may be causing a groudloop via the common buss on the pre back to the Io.

* Start swapping cables L-->R and tubes L--R... If you have known good tubes for the PS supply swap them in. If it bothers you enough and you don't want to ship the unit for testing then perhaps buy a complete tube set and try swapping them in (for god's sake mark them first so you don't confuse yourself...ask me how I know)...man I'm getting tired just thinking about it!

The good news is the Io is very silent on my system so I know you can get there with this equipment with proper wire dressing, grounds, and good tubes.

All the best

Hello, Patrick

You may be getting close. Definitely swap the front end tubes from channel to channel. Make sure you mark them V1A, V2A, V1B,V2B etc to keep things straight. You may have to work through the whole tube complement to find a culprit.

Bonding of the receptcle frame to the box is really not good enough IMO the box is oxidized cadmium plated and you are trying to achieve a good ground...I'd add a wire from the ground terminal of the receptcle to the box if it were me...you still need to check the other end out with an electrician...this point may be minor if there is no ground at the front end anyway.

Try a sheilded ac supply cord from Belden or Volex(P/N 17604) They cost about $15.00 for a 14gauge type from any of the supply houses like Allied Electronics etc.They give similar performance to some of the high priced highend types for a fraction of the cost.

Lift the ground with a cheater to note the result

Try turning down your gain or if you are really adventurous move your equipment around to see the result...clean your contacts!

Jim has always responded to me...he may be busy or sometimes the spam filters don't let you through. You can give a call otherwise.

Please do not attempt to enter the service entrance if you are not qualified to do so. Your risk serious injury or death.

When your electrician looks at the service entrance (panel) there would be, in modern set-ups, a buss termination where all grounds go to..usually bare wires or green wires This buss strip is directly bonded to the panel. There is another buss strip where all white(neutral wires) go to this is isolated from the panel and bonds to the neutral main coming in. Your electrician would be able to see the two distinct buss strips indicating a grounded panel.If you do not see this it is unlikely that you have a grounded service. Have your electrician look at how the latest addition to your panel (the AC) has been added. Is there a ground from this branch and where does it go insided the panel?...this could be a clue..

Outside of panel Take a voltmeter, set to AC, measure from the wide prong of a receptlce to the ground ...should be zero if the receptlcle is grounded correctly. Also measure from the ground prong of the receptlce to the narrow bar of the receptcle should be 120vac.

I'm not familiar with your codes or practices in NYC. This is general information. You need an electrician to look at the main entrance of the service wires: should be 2 black & a white and possibly a ground bonded to the neutral dependant on the era and the codes at time of installation.

Hi Patrick,

Wondered how you were making out. Now no one said this was a science!. At least you're only out some frustration and not alot money so far. I really think the ground issue is a red herring with the RF. To be sure ground is good... But I think you have a positioning problem(think antenna), too much gain problem or interconnect sensitivity problem to RF. Look back on the thread did you clean your connections? A simple move of your equipment could solve these problems if it is possible.

I think audio advisor has some rf clamps that can be attached to cables to mitigate RF. Might be worth a try. If you're really stuck I think I have some of those MF cables I mentioned in my black box of used cables that you could try.. I'm sure we could work out an arrangement for a trial if you wanted to go down that road.

Best,

Nkj

Hi Patrick ,

This is classic and could be endimic to the design. As I had mentioned you are running very high gain for very fragile (small) signals as they get swamped by the RF energy.

The line stage is orders of magnitude greater in amplitude so the RF is riding underneath the line stage signal ..It's still there..

Cables , positioning (think a tuned circuit like an antenna) are bombing the fragile signal and getting through your system. If you had lower gain or inefficient speakers you may not hear it at all. Different cables,tubes, or positioning alter the tuned circuit and may make it go away all together. It is not easy when you are in such a RF rich environment running very high gain of such a minute signal.

Keep trying...try some different front end tubes too...Good luck ,Nkj

Hi Patrick,

FWIW I have had good luck in sensitive Counterpoint products with RAM branded soviet and Yugo tubes from Roger Modjeski. Expensive but may be worth a try in your case.

Let us know how you get on.

Good Luck

Patrick, it definitely sound like RF. I bet if you placed the Io somewhere else it would not be affected by the RF. I don't think changing the el34's will do anything. BTW is this noise recently developed?

Hello Patrick,

Keep cleaning your contacts...especially those carrying audio signals. Dirty contacts here exacerbate RF. Moving that Io will make things better or disapear wrt RF.

Are you exhausted yet?!

Hi Patrick,

Good to hear you got the problem solved. If you look back on the threads... I emphasized lead dress as being very important. Nice to have solved it on your own.

Happy listening....