To Aesthetix users

Good point Jafox. I don't wait an hour though. Also remember to first disconnect the AC power cable before disconnecting the power supply umbilical.

One other thought about the hum. My SME arm had a DIN-RCA Music Metre silver interconnect that was fine in the first setup. When I moved, this cable picked up hum in the new setup. I tried several well regarded cables and settled on the Nordost Quattro Fil. By far, it had the best shielding (lowest hum). Turns out that it matched ny listening preferences best too.

One way to test this theory would be to simply disconnect the phono leads in to the Io and note if the hum is still there. The next step is to disconnect the hum in to the amo and note if the hum is still there.

Hi guys

I've been travelling in Europe on biz but all these suggestions are extremely helpful. I might also have a bad tube somewhere since the problem is worse in right channel than left when phono is selected, so will try swapping those (maybe the EL-34s in PS) s well as PS cables. Wait an hour before turn-off and turn-on - sounds definitely right with the Io.

The radio reception is there even with the Io not selected. I think it's a cable acting as an antenna somewhere.

I turn off all dimmer switches and halogens when listening to music for the reasons given above.

Will report back, and also Jim White's thoughts when I get him this week.

Best
Patrick

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!

Interesting thanks Nkj.

Yes, I suspect there is something off with the receptacle grounding. There is no ground wire, but there may be an armored cable or conduit - the instructions said that the receptacle could be grounded if it made mechanical connection with the box as you screwed it in.

This sounded screwy to me, but then the fact that my AC polarity checker said that the grounding was fine made me think that in fact this had grounded the receptacle.

Perhaps having an electrician in is the next step? Always pricey and frequently unreliable in Manhattan...

Patrick

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