Thanks for the reply. I turn off the IO after every listening session. I am stationed in Germany and electricity is very expensive here.
The problem is not one that has ever popped up before. I do not need to send it off as the problem has not reproduced itself. I will let the IO stay on this weekend to see what happens.
V/r
Audioquest
BTW...nice system |
Hi AQ4life,
I leave the Io on all the time. This is recommended by Aesthetix and longtime users here such as Albert Porter. Best for sound and for tube life.
I've never heard the whistling high-pitched sound. Do you know if your Mills resistors (used in the first batch of Ios -- they turned out to be bad) have been replaced by Roedersteins? It's a free upgrade from Aesthetix.
Aside from that, I'd call Aesthetix. It sounds like you'll have to send the unit in, unfortunately. Unless it's just a bad tube somewhere. You should switch tubes from L to R starting with the front end gain pairs (12AX7LPs) and if the whistling switches channels, you may have isolated your problem tube. Remember to turn off before switching. |
Hi Patrick,
I have been following your progress with the IO problem. I am a relatively new owner of the IO Signature.
I was wondering if you ever left the IO on for a full day, such as 7AM until midnight, for example...I did one day and noticed at the end of the day that the IO was whistling a high pitched sound...according to my searches it sounds like tube bias getting out of whack or something related to that...how do we test tubes to see if they are bad or going bad, the IO has so many that it will take time..I do not have any problems now, been using the IO for several hours a day, not all day marathons like last week.
Thanks,
Audioquest4life |
Nkj, thanks for all your help... and sorry for missing your earlier post about lead dressing.
Sol, tell me about it! And thanks, it was a journey.
I just tested for RF again with my BAT volume control at 10, 20 and then 30 with no record playing... dead silence... it's uncanny, almost makes me think the system is off!
Now I can't wait for my headphone amp to come back from its repair. This will, of course, be the ultimate test. |
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.... |
Patrick:
What a journey!!!!! First congratulations on solving this bugging situation, what a nice example of fellow 'goners help and manufacturers backing their product.
This reminded me about checking the cable layout in my system. I recently moved and overlooked this aspect. So specially all friends that have the classical rat's nest situation , take your time and improve this to get better sound / avoid unsuspected problems. |
Sorry to revive this old thread, but I finally solved the problem.
It wasn't the RSA Duke that did it... though that is currently installed. Nor was it the balanced tonearm cable from Ikeda... though that is also currently installed. Nor was it Cardas caps on unused inputs... though those are currently installed. Nor was it cleaning contacts, though they're all cleaned. Nor was it the power transformer whine, which Jim White says is normal.
Nope, it was cable dressing at the back of the Io! Due to the Io's dual mono construction, the two phono inputs are widely spaced. With all the tonearm cables I've used, the split "Y" for the Left and Right plugs can just barely be opened widely enough to plug into the Io jacks.
This forced the tonearm cable to rest directly on top of one of the power umbilical cords to the Io power supply.
The clue came when I realized that the RF was much worse out of the left speaker, and then noticed that it was the Left tonearm cable that was resting on the power umbilical cord.
So I grabbed a stick of lead bar solder that I had in my toolchest, stuck it in between the tonearm cable and the power umbilical - and - amazingly - the RF has vanished unless you turn up the volume (nothing playing) to tortuous levels.
Next step will be to ask Jim to make me up a pair of shielded umbilicals.
I thought this might be of use to other Aesthetix owners - or anyone who has a massively high-output, all-tubed phono stage and is experiencing similar difficulties. |
Anyone else notice a high-pitched whine from the PS transformer? The ones at the left-front as you face the power supply. It's not audible more than a few inches away, but I wonder if it's normal. Perhaps they need to be screwed down more firmly. Or perhaps the whole thing needs to go back to Aesthetix.
I'm not assuming this is related to the RF sounds - it sounds totally different. I emailed Jim about it but haven't heard back yet. |
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?! |
Oh yes - from an early recommendation on this thread, I should also mention that I got some DeOxit Gold Cleaner (it came with a free sample of the Conditioner, which supposedly maintains the cleanliness).
First try was on the crappy original AC cord to my Garrrard turntable. This was almost a joke, but it was definitely the oldest and most corroded plug in my system. When we plugged it back in (and played the same piece), my audiophile friend and I virtually leapt out of our seats - the improvement was so marked! Improved bass transients, better resolution, sweeter highs - and this was only on an AC cord turning the turntable motor! Really our first reaction was being more drawn into the music (Enrico Mainardi playing a Tartini cello concerto), and then we dissected the details.
A smoothly turning turntable motor really is an important thing!
Next try was on the AC pins of the Io's power supply. The change here was much less marked, but I guess the pins were much cleaner (and newer).
More results as I gradually clean stuff. I don't have any other contacts with visible oxidation, so that turntable motor cord might have been the big winner.
Patrick |
The latest on my Io Sig and RF saga, if anyone is still reading:
I moved the Io power supply away from the windows (back toward where the system originally resided), which also took it further away from the ExactPower.
Massive decrease in RF. It's still there, but nowhere near as loud. Still a problem if I'm listening to sparse acoustic performances at high volumes, or if I'm listening on headphones.
Next thing will be to try to move both the Io and the power supply even further back into the room, which will need some rearranging, to say the least.
Still no word back from Lenny at Running Spring Audio with his Duke power filter - just emailed him again.
Jim White has been most helpful and even listened to the RF over the phone to try to diagnose. I have a feeling that physical location in my apartment is going to be key here, perhaps with the addition of a dedicated line and/or dedicated power filter for the Io.
Larry, I've got to return your Versalab Red Rollers - thanks again for the loaner!
Patrick |
I plugged mine into a Power Wedge Ultra 116 and noticed a slight buzz. However the buzz was resolved when I plugged it into the wall outlet. |
An update. Jim and I have definitely identified this as RF and narrowed it down to the Io. It's not tube noise and it's not a grounding problem and it's not coming from the turntable. It doesn't make any difference which outlet it's plugged into, and it doesn't make a difference which circuit it's plugged into in the house.
Next test will be borrowing some longer interconnects so that I can move the Io around and see if the RF is being transmitted through the air.
If that doesn't work it, it's a dedicated line to the Io and/or borrowing Running Springs Duke power filter dedicated solely to the Io.
I thought regular readers might appreciate an update!
Patrick |
Hi Nkj,
It's difficult to say whether the noise developed recently, but I didn't notice it until I moved the system in my room, about 4-5 months ago.
Subjectively, though, it seems to be getting louder.
Best
Patrick |
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? |
Hi guys, my Io has the latest resistors, so that isn't the problem.
I haven't tried swapping the PS tubes... no EL34s lying around (or rather there are some, but I'm not sure how good they are). No tube tester either :-(
Patrick |
Have you tried swapping tubes out in the power supply?
If you have a tube tester, it may be time to check out all the tubes. |
Hi Patrick,
I have an Io also. It is about 5 years old. My Io is noisy (tube rush) but not what you are describing. Based on my experience with the Io, the citical tubes are V1 and V2. You already know this.
Take a look at this link:
http://www.musicalsurroundings.com/aesthroedrst.html
I am wondering if this is the issue with your Io.
Regards,
Rich Maurin |
I applaude you efforts to try and resolve an issue as frustrating as this. I had a similar problem with another phonostage that tested my patience thoroughly. Buzz and hum were prevalent in both channels and after several experiments with cables and positioning (solid state unit so no tube swapping), the phonostage went back. Turns out it was an grounding issue involving the chssis. While the vendor fixed it, the whole ordeal left a bad taste in my mouth. It's no longer in my system. Sometimes you just have to move on. |
And a complete report on tube swapping...
V1 & V2
With the new Tung-Sols in this position, the chuff-chuff-chuff was audible in both channels, but much more so in the left channel, with the buzzing sound in both.
V3 & V4
With the original tubes back in V1 & V2 and the Tung-Sols in V3 & V4, the chuff-chuff-chuff was more even between the two channels, and the buzzing sound was inaudible. (!)
V5 & V6
With the original tubes back in V3 & V4 and the Tung-Sols in V5 & V6, the chuff-chuff-chuff was clearly audible through both channels, perhaps even louder, and the buzz was back.
V7
With the original tubes back in V5 & V6, and two of the Tung-Sols inn V7, the chuff-chuff-chuff sound is equal in both speakers (and on headphones), and quite loud - can easily be heard over the music. Now no buzz again (or much less)
V8
I have a bunch of NOS 6SN7s. I decided to try brown-base JAN Sylvania "Chrome Domes" from Kevin Deal at Upscale Audio (probably 1950s) in V8 to see if that made a difference. Once again, the original ECC83s went back V7.
One thing I noticed in each instance is that the tubes in the left channel were appreciably hotter to the touch than the ones in the right channel. Perhaps this relates to the fact the noise was louder in the left channel? EXCEPT in positions V5 and V6, where they were equally (really) hot, and again in positions V7.
Bafflingly, the chuff-chuff-chuff is now much louder in the RIGHT channel... completely opposite to before. I'm replacing the stock 6SN7s in V8 and turning off the unit.
Right now I'm flummoxed. I've emailed Jim with my results, and I have a feeling I'll be returning the unit to him, with PS.
I'm really frustrated. I had become convinced that the noise was due to bad tubes.
Best
Patrick |
Well, that didn't work.
Still the same chuff-chuff-chuff with buzz, louder in one channel than in the other.
I'm gonna move the Tung-Sols to V3 and V4 next. *sigh*... I have a feeling that this unit's going back to Aesthetix for a checkup.
Patrick |
Wow, swift batch of responses! My quartet of Tung-Sols arrived and they are now in the V1 and V2 positions as the unit warms up. I'll report shortly whether this has solved the noise problem.
Meanwhile, Jim and I have been playing phone tag... neither of us is easy to get hold of at the best of times...
And Lenny at Running Springs is gonna have a Duke for me to audition sometime soon, I hope.
Thanks everyone!
Patrick |
Patrick,
I'll address to things that you have brought up on this thread. First, the noise problem. I own a Janus and was hearing something very similar to your description. I replaced the 12AX7s in my phono stage with Kevin Deal's Platinum grade GT12AX7Ms ($35 each for lowest noise and microphony). They sound superb and have lowered the noise floor to levels below that of the stock tubes when new. I can't recommend these highly enough. After rolling in Teles, Bugle Boys, and some very nice Mazda chrome plates, it's clear that these GTs are everything that Kevin claims.
Second, I use both a Running Springs Duke and a TG Audio Bybee Sucker line conditioner. I have connected my gear to these in every way you can imagine. Currently, the JC1s are running into the Duke and the Janus and my Ayre player are hooked up to the TG Audio unit (it has full digital/analog isolation). Regardless of what I have done, the one inescapable conclusion is that the Janus benefits enormously from line conditioning. |
.
Patrick,
.
Try writing to Albert Porter directly and see what advice he might have.
.
He has been playing wiht Aesthetix and rolling tubes in them for quite a while.
. |
I have found that Telefunken ECC83 (12AX7) in the V1 and V2 position significantly reduces noise level and provides incredible transparency.
Another ideal choice would be RCA black plate 12AX7/7025. A matched quad selected for low noise would suit the bill.
Tungsram 12AX7s are way less expensive and also dead quiet. |
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 |
You can try a quad of Ei 12ax7 tubes at $10 each. I use these in the Aesthetix Io's first stage as I have not yet been able to find a quad of Telefunken or Mullard that are as quiet as these. |
Another update... haven't been able to get in touch with Jim for a second consultation, but now I'm fully convinced it's the front end tubes that are contributing to at least part of the choo-choo sound and buzz.
In the meantime, I've taken the gain down from 72 dB to 68 dB, which has at least ameliorated the noise.
I guess NOS tubes are the next step. Or maybe those Tung-Sol 12AX7s.
Patrick |
First tube-switching results:
I just switched the front pairs of 12AX7s - V1L and V2L into V1R and V2R.
The chuff-chuff cyclical sound and the 800 Hz buzz have now switched to the right channel. Still audible from the left, but much louder from the right.
I am now going to mix and match the tubes (I have marked them all.)
Patrick |
Here's the latest:
The chuff-chuff-chuff (like a steam engine) is growing louder - much louder - and is now more audible in the left speaker than the right. There is a buzzy 800 Hz-ish tone as well. The radio station has vanished since I moved the ExactPower. The Io is plugged back into the wall with stock power cord.
The sound can be isolated to the Io, regardless of which cartridge used. It does not occur on any other linestage inputs.
Cello's Red Rollers, which he so generously lent me, did not have any impact on the problem. Cello, I'll be shipping these back to you - thanks for letting me try!
Jim White thinks that I need a power filter between the wall and the Io, and recommends the single-outlet Duke from Running Springs Audio. I have contacted them and they will be shipping me an audition unit. Jim thinks this will be more important than using shielded power umbilicals.
In the meantime, however, the sound has grown louder, and continues to have that cyclical chuff chuff chuff, which makes me suspect an internal component in the Io. Perhaps a tube.
So shifting front-end tubes is my next task.
More as this develops.
thanks for all the continued advice, guys
Patrick |
|
Btw... I took this opportunity to add pictures of each of my components to my system profile, in case anyone wants to check out all this stuff we've been discussing... click the system link below.
Best
Patrick |
Strange and surprising results
So I tried some of changes mentioned in my last post - with surprising results. The most important change in my mind was plugging the Aesthetix PS into the ExactPower. This however meant moving around a bunch of equipment, and I realized that I'd have to switch the 2 preamps with the Aesthetix PS and the amp in order for the plug to reach. This of course also meant that the ExactPower was further away from the low-signal components, as recommended by ExactPower themselves... so I was killing two birds with one stone. (Or doing two tweaks at once - an audiophile no-no of course!)
Anyway, did the switch, and realized at the same time I could no longer use my speaker-level inputs to my sub. They wouldn't reach to the new amp position. So I checked my sub's manual (ACI Titan) and realized - again to my surprise, RTFM! that ACI prefers you to use line-level inputs, not speaker-level. So I ran a spare pare of shielded interconnects from the second set of main outs on my linestage to the sub.
Fired up the system and it sounded dead. No bass - though if I turned up the sub far enough I could feel the woofer move. Strange I thought, it must somehow have gotten out of phase with the rest of the system. I switched the sub's phase switch to 180 degrees and presto, bass. (Obviously I have an inverting component or two in my system, but am not sure which, and am none the wiser after examining the manuals). In fact, much better sub-bass than I'd had with the speaker-level inputs. So I had a totally unexpected benefit from the changes!
In addition, the radio station had entirely vanished from speakers! Yay! But I was still getting the chuff-chuff-chuff sounds, and occasionally a very low hum or buzz (varying at different times). I moved the ExactPower even further away from the other components and this improved, but it's still there a bit.
But there was still something un-musical about the presentation... I didn't find myself drawn into my favorite songs as much, and the soundstage seemed slightly off.
So I powered everything down, unplugged the Io Sig from the ExactPower, plugged it back into the wall, powered back up the Io, waited the allotted 10 minutes for the PS to stabilize, then one by one powered up each of the other components.
And what do you know - the music's back, and the radio station is still gone. Seems it WAS position of the components - as Nkj suspected - that was the major culprit here. And Jim White's basic dictum - plug the Io directly into the wall - is vindicated.
I still have the chuff-chuff-chuff and hum to deal with, but everything I've listened to so far since this final change has been way more musical:
- Glenn Gould, Goldberg Variations (original Columbia ML 6-eye)
- Sibelius - Symphony No. 2 - Barbirolli (EMI UK colored postage stamp)
- Feeles - The Good Earth (Coyote/Twin Tone)
- Cat Stevens - Teaser and the Firecat (A&M brown label - prefer this to Island)
Will continue to report back. I have just the chuff-chuff-chuff and hum now.... in both speakers, slightly different sounding in each ... MUCH less annoying than the FM.
I think the next step will be to get the shielded umbilicals from Jim.
Thanks for everyone's patience during this typical audiophile journey, full of mistakes and wrong turnings but ultimately a happy ending... |
So Jim White from Aesthetix got back to me last night with some recommendations:
- swap tubes around to locate the "popping" tube (this has gone away for some reason - maybe it was an appliance in the apartment cycling on and off)
- plug the Io Sig into the ExactPower unit so long as I don't overload the EP with its 400W power draw. I think I'll be fine since I'm currently only using 250-300 watts of the 1300-watt max on the EP
- check to see that my phono cables are shielded; I know the Cardas are; I've written to Ikeda to find out if his is
- if this doesn't work, he can make up shielded power umbilicals for me (for the Aesthetix PS to the Io Sig) - the current ones are unshielded
- in other news, Cello is generously lending me some VersaLab Red Rollers to try
- and (always RTFM) I just realized that the ExactPower manual stresses the importance of locating the unit somewhere far from any preamps or any other components that carry low signals. Duh. I have it sitting next to the BAT linestage and not much further away from the Io itself.
Lots of stuff to try here, and, yes, I will continue to be reporting back. I also have to say, after 48 hours, that 72 dB on the Io Sig is making music sound much more beautiful - on both carts - than 80 dB. Ah.... gain matching. My favorite.
Patrick |
Hi Nkj!
I've lowered gain to 72 dB on the Io.... this is fine for both the 103R and the Helikon mono in my system.
Paradoxically though, I have to turn the volume higher on the linestage, which means that I can hear more of the chuff-chuff-chuff and radio station... even though I think the music actually sounds better, more natural and less overdriven.
So it's positioning, cables and tubes now...
Patrick |
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 |
A new clue!
I just realized that the RF noise has a soft "chuff-chuff-chuff-chuff-" sound to it, like a steam train but speeded up, as if something were cycling in and out.
This is more akin to very soft white noise and occurs at the same time as the radio station reception.
It is limited to the Io ... when I switch the input selector on the BAT linestage it vanishes.
Any ideas, anyone?
Patrick |
OK further updates... no response from Jim via email, I'm gonna try calling him next week. I love Aesthetix and they have been nothing but incredibly helpful when I've managed to get in touch with them. That said, and I know they are a small boutique firm, they could use a website with a FAQ and customer service email address which could get questions to Jim and back. (Even when you do call you usually have to leave a voicemail and get a call back.) All this said, I have to say that Aesthetix has handled every complaint and repair for me gratis aside from shipping the unit to them in California. My only problem with them is communication.
I've ordered Caig ProGold (which is now called DeOxit Gold) for the contacts.
Njk, I'm sure that positioning is a problem, since I only discovered this when I moved the entire system across the room to fire the speakers from the long wall. But as I'm sure you're all aware, it's a black art to arrange components regardless of their RF-susceptibility... right now the cables just reach from component to component. I don't have a rack, and all the components sit on amp-stands and footers which are directly on the floor - except the turntable, which sits on top of an (unused) subwoofer.
Add to this that the Io Sig is 2 heavy boxes... well, I guess I have to do it. Positioning is key. I'm just scared that I won't avoid the antenna effect without going all the way back across the room (and throwing out my back again!)
And then there's the cryotweaks recommendation from oldvinyl. I am trying everybody's suggestions, one by one.
Best
Patrick |
More news... the motor on my Garrard 301 is exposed in its skeletal plinth, and I thought this could be generating the problem. It has its own ground wire, unusually enough (I haven't seen this in other 301s), and I tried grounding it at the Io. No change.
Then I realized that I pick up the RF even when the TT isn't running, so it isn't the TT. It's the Io.
So next step is tube rolling in the Io, shielding the Io as suggested, rolling interconnects (currently balanced Kimber Select KS-1120 everywhere except from the two tonearms - Ikeda has its own single-ended pair, the Graham has singled-ended Golden Cross; noise is identical with either tonearm/cart).
In other news, I had my carpenter make me up a Graham/SME armboard so I could mount my 2.2 on the Garrard. It's currently running a Helikon Mono. Just roughed in alignment for now (though "roughing in" with a Graham is closer than most other arms) and making music.
Still just one phono stage with one set of inputs, so it's a task to switch between tonearms. But interesting. I might try mounting my as yet unused but intriguing Decca London Super Gold on the Graham, since it's said to like damped unipivots. (I have a Decca International Arm as well but would need to make a new mounting board once again.)
I still remain so impressed by the Denon 103R, which sits on my Ikeda. Maybe there's a synthesis between it, the Ikeda and the Orsonics headshell, but wow. For $250 (I just got an extra one) this cart blows away the Shelter. And it plays mono recordings more noisily than the Helikon Mono, but more musically. At nearly one-tenth the price.
sorry to ramble
currently on: Clara Haskil playing Schubert's posthumous sonata, mono, Dutch Philips Minigroove....... magical.
Patrick |
I had a similar problem with excessive RF with a phono stage I have since sold. You could here the music from the FM station through the speakers. I thought I had a $2500 tuner, but with no dial. In any case after several helpful pieces of advice from Audiogon members it turns out a major source of the RF was that the phono stage itslef was not properly grounded and eventually with a few tweaks to the chassis we ended up solving the issue. After getting rid of the FM station it turns out there was also an issue with hum, which was quickly resolved by moving the TT and phono stage closer to the floor.
It was almost enough to give up on vinyl, but the trial and error process was worth it in the end. |
.
Patrick,
.
I think Nkj has a good point about working to control RF.
.
I have some Versalab Red Rollers that are used on IC's for the purpose of handling RF issues. They have worked quite well in my system. You are more than welcome to borrow some to see if they help.
.
Email me off line and we can organize getting them shipped up to you.
.
Rgds,
Larry
. |
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 Cello,
It's funny, I was just wondering whether to post another update because it seemed maybe it was just me and Nkj at this point!
I got the shielded Belden AC cord for the Io and have exactly the same RF - so that's a no-go. (For those interested, it looks extremely similar to the stock cord, and didn't sound quite as nice - perhaps not broken in, perhaps other differences!)
I will be having an electrician in soon to find out whether my outlet is actually grounded at the circuit breaker box.
In the meantime, I'm investigating Telefunken (and other) 12AX7s / ECC83s. Man have the prices for NOS tubes gone up since I was last looking (about 3 years ago).
I just noticed oldvinyl's recommendation to use cryotweaks on the Io for RF rejection. I may try this too.
More updates as they come...
Patrick |
.
Patrick,
.
Please keep us updated with your progress. It is quite educational.
.
Thanks,
Larry
. |
Just ran a wire from the receptacle's ground screw to a new screw and hole I drilled in the conduit box. As before ratshack wire says there is now a ground.
I have a shielded supply AC cord on order as per your recommendation.
I think I will use an electrician for the next step!
In the meantime I will be searching for Telefunken 12AX7s to try in the Io's front end.
Thanks to everyone in this thread... audio's a journey...
Patrick |
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. |
Nkj: re opening up the main panel for a peek. I can unscrew the circuit-breaker main panel (it was done recently when I had some air conditioning wired installed) and look at the back of the switch which supplies power to the stereo. Is there any way I can tell whether it is properly grounded at the panel just by looking at it? Or would I have to measure continuity from the conduit sheathing to the switch (or the neutral wire)?
Don't worry - I'm an exceedingly cautious person - I won't do anything foolish. I've built a few electronic kits and rewired various electrical things around the house - lamps, light switches, and (as you know) receptacles, but I have not looked at the back of my circuit box.
Best
Patrick |
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. |
Just realized there's no point in swapping the EL-34s if swapping the power umbilicals makes no difference. And swapping the umbilicals makes no difference - the RF is more in the right channel.
I've just realized two things:
- moving the Io PS power cord around reduces the hum, but not the RF
- the RF problem and the hum may be in the Io tubes. I guess V1/V2 are the candidates for replacement. Perhaps I should try swapping the channel pairs first?
Patrick |
Thank Nkj. I just opened the receptacle and checked ground with the ratshack tester - and it is just as you describe - grounded when the receptacle is screwed into the conduit box, not when unplugged.
I was going to run a wire from the ground screw to the box as you also suggest, but my multimeter shows continiuty from the ground screw to the receptacle ends, which are firmly screwed to the conduit box anyway, so I don't see the point of a separate wire. Effectively, screwing the receptacle to the box grounds the box, as the ratshack tester shows.
Unfortunately I don't have the skills to check to see whether the conduit is firmly grounded to the circuit breaker box at the other end. It sound like I need to bring an electrician here, and in fact I have been considering a dedicated line for some time.
For now I'm going to replace the receptacle as it was (unless you really tell me a wire from the ground screw on the receptacle to a screw on the conduit box is somehow different from the (ground-continuous) receptacle-ends being firmly screwed onto the box).
Next I'm going to try swapping the Io's power umbilicals, and then the EL-34s, to see if that makes any difference.
I take your point about running the Io all-out in NYC. I probably could use the 72 db setting as well. But the 80 db setting sounds so good in my current system that I'm reluctant to switch.
I haven't been able to get in touch with Jim White yet - he's a hard man to get hold of!
Patrick |
