Bill, is the static you are describing the kind that pulls at you when you remove the LP, or static in the sound?
How long have you had these components, and / or what have you changed lately? |
Hi Albert,
I've had the Rockport about a month and the Aesthetix just a little longer, but there have been a few problems with the Aesthetix in shipping and it's been back to California twice.
The static is transient almost line static which occurs whether there is a record playing or not. It's a slight pop-crackle which doesn't occur when the Aesthetix is just warming up. It's not as pronounced a pop as record pop, it's more a creckle. I try touching everything and it doesn't eliminate it or creat it.
Any thoughts?
Bill E. |
Do you have a spare set of tubes to try? Is it both channels? Or just one? |
I have been told that in spite of the reputation and high quality of the Caddock resistors chosen for the Io, some of these have mechanical failure that causes noise and microphonics. They are the large black resistors near each group of tubes. You can try tapping them with a NON conductive tool to see if there is a reaction.
Be extremely careful touching things inside the Io. There are two supplies that together measure near 1100 volts ! I would very much like to keep seeing your posts here at Audiogon.
It the noise equal on both channels or limited to one? |
One more thing Bill. Even if the Rockport is turned off, the motor controller stays on all the time ( I think ). Do you have the one built by Rowland? If so, you might use a VOM to measure the output or chassis to ground and be sure there is not a leaking cap in the circuit.
Is the air supply pump for the Rockport on the same circuit with the other gear? |
Bill, my first thought would be to use the basic testing methods we would use with any component. First unplug the entire phono rig from your preamp, and see if there is any change. If it goes away, the problem is somewhere before the preamp. If it doesn't, then it is in the preamp or after. Assuming the problem went away, plug in just the IO without the turntable. If problem shows, then check the IO by swap-out. Being a dealer, you must have some other phono section around somewhere. Swap out the IO for another phono section and see if the sound goes away. If it does, then you know it's in the IO. If not, then continue the process back to the turntable, with the swap-out method. Obviously, you can't swap out for a new Rockport, but if everything else checks out, you may have to just plug in some other turntable to see if that does it. With new equipment, once you have isolated the problem down to the offending item, then have it replaced by the manufacturer under warranty. |
Likely the Io and if in both channels it is probably a power supply tube unless you are running two supplies as Albert does.....It sure wouldn't hurt to get the ICs up off the floor either.....I used to have four Rockports in my neighborhood including two similar to the System II Sirius and nobody has complained of static problems..... |
Bill- Do the problems ever end! Makes you wonder if it would be easier and cheaper to maintain the 512tr!!! Though I suppose you couldn't use that when its snowing ;) If you get the bugs out of your rig I am sure you will need to find something else that is systamtically problem prone, its always a challenge to over come! ~Tim |
I'm embarrased to say that I'm having a hard time recreating the problem. Mike Lavigne reminded me that the platter is not conductive so that every time I take a record off it builds up static in the Rockport. Also, he suggested that the central ac may be creating some line static when it cycles on.
I'm going to take a lot more time listening and do my best to isolate the issue.
I'll try your recommendations and get back to this thread as soon as I know more.
Bill E. |
Hi,
Looks like by having 2 ground bar, you created a ground loop. Try to use single ground for audio gear.
Using a silver-based ground wire helps tremendously, especially if you can find an 8ga silver litz wire for ground.
Silver plated ground bar helps further. Common Home Depot ground bar may be zinc plated and
have dielectric effect. |
Bill, you wouldn't want me to come over with my Aloia preamp w/phono stage now, would you? (if you don't tell Andy, I won't ;~). Although I'm not up-to-date with your wiring scheme, I thought that you had planned a dedicated (supplementary) earth ground for the system, via the dedicated circuit box - the AC should not be an issue if you've got this. I believe Extremephono has a point about possible ground loops - one pole in the ground is enough.
As you haven't mentioned any problems with playback via the AAC-II, your efforts should concentrate on the IO --- power supply vs. grounding scheme.
Good luck, and be careful if you go poking around (I mean in the IO unit).
Arooj |
I've been through a series of trials and it seems that the TT produces static on removal of the record because it's an air bearing under the platter and the tonearm is an air bearing.
In addition the phono stage is making funny ripping like crackling noises which appear to be static mostly from the left channel. There are some pops which seem to be record hiss and pop, but the strange sound is intermittent but occurs a number of times per minute. It appears to start after the unit is warmed up for a few minutes.
There were strange transient noises yesterday and I learned that Aesthetix IO's with two power supplies like to be separated by a lot of air. So, I moved the power supply from the middle shelf to an amp stand to the right of the turntable and they have not returned. It probably didn't help that it was about 100 outside yesterday and the Tenors and the Aesthetix don't really help the temperature in the audio room.
I swapped five of the nine tubes on each side and the noise still comes from the left channel.
When I disconnect the TT the noise is the same and when I disconnect the IO from the Tenors it disappears.
What is the problem?
I don't know.
Bill E. |
Bill, it seems to me like it is a leaky cap, possibly in the power supply of the IO. I don't know the layout of the IO, but since it has dual power supplies, can you switch the left power supply module to the right and see if the noise changes to the right channel? This might isolate it to either the power supply or the audio section. If you can pin it down to one, or the other, it will identify the item to replace.A cap problem would occur sometimes after warmup. If it were mine, I would return it under warranty. This is too expensive an item to be playing around with, and they should be happy to let you have a replacement for your new item and let them worry about fixing the problem. Their reputation is on the line, and I doubt that they want any questionable units floating around in the hands of unsatified customers. If you bought the IO second hand, then have the factory or your technician check it out. I think that isolating the problem as best you can is all you can or should do, and then let a repair professional handle it from there. I hope this helps you. |
