Never let your speakers wash the dishes. (Sorry, could not resist. It's a matter of syntax.)
Seriously, it would help to know WHICH resistors are failing and whether in all 3 cases the failed resistors have a common function. For example, is it the phono load resistor for the R channel that is failing in all cases? You should be able to get that information from the guy who does your repairs. Also, in all cases, were you correct in visually identifying failed resistors; you tell us that this or that resistor looked like it was blown, but I wonder just what the problem(s) actually were. If a resistor blows, you usually think it was passing too much current, which increased the power handling required above the resistor rating (in Watts) and overloaded the resistor. Since the phono load resistor handles only a tiny current, many times the builder will use resistors with a very low power rating, which is easily exceeded. But not much can happen in that position in a phono circuit that would lead to that kind of failure. It's puzzling. But, if it's always the phono load resistor, that at least would narrow one's thinking.
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Hi lewm
Yes at least if I was washing dishes with them that would explain things!
I'm going to take everything to my repair guy and ask him to assess. I will repost with that information. I'm certain something is blown as one of the little "resistors" it's definitely burnt and there was smoke....as for it actually being a "resistor" admittedly this is what I determined from an intense session of Googling.
Again, perhaps my system simply needs an exorcism... |
As the late great Roseanne Rosannadana said, “It’s always something.” |
As an update, my dealer is as well perplexed and will ask one of the VPI owners for an opinion.
In the meantime, the entire system is going on hiatus until I am sure that nothing else will be damaged. |
I am forgetting the fine details of your story. Is this problem occurring always with the same cartridge and the same wiring from cartridge to phono input? If so, I am wondering whether you are experiencing an intermittent short between the hot and ground on the right channel of your cartridge or anywhere in the wiring up to the phono input. Why this would blow the load resistor, I have not yet worked out,But it would not be good for the gain device that comes at the input. Intermittent wiring failures are very difficult to find, for the very reason that they are intermittent and may not be in effect when troubleshooting. |
I would wonder about some out of band signal overloading the right channel. It is a phono stage and expected to amplify very low level signals. But why always the right channel? Both channels share the same immediate environment. Maybe we are looking in the wrong direction. A problem with the integrated makes more sense I think. Something is overloading the right channel input. You need the tech to hook the inputs of the integrated up to a scope. The internal phono stage shares the same line level bus. |
Shorting the grid of a tube or the gate of a transistor to ground would eventually blow the device. Could be anywhere from cartridge itself to phono input. Because this problem has recurred with three different phono stages, that tends to make me think the problem is extraneous to the phono stage. What do you mean by an out of band signal? Are you talking about R FI? Then you’d have to think why is it only affecting the right channel? |
I would get rid of that table/arm/cartridge unless perhaps VPI is ready to take a serious look at it right away. This is becoming a nightmare. |
Thank you very much for your input. I am bringing ALL of my equipment to my tech on Friday (he can't look at it until then), but I share your concern about intermittent issues. What if everything checks out ok? Do I dare plug in and try again?
Again, all other components were used daily without issue (everything is offline now until this is sorted).
Just to be on the safe side, I will try and return table and cartridge. I harbor no hopes that if it is the TT that I will be compensated for my phono losses - but best to start from scratch. Process of elimination. I know it is not my phono. Next replace the TT/cart. Next the amplifier. I am also having an electrician inspect our electrical to rule out this being the culprit, although I am doubtful that is the issue as I have a Furman power line to protect against surges.
Lastly, the exorcism I mentioned. |
@lewm
Lew,
Could it be an RF spike from the TT/cartridge/cabling.
Years ago I had a taxi driver on his RT outside my house just about turn my Apogee panels inside inside out. Nothing blew though.
@mijostyn might have a point, If the integrated linestage is presenting a short on phono, what does that do for the phono stages.
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Based on the very limited information, I have the impression that the failure is occurring somewhere at the phono stage input, if for no other reason than the fact that the OP needs to play a record in order for something to blow. Because apparently the same failure has occurred with 3 different phono stages, that indicts something upstream from the phono stage, anything right up to the input to phono. So I guessed that there may be an intermittent hot to ground short on the R channel input upstream from the phono input. But now I think of it more, that would just be like a mute switch. Signal would disappear but no damage necessarily. Seems like you are thinking about something on the phono output side, between phono and linestage. Again, given the limited info, that certainly is possible. RFI doing this seems far-fetched; RFI can sure mess up listening pleasure but does not normally destroy audio components. We'll probably never know. |
Just as a continuation of the previous discussion. I do happen to live near a fire station, and also noted some RFI just prior to these events happening. I have brought it to the most experienced person I know of, and he has a technician in House as well. Their theory right now is that there may have been static discharge, and with the VPI arm using a unipivot design there may be grounding issues. However, there are no other reported similar incidents with this type of table as it is a very popular and well respected table so still no explanation as to why I am continually losing phono stages. If this information is helpful, when the technician examined the avid phono, the right channel was affected. That is 3 right-sided channels on 3 phonos damaged.
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@slashsmil
I would borrow another integrated amplifier if possible, and try running for it a week. If you can eliminate the amplifier it will narrow down the cause to the front end.
After that if it still occurs, try another cartridge if you have a spare or can borrow one.
This will further narrow down the cause.
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Good morning,
From the damage done my most recently impacted phono stage, and given the damage to the other two it looks like static discharge is the culprit. As well, looking on forums from other VPI owners, it seems that battling with static is not unusual. There is another post on a forum with exactly the same problem.. three phono stages damaged to due to static discharged. High-end equipment including a Sutherland phono.
My dealer has agreed to take back the table and cartridge. I will be getting another brand turntable, I would not be confident to ever plug the VPI in again.
Thank you very kindly for the responses. I am hopeful as well that should someone have similar issues with their VPI table, that this post would be helpful. Certainly this issue tested my sanity!
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Out of band signals can certainly overload amplification circuits if they are broadband enough. My point is, what is a turntable, tonearm, cartridge going to do to torch the right channel of three different phono stages. Shorting the input is not going to hurt anything. I think something is happening at the output of the phono stage on the right channel. The OP will have his equipment checked out and let us know but I would bet $100
the problem is in the integrated. So, don't sell your turntable yet!! Wait until the integrated is gone over.
Lewm, I would bet the phono stage is disconnected from the line stage when it is not selected so, it is isolated until it is selected. |
Mijo, And....?
I think the static discharge hypothesis makes some sense here. But why the turntable is uniquely held responsible, I do not know. I don’t know how a turntable, especially a belt drive turntable with an outboard motor that is displaced from the phono pick up could likely be the cause. Static discharge can be a local phenomenon, really having nothing to do with the equipment.As to the idea that the downstream component is complicit in this problem, please give me an idea how that could be. Then I will believe in it more avidly. |
It just occurred to me that solid-state devices are more susceptible to static discharge than are tubes, as a rule. If I read the OP correctly, all three phono stages that have failed are solid state. It might be interesting to try a tube-based phono stage as a replacement. Of course, as well, one should do an analysis for the source of a potential static discharge. |
Hi everyone thank you for your advice. The integrated checked out flawlessly... and continues to work with my other components without issue. I thought perhaps a bad channel on my amplifier, but the channels used were different for each phono stage. Yes, solid state all of them.
A similar issue was also posted by another VPI owner on another forum....
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I just purchased an Allnic h1201, I am gunshy about connecting this.
The turntable is likely to go back as I just purchased it new, and all of my troubles began when it arrived.
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Just as a follow-up to my tale of woe. Graham at the Electronic Depot in Niagara Falls has been a class act. He has agreed to take the turntable and cartridge back. Full refund. He has even agreed to pay for the shipping.
I have just put a deposit down on a Technics 1210GAE. Just deciding on the cartridge now…!
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I am not familiar with the design of the VPI Prime, but the problem seems more likely (than static discharge) to be some intermittent contact between the right channel ground and an AC hot chassis.
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Static discharge blew the right channel 3 times. I find that highly unlikely |
Very interesting. Two stories exactly the same can't be a coincidence. "Turntables Electrocute Phono Stages!" Only VPI could manage to pull that one off. Never was a fan. The "no anti skate" routine turned me right off along with the unipivot tonearm bearing.
@slashsmil, Have you decided on a cartridge yet?? |
Indeed.. I found a very good deal on an orto Cadenza bronze.
I’ve been very fortunate. The retailer who sold me my phono card for my integrated was kind enough to credit me back after it was damaged. I put the credit toward the orto and even then he gave me an additional 10% discount. Ended up coming in about 30% cheaper than retail. Just have to wait for it to arrive... The table though arrived it is gorgeous! I am very much liking the black color.
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