Thoughts on helping me trouble shoot a wido's syst

Hello all,

I have been helping a local widow try to get her deceased husband's system back up and running again. She is fairly local, but not just around the corner. Victor Khomenko of BAT put us together through a distress call on AA.

System is Quad ESL 63 speakers driven by Threshold S300 amp, CJ PV6 preamp, with several sources. The first visit I found a blown rail fuse in each channel of the Threshold amp. I replaced them and the rig was up and running again. However, I noted some static occasionally during playback, and recommended a tube change for the CJ preamp. I am not sure whether it was preamp tubes or the Quad speakers that were the cause of the static though, as I am unfamiliar with Quad speakers. They did sound very good aside from the static though.

Anyway, I am still waiting for the new tubes to come in when she e-mails me that the system went down again. I suspect the rail fuses blew again,as I noted from the paperwork that her late husband left behind that it looks like the rail fuses are an ongoing issue.

My question is this, for those more knowledgeable than myself (Al, hint, hint). I have heard that Quads present a difficult load, and that she is driving them through 40 foot runs of smaller gauge speaker cable from across the room. Now I do not know for sure if she has blown rail fuses again, but I suspect that she has. If she has blown rail fuses again, would you suspect that the long speaker cable runs could be the issue, or possibly she is not using proper sequencing when turning on/off her system? I'm thinking she may be turning her amp on first, and the CJ may have leaking coupling caps that may be leaking DC, so when she turns the preamp on after the amp is already on, she is blowing the fuses.

She says she is using proper sequencing, amp last thing on, first off, but when pressed about the importance, she cannot be totally certain of the order.

Anyway, bottom line, there could be many issues here, as far as I know. Quads may need service, long cable runs may be the issue, as might leaking caps from the CJ. Is there anyway to test the caps? What do you folks think the main cause would be?

I do plan on going back to replace the tubes when they come in, and will not be surprised to find more blown rail fuses when I do. I am pretty busy, and can't afford to go running over to her house on a regular basis, but I want to help as much as I can. Is there anyway to test the output of the CJ for leaky caps for DC with a DMM? How about anyway to check the Quads? I have very little experience trouble shooting electrostatic speakers.

Thanks all for your feedback.

I have always been of the "start easy and work your way up " camp. Yes replace all tubes, These long speaker runs are the problem im sure...And probably AL would agree, The long runs impose a bad resistance that the amp and speakers don't like. I would start there , Shorten the speaker wires or get long IC's and place the amp much closer to the speakers. Good luck I hope you work it out, sounds like a really nice system.
Jm, feel lucky that it all didn't blow up! All really nice gear but older and tempermental. I would have brought the pre up on a variac first.

It's very likely the CJ needs some minor work. When Thresholds blow, they really go. If you blew the fuses once already, you should be using a different amp that you are sure is working until this one can be checked out. It's almost always worth repairing a Threshold but not always worth rebuilding one that blew up.

Since you have said that you are not a pro, my solution would be to have the CJ bench tested first. While it's there, have the Threshold checked out too. If you have a cheap receiver, try out the Quads at low levels to make sure they work fine-don't push the volume. Finally, use a source that won't give you headaches. Either a cd player or even mp3 with very clean music only.
It does sound like the long cable runs would be the problem here.

My suggestion would be to convince her to downsize into something simpler and reliable. My 2 cents.
When you have failing panels on Quad's static can be heard intermittently when playing music. Had to have mine repaired when they did this. My guess is either a bad tube or Quad. Does it come from both channels? If only one channel, switch the left and right speaker cables. If it stays in the same side it is the Quad. I hope this helps.
Can you define "smaller gauge"? If it is really small (e.g., zip cord) I would try a single or double run of 10 or 12 gauge Romex to see if that solves the fuse blowing problem. That will be a cheap test and the Romex can be used for something else if they don't sound good. With respect to longer interconnects, that's a great idea IF you use balanced connections. The speaker wires are 40 feet so interconnects are probably going to be comparable. If I recall correctly, the CJ uses only single ended, correct? If so a long run of interconnect will introduce its own issues.
I don't believe that the Threshold amp would have any difficulty driving those speakers and cables. It keeps blowing rail fuses. Have you looked at the amp. There may be a problem with the internal circuitry of the amp. The output transistors and mica insulators may be shorting intermittently. First, use a different powerful amp and see if the problem goes away. if it does, it is the Threshold. I would then remove and test all the output transistors and mica insulators and heat sink compound. Also, I typically replace the output transistors with new Motorola MJ21193 and 21194 transistors and the drivers with MJE 15023 and 15024 transistors. Much more linear and much better sounding. Easy to do on Threshold amps. Just me, but I don't think it is the pre-amp. Could be, but I'm not sure. Fuses blow for a reason. simply replacing them does not diagnose and fix the problem of the device.
Thanks for the replies so far. To answer some questions, by smaller gauge I'm guessing 16 gauge or maybe 14 gauge tops. I also agree that this system is too much work for this woman. I did try to suggest moving to something simpler last time there, because working on this system is very difficult, and yes, the gear is older and has high maintenance history. She doesn't seem interested in changing anything, as when this system plays it brings back many memories of good times she had with her late husband.

I do not have time or energy to take all of her components and ship them out for proper repair/inspection. She doesn't seem inclined to pay for expensive repairs either. Bottom line is that I got dragged into a bad situation. I was told that there was probably just something unplugged or a switch turned off, but it has turned out to be much more than that. I ordered the tubes for her, and when they arrive I will go over again and replace the tubes and check the fuses. I will suggest that she have her system professionally looked at, but I have no recommendation for her.

It's a bad situation. He left her with a high maintenance system that she desperately wants to use but does not have any idea how to maintain. She is a nice woman, and I don't want to hang her out to dry, but I can't donate the rest of my life to maintaining her audio system, it has too many needs.

Perhaps someone else in the Southeastern part of Pennsylvania with more knowledge, time, and money than I have can be of assistance to her.

Maybe I will suggest that she just leave her system on all the time, since it seems that most of her issues flare up when turning the system on and off. Thanks again, sorry for just thinking out loud here.

So far the variety of responses are what I expected and feared. Some think preamp, some amp, some speakers. Thanks anyway fellas.

John, thanks for the nice word, and more importantly, kudos for undertaking this effort.

I once owned an S300, and I can tell you that it takes, IIRC, something like 45 seconds and perhaps more for it to completely stop functioning after it is turned off. So my guess is that even though she may be turning the amp on last and off first, she may not be waiting long enough after turning the amp off before she turns off the preamp. If so, what is blowing the rail fuses may simply be a normal turnoff transient from the preamp, its effects perhaps being exacerbated by the capacitive nature of the speaker's impedance at many frequencies. Or perhaps by a somewhat abnormal transient, due to degraded capacitors or whatever, that would not be much more than a minor sonic issue otherwise.

Also, I can tell you that my particular example of that amp, which I bought used, had a wicked low frequency turnoff transient itself, which occurred at that 45 second point. (Some other S300 owners I once asked reported no such symptom, but perhaps it is something that sometimes tends to happen with older S300's). The transient didn't bother the speakers I was using at the time, because they could handle 200 watts or more comfortably, but I wouldn't be surprised if that transient would have damaged an ESL-63. The ESL-63's power handling specs are indicated here in Stereophile's review.

As far as the speaker cables are concerned, I agree with Minorl. I would certainly expect the resistance and inductance of the cables to have at least minor effects on sonics (given the speaker's impedance curve), but I can't see how they would have anything to do with functional issues or reliability. And while the capacitance of a 40 foot run of some speaker cables could conceivably result in blown fuses or worse with some amplifiers, especially in combination with the capacitive nature of the speaker's impedance, I wouldn't expect that to be the case with an S300. Assuming, that is, that she is not using those few cables which have ultra-high capacitance, such as Goertz or the old Polk Cobras. And I doubt that she is using either of those, as Goertz is fairly heavy gauge, and IIRC Polk Cobra is flat and about a half-inch wide, and has a distinctive mottled appearance.

Regarding checking for DC at the preamp outputs with a DMM, if significant DC were measured it would certainly indicate that there is a problem, but I'm not sure that a reading of negligible DC would be conclusive of anything, given the possibility of transients.

And I agree, of course, that replacing the preamp tubes does seem like a very logical step at this point.

Hope that helps. All best regards,
-- Al
Thank you for the tip Al, I will talk to her about lengthening the time between power up/down, even when using proper sequencing. I still think she would be better off leaving the system on 24/7, and I will address that subject too, though I'm sure she probably won't want to do that.

John, it looks like you are in a tough spot. You should find a local repair shop that does house calls. Give her the name/s and tell her that without proper care this system is just going to keep blowing up. Install the tubes and walk away with a sincere apology.
Well I stopped by today and put in a fresh set of tubes. No dice, no change. The volume level is still very low and distorted. My first visit there was no sound at all, when I changed the blown rail fuses in each channel of the amp the sound came on as normal. It sounded pretty good aside from some occasional static.

Now I'm guessing after sitting dormant for over 5 years, that little bit of excitement was just too much for some of the capacitors, and they gave up the ghost. At this point I do not know if it is the preamp, amp or speakers that are at fault, and I do not have the time or energy to continue to fight her battle for her. Her son doesn't seem to care.

She asked me if I could sell the gear for her, she said she would split the profits 50/50. I have never sold questionable gear before though, I would not even know where to start. How do you sell something if you do not know if it works or not? I was thinking of calling a couple of local dealers, who may or may not be interested. I told her that she may get very little money, if anything at all for the gear.

I don't really want any money, but I don't want to waste any more of my time on her audio system either. My life is hectic enough as it is right now. I just want this to end.

John, I can't back you technically, just morally. It sometimes seems like a down-hill battle in taking the righteous path.
You are the Victor even though her system will not surrender.
The best way to sell the gear is via ebay. Just give an honest description and make sure the buyer knows what they're getting before payment is made.
If you remove it from her place you can test each piece individually and maybe determine the faulty component. Good luck to you.