Condo Power Issues

[KeithR]

Hey guys- need some help. Here is the background on my potential power issues- I seem to have an issue blowing tubes and fuses and am now wondering if it's related to my condo.

I installed a dedicated 20A line to my living room years ago. I run two speakers (active subs), a 60" Pioneer Kuro, 2 small monoblocks, a preamp, dac, and two sources off this same line. I use TrippLite surge protectors (2).

I have never had problems with SS amplifiers (Pass, FirstWatt, Onkyo, etc). However, my BAT 75SE blew one set of fuses back in 2005, but overall was pretty stable over 2 years. In 2011, I had a pair of Sophia amps in on demo and in a week, one just refused to power up. Turned out to be a B+ issue in the amplifier and the manufacturer said the amps weren't ready for primetime. Fast forward to 2012, my Quads blew a transformer last summer (the heating filament or something). I purchased a Almarro 318B integrated and had no problems for several months. After that, I had a Vac Phi Beta---which blew a fuse (1 of 10 in the power supply, so very robust build) as well as had a "runaway" tube---which unusually, actually smoked two KT88s at the same time. New tubes and the Vac hummed right along. I sold the Vac ultimately for sonic reasons. My Quads 2 40s are back in my system and just blew a rectifier (274B) and now won't give me any sound even with stock rectifiers---they heat up, but no output, so I've been told by a friend the issue is in the B+ and he is stopping by tomorrow to open them up.

We've tested my voltage at the wall with a voltmeter and it was 120. I have not called my power company, but am thinking about it. I have never had a source component, preamp, or SS amp have one issue in the past 10 years on the same outlet.

I think there is too much room for chance in this situation and that I must have a power issue with high voltage amps--I have thought about a PC in the past, but haven't done it because 2k isn't an inexpensive solution and I'm puzzled why these issues are occurring. I'm pretty much reached my limit and may just go back to SS amplification.

Look to the forum for some much needed guidance.

Happy Monday,

KeithR

 

[cjfrbw]

Can't really help, but to agree that there must be a power problem for that many fuses to blow. Our little place in Santa Cruz has very dodgy power, but nary a problem with any of the amps or electricity in nearly three years.

Frantz is one of the resident experts in power conditioning and power grids here, maybe he could weigh in.

 

[mep]

I think your first clue is that you have never had a problem with SS amps.

 

[KeithR]

I think your first clue is that you have never had a problem with SS amps.

well because they are low voltage is my guess. i'm either snakebitten in the past year, or there is something going on.

the Quads sound better on my speakers than any ss amp i've had...and that includes some great ones

 

[mep]

Which Quads?

 

[KeithR]

II 40s, so KT-88 based. It's a really simple circuit which makes this even more unusual I'd think.

I should qualify that as "ss amp I've tried on my speakers"- that includes Mac 601s, FirstWatt SIT1&2, BAT 300xSE, etc. I owned the Pass X250.5, but not on my current speakers.

 

[stargate]

keep checking your voltage you could have transformer dipping from outside..could you tell me how old is the transformer and what size kva?

 

[Speedskater]

Do you live in the US?
If so get on of those little Kill-a-Watt meters.
Check several of your AC circuits from time to time.
At any given time do the all read about the same voltage?
Rather than some being way high and others being way low.

 

[DonH50]

SS is usually at least as sensitive as tube amps IMO. I have always found tube gear in general a little more finicky and less reliable, although others have had fewer issues. Your description of your trials and tribulations seem somewhat uncorrelated so I am not at all sure I would point the finger at power. However, if you suspect a problem, your local power company might install a monitoring device for free or very nominal charge to see what happens over the course of a week or so. It is also possible something else is causing power issues, like the HVAC unit, and coupling through the main service to your audio outlets.

 

[DaveyF]

Keith, while I LOVE your Pioneer Kuro, it is a REAL power suck! Were you having the same problems when the Kuro was not in use??

 

[KeithR]

The BAT was before the Pioneer and I blew one set of fuses, but interesting point.

 

[KeithR]

keep checking your voltage you could have transformer dipping from outside..could you tell me how old is the transformer and what size kva?

I have a request into the power company and will get this information

 

[treitz3]

Hello, Keith. I'm sorry to hear of your issues. That's gotta be frustrating. What I would suggest is to have the power company put on a 24-48 hour recorder that will prove both to you and the power company that your voltage is or is not stable over a period of time. To rely on a single reading or even multiple readings may not reveal what's going on. Just based off of your symptoms, my guess is that your condo is experiencing fluctuating voltage. That might explain why tubes are giving you issues more so than SS amps.

The issue may not be at your transformer. It could be miles down the road at a substation. Just keep on it because this will cause other issues, costly issues. Hot tub motor failures, refrigerators expiring before the end of their useful life, A/C units going bad and other things beyond what you are experiencing just within your household.

Tom

 

[KeithR]

Thanks Tom, that does seem like the best option and I hope to hear from LADWP soon.

Perhaps Frantz can chime in here as well?

 

[FrantzM]

Hi Keith

Treitz advice is very good. Back a few years maybe 10~15 years, I believe Radio Shack had an inexpensive Power Quality logger/Analyzer. You would plug it in an outlet and it will give you a basic reports. It's no longer in their catalog.
I believe you are suffering from sags, which is when the AC voltage goes down for an amount of time ranging from a few cycles ( n/60 sec) to sometimes minute.. When the sag goes for a longer period of times several minutes it is often called a brownout .. both can blow fuse in equipment. There is also the phenomenon known as swell in which the voltage goes up for a few cycles to a few mins .. Both blow fuses and more.

Power companies sometimes conduct power audit at the customer request. It is good to tell them that you suspect power quality issues. PQ analyzers are usually expensive ranging from about for the lone of he least expensive I know of (can't get the name but about $500) to well over $20K.. They can be rented though there is a place in California Summit Technologies 408 982 9280 that rent them. Call them and ask for a simple model that would just plug into an outlet. This is all the monitoring you need truly : from an outlet.
Last but least be gentle with the power company, the issue may emanate from your own house/condo. There may be some equipment with unusual (or out of specs) current draw or Power Factor at start-up .. AC and refrigerators compressors, in general electric motors are often guilty of such, things like washing machine, dishwashers, sump pumps, etc. Often a leaking starting capacitor can create all kind of problem. A Power Quality audit will certainly show these up .. The cause may not lie within their network however.

I will not recite my PQ litany

 

[DonH50]

SS is usually at least as sensitive as tube amps IMO. I have always found tube gear in general a little more finicky and less reliable, although others have had fewer issues. Your description of your trials and tribulations seem somewhat uncorrelated so I am not at all sure I would point the finger at power. However, if you suspect a problem, your local power company might install a monitoring device for free or very nominal charge to see what happens over the course of a week or so. It is also possible something else is causing power issues, like the HVAC unit, and coupling through the main service to your audio outlets.

Jez' sayin'... At least we have a consensus! I suspect short-term brown-outs or even very brief glitches (interruptions) are at fault. A brief glitch can cause all sorts of havoc in the power supply and thus everything else in a component.

 

[KeithR]

Update---the internal fuses in the amp blew and the amps work again once replaced. The question still is what blew the rectifier and the fuses. The amps power consumption is 180va each, so 360va total.

I spoke with DWP and they have a long back log to have a test to the building (they don't cover to the condo itself). Apparently my transformer is right behind my building- and is 100kva for the 12 unit dwelling. They did not know how old it was. He said I was the first complaint, so likely nothing wrong from the source.

 

[KeithR]

I can also buy a used Monster voltage stabilizer for 500 bucks - would that be a solution?

 

[KeithR]

I also called California Summit, Frantz- a one week rental costs $400. Yikes.

 

[FrantzM]

So a small update---the internal fuses in the amp blew and the amps work again once replaced. The question still is what blew the rectifier and the fuses. I am following up with LADWP this afternoon.

Also went to the breaker box and made sure nothing else was on my dedicated line (like recessed lights)- confirmed it is just my audio system and Pioneer Kuro.

Huh... This is one of those things that usually come as a surprise. Your "dedicated" line shares the same AC as your HVAC. The only dedication that those so called "dedicated" lines have is their own breaker; else they share the same input as many other stuff in the house...including HVAC, Washer, Fridge etc ... Those appliances/components affect the AC in your "dedicated" lines.

===========|Breaker 1|
AC Input------|Breaker 2|
===========|Breaker 3|
===========|"Dedicated" Line 1 Breaker |
===========|"Dedicated" Line 2 Breaker |
===========|HVAC Breaker|

Disturbance from the other breakers circuit will find their way in your "dedicated" line. To me the very best is Double conversation UPS. I have made that abundantly clear. In the absence an isolation transformer of sufficient rating can work extremely well. Proper grounding to provide good out path to noise is a good way to start. In the short term and because this is a condo which makes difficult solutions like Isolation transformers and Double conversations UPS .. You absolutely need to talk to your power utility.

Just read your last posts. I am not sure the $500 Voltage regulator will do much good. Their top of the line is $1700 or so, I don't know much about it. I also find the price of the rental brutal. It might be a good investment in regard of the price of repair of your gears and if the power company doesn't help.
I don't know the full current draw of your system. The PS Audio could be a solution . It is a regenerator after all. I don't know if it has batteries or how it deals with brownouts tough. Will look int o that and post back.

P.S. was having problems withthe little schematics above. Solved now I see