Household electrical problem

[Irvrobinson]

Irv – thanks for your comments on the Quad 909 design. A recommendation from both you and TLS Guy is worth something. Any suggestion of a good price to bid?

I would just buy it now for $950. Assuming the ad is correct, that it only has 16 hours on it in mint condition with the factory box, that's a good price.

 

[Swerd]

No, the Quad current dumping amps do not fit the usual A/B description.…

Thanks! Any suggestion on a price I might bid? Or do you think $950 plus ~$30 shipping is good?

I assume you believe this amp would be stable driving a pair of Salk Veracity ST speakers. They are MTM speakers with two SEAS W16 woofers and one RAAL ribbon tweeter. They are said to be 4 ohms impedance at the lowest and average at 6 ohms or higher.

So crack of dawn Saturday I'm dragging him to http://katiescarsandcoffee.com/ to check out the exotic wheels there. Then back to the Swerd lair for furniture moving, amp hoisting, general trial and error to figure this out. Perhaps we should start a poll as to what the mysterious trouble is. I'm in for a bizarre wiring setup when the house was built and a single failure in the power to those two outlet halves but we shall see...

Are you coming to pick me up Saturday? Maybe I'll suffer to get up that early.

If you've read above, I've got most of the initial work done. The AC outlets are all OK, but the amp may be belly up. But I do have 1 or 2 other wiring projects that need two pairs of hands. So, I'd still appreciate your help.

Aren't you going to tell anyone about your semi-new wheels?

 

[Irvrobinson]

I assume you believe this amp would be stable driving a pair of Salk Veracity ST speakers. They are MTM speakers with two SEAS W16 woofers and one RAAL ribbon tweeter. They are said to be 4 ohms impedance at the lowest and average at 6 ohms or higher.

This amp will be half asleep with a load like that.

 

[TLS Guy]

@Johnny2Bad, @Alex2507, @KEW, @TLS Guy, @Irvrobinson, @Dan and all others still interested.

I pulled out the amp this afternoon.

• It was not plugged into an AC outlet behind the cabinet, but an accessible outlet off to the side. I'm smarter than I give myself credit for or can remember. Both outlets of the duplex (tested by both items shown below) were good.
  
  
  
  
  
• The amp's removable AC power cord appears to be working. When it was plugged into the outlet, I used the non-contact voltage test pen, it beeped and showed red, indicating voltage at the amp end of the cord. I inspected behind the cabinet with a flashlight, and I saw no sign of dead mouse (mice).
• So, that leaves the fuse and the amp. The initial symptom, after switching the amp on, was no sound came from the speakers, and the red LED above the amp's power switch did not come on. That suggests the amp's power supply is the problem.
• I'll get some fuses next, but if the fuse had failed, it suggests an internal problem. The fuse 12A Slow Blow, 250 V, ceramic not glass, is 30 mm long. It appears to be polarized with a red stripe around one end and a black stripe at the other. Of course, I pulled it out without noticing which color was at what end. Does anyone know if this matters?
  
• For what it's worth, the tag on the back of the amp says 900 W and 64U (anyone know what 64U means?). The manual said 650 W. I'm inclined to believe the bigger number is correct.
  
• This amp is 19 to 24 years old. I bought it used in 2008, for $400 plus shipping. Unfortunately B&K is out of business. I wonder what it might cost for local repair?

Irv – thanks for your comments on the Quad 909 design. A recommendation from both you and TLS Guy is worth something. Any suggestion of a good price to bid?

For a 909 in that condition, the buy it now price is excellent value. If you let the bid go it will probably go up to $1200 or higher. For that amp $1200 would not be excessive.

 

[KEW]

Input watts (drawn from the AC line) and output watts (measured at the loudspeaker output terminals) are not the same thing. Although there is a relationship, output watts should always be higher than the power drawn from the AC line in watts. The exact amount depends on the power supply and amplifier's overall efficiency, so there is limited value in comparing the two.

Are you sure about that? Because every amp I have ever seen specs on defies that statement. I already gave info on the Niles SI-275. My Outlaw M200 mono-block draws 600 Watts and produce 200W RMS @ 8 and 300W RMS @ 4 ohms.
I could see how with capacitors you might produce a short term wattage in excess of the input (though I don't know that is possible), but RMS watts are sustained.

 

[KEW]

• For what it's worth, the tag on the back of the amp says 900 W and 64U (anyone know what 64U means?). The manual said 650 W. I'm inclined to believe the bigger number is correct.

That is still too efficient to be consistent with the amps I have looked at, but it is probably not RMS watts.

On the Monolith/ATI question:
It seems to be an ATI model AT1807 without the balanced connections.
Read the introductory paragraphs here:
http://hometheaterreview.com/monoprice-monolith-7-seven-channel-amplifier-reviewed/

For me, the real clincher is:

the Monolith 7 is "designed, engineered, tested and assembled in the USA,"

Not many companies assemble electronics in the USA!

 

[KEW]

More discussion of the Monolith, if you are interested:
http://forums.audioholics.com/forums/threads/monoprice-monolith-7.103697/

 

[TLS Guy]

Thanks! Any suggestion on a price I might bid? Or do you think $950 plus ~$30 shipping is good?

I assume you believe this amp would be stable driving a pair of Salk Veracity ST speakers. They are MTM speakers with two SEAS W16 woofers and one RAAL ribbon tweeter. They are said to be 4 ohms impedance at the lowest and average at 6 ohms or higher.
Are you coming to pick me up Saturday? Maybe I'll suffer to get up that early.

If you've read above, I've got most of the initial work done. The AC outlets are all OK, but the amp may be belly up. But I do have 1 or 2 other wiring projects that need two pairs of hands. So, I'd still appreciate your help.

Aren't you going to tell anyone about your semi-new wheels?

Swerd, I strongly recommend you purchase that 909 ASAP. It is a much better amp then the one you have. I own 9 of those amps.

Seven power the studio.

Three of those are driving 4 ohm loads, and one is driving the two 7" SEAS excel driver pairs similar to your speakers.

One 909 is driving the downstairs system which is pretty close to 6 ohm across the board. The other is driving the top section of our Eagan system which is a 4 ohm load.

You can push these amps hard without duress.

I can not think of a better amp to drive your very nice speakers.

Jump on that. I watch these all the time, and that is the best 909 to come up on eBay for a very long time.

Do yourself a favor and put that old B & K out to pasture.

 

[Irvrobinson]

And, Swerd, think about it, how many times are Mark and I in complete agreement?

 

[Irvrobinson]

Input watts (drawn from the AC line) and output watts (measured at the loudspeaker output terminals) are not the same thing. Although there is a relationship, output watts should always be higher than the power drawn from the AC line in watts. The exact amount depends on the power supply and amplifier's overall efficiency, so there is limited value in comparing the two.

Dead wrong. Law of conservation of energy says so. A watt is a watt, one joule per second, actually. Amplifiers have an efficiency factor, and it is absolutely impossible to have an efficiency factor greater than 100%, which is what you're proposing. The most efficient amplifiers available, so-called Class D types, are advertised to be about 90% efficient, while Class A amps are often in the 25-30% efficiency range. Put in 1000W from the wall outlet and get ~250W at the output terminals. Most Class AB amps are usually about 65% efficient.

 

[Swerd]

For a 909 in that condition, the buy it now price is excellent value. If you let the bid go it will probably go up to $1200 or higher. For that amp $1200 would not be excessive.

Quick question. The dimensions of the Quad 909 are said on ebay to be 5.51” x 12.63” x 9.45”. Which is the height?

I downloaded a Quad 909 owner's manual which says:

Width 321 mm = 12.64"
Height 140 mm = 5.51"
Depth 240 mm = 9.45"​

I'm mainly concerned with the height. Does 5.5" sound right to you? That would make the 909 easily fit where I kept my larger and heavier B&K.

Second question is about the IEC AC cord. My set up now requires more than the 2 meter long cable mentioned in the 909 manual. I would guess I can use the longer power cord from my old amp. The illustration in the 909 manual shows a 2 prong connection. My B&K power cord has a grounded 3 prong connection. What do your 909s have?

 

[TLS Guy]

Quick question. The dimensions of the Quad 909 are said on ebay to be 5.51” x 12.63” x 9.45”. Which is the height?

I downloaded a Quad 909 owner's manual which says:

Width 321 mm = 12.64"
Height 140 mm = 5.51"
Depth 240 mm = 9.45"​

I'm mainly concerned with the height. Does 5.5" sound right to you? That would make the 909 easily fit where I kept my larger and heavier B&K.

Second question is about the IEC AC cord. My set up now requires more than the 2 meter long cable mentioned in the 909 manual. I would guess I can use the longer power cord from my old amp. The illustration in the 909 manual shows a 2 prong connection. My B&K power cord has a grounded 3 prong connection. What do your 909s have?

I just measured my 909 and it stands 5.5" high.

It has a 3 pin IEC connector. However the power cord that comes with the Quad amps, does not have a ground wire in the cord! That was so Peter was not pestered by people with ground loops. It is generally asking for trouble to ground a power amp. The best ground point in a system is the preamp. So if you use a power cord with the ground connected you might need a ground break.

 

[Alex2507]

I thought I was in some form of audioholic recovery but all this talk of amps and then what really did it was the pictures. I knew I was on shaky ground when I found myself circling back to check out the fleabay listing. All I know is that the eventual owner of that amp can count his lucky stars I'm in no position to buy it myself ... 'cause I'm like that.

 

[slipperybidness]

Are you sure about that? Because every amp I have ever seen specs on defies that statement. I already gave info on the Niles SI-275. My Outlaw M200 mono-block draws 600 Watts and produce 200W RMS @ 8 and 300W RMS @ 4 ohms.
I could see how with capacitors you might produce a short term wattage in excess of the input (though I don't know that is possible), but RMS watts are sustained.

Yeah......that had to be a mistake!

You can't achieve >100% efficiency.

 

[Dan]

I had an issue with my B&K amp a few years ago. One of the wall mounted rear speakers had the screw cap on the binding post work loose and the speakers wires touched creating smoke and a nifty short. The fuse on the amp did not blow. Instead the whole channel blew. B&K was still in business so I sent it back to them for repair. Shipping was not cheap.

Your issue is different but I point it out in case the fuses are fine, it may be the power supply.

 

[Dan]

I had an issue with my B&K amp a few years ago. One of the wall mounted rear speakers had the screw cap on the binding post work loose and the speakers wires touched creating smoke and a nifty short. The fuse on the amp did not blow. Instead the whole channel blew. B&K was still in business so I sent it back to them for repair. Shipping was not cheap.

Your issue is different but I point it out in case the fuses are fine, it may be the power supply.

I wrote that yesterday at about five when a huge thunderstorm with hail struck. A loud boom, the house shook, the alarm went off even though it was not activated. I think we took a near lightning hit. Apparently it never posted. The wifi is fried, one outlet in the kitchen is out and one garage door opener is dead. Not yet sure if it's the outlet or the opener. Now I've got my own electrical issues to deal with, but I'll still help Rich tomorrow.

 

[slipperybidness]

I wrote that yesterday at about five when a huge thunderstorm with hail struck. A loud boom, the house shook, the alarm went off even though it was not activated. I think we took a near lightning hit. Apparently it never posted. The wifi is fried, one outlet in the kitchen is out and one garage door opener is dead. Not yet sure if it's the outlet or the opener. Now I've got my own electrical issues to deal with, but I'll still help Rich tomorrow.

If that is the extent of the damage from nearby lightning, then consider yourself lucky!

My neighbors took a direct hit several years ago, I saw it hit out my kitchen window. Scared the crap out of me and my pets!

Neighbors lost every single item plugged into an outlet, and had a large hole in the roof shingles.

I lost my PC and maybe 1 or 2 inconsequential electronics. I was already kind of thinking about replacing my aging PC, so I also got very lucky.

@Swerd it seems like you are just planning to replace the fuse and see what happens. I just wanted to mention--When you check fuses, you should always use a continuity tester and not just rely on visual inspection. Visual inspection is less reliable, it could be poor continuity but you can't see that the fuse is blown.

 

[slipperybidness]

@Swerd just another thought here--How are you triggering that B&K amp to switch on/off?

If you are lucky, perhaps it's a problem with your trigger cable or signal?

 

[highfigh]

@Johnny2Bad, @Alex2507, @KEW, @TLS Guy, @Irvrobinson, @Dan and all others still interested.

I pulled out the amp this afternoon.

• This amp is 19 to 24 years old. I bought it used in 2008, for $400 plus shipping. Unfortunately B&K is out of business. I wonder what it might cost for local repair?

Irv – thanks for your comments on the Quad 909 design. A recommendation from both you and TLS Guy is worth something. Any suggestion of a good price to bid?

ATI bought the assets and all documentation for B&K, so manuals are available.

 

[Swerd]

@Swerd it seems like you are just planning to replace the fuse and see what happens. I just wanted to mention--When you check fuses, you should always use a continuity tester and not just rely on visual inspection. Visual inspection is less reliable, it could be poor continuity but you can't see that the fuse is blown.

The fuse is ceramic, white and opaque. I can't see inside if there is a broken filament. Believe it or not, I don't have simple volt-ohm meter to use as a continuity tester.

@Swerd just another thought here--How are you triggering that B&K amp to switch on/off?

If you are lucky, perhaps it's a problem with your trigger cable or signal?

I use the rocker On/Off switch on front of the amp. There is no jack to hook up a remote trigger.

So, it is possible that the rocker switch has failed.