blowed'em up good; blowed'em up REAL good!

[jdm56]

OK, so I was doing a little side-by-side comparison, just for fun; my little RCA Pro-LX5's that normally live in my bedroom, and the B&W 703's from the main rig. Before making a switch with the speaker leads, I turned off the receiver (good), but I didn't think to turn off the power amp that was driving the B&W woofers (bad). Well, as fate and stupidity would have it, I managed to let the ends of the speaker wires touch, and the next thing I knew after the noise and the sparks had settled, I had a non-functioning Sony ES amp and a non-functioning Pioneer Elite receiver on my hands.

So, later that same day I was off to KC to the stereo hospital. Now I'm just waiting to see how bad it's going to be, and whether or not they can even be fixed. Or maybe I should say, whether or not they are worth fixing.

I can't believe that after 30 years or so of being an audio dork that I would pull such a silly stunt. All I can do is pass along my experience and warn everyone to be careful. All it takes is one little strand of wire and about a nano-second, and your precious rig can become toast![:'(][:$]

[Daddy Dee]

Bummer.... big time.

Hope you get good news from the stereo hospital.

You are right. it is easy to happen. I sometimes switch stuff and

then realize it was still hot. Just lucky on that day. I try not to

push it.

[Def Leper]

The first thing most of us electrical guys were taught by the old timers was to check to make sure the equipment was off, and check it twice, and the second lesson was to leave the jewelry at home.

They often punctuated the lesson with hands that were missing a finger or parts of a finger, and spiced it up with descriptions of watching the Darwinian end of former coworkers who didn't check twice, including graphic descriptions of various forms of electrocution, fast cooking with microwaves, and other horrible forms of electrical death.

I think you got off pretty lucky and have a good tale to help remind you in the future.

[Deang]

Did you check the fuses under the lids?

[OldGuy]

So True. I remember when back in1949 I worked for Ma bell ( Before she became a MF) The first day they showed the group of new recruits a safety film where the star fell of a telephone pole and left his ring and associated finger at the the pole step. My wife could not talk me into a wedding ring and after too many years working around electronic equipment I never did wear another ring.

[jdm56]

Did you check the fuses under the lids?

I pulled the bonnet on both units, but the only fuses I could find were on the AC coming in and in both were OK. So I let'em set for quite a few minutes, just to see if perhaps they would reset themselves, but nope -all I could get was flashing red protection lights. Figuring I'd done enough damage for one day, I buttoned them both back up and took them to the shop.

I wonder what the damage will be dollar-wise? I'll probably have to sell one or both to pay for fixing them.[]

[fini]

Big Jim McBob & Billy Sol Hurok

[jdm56]

I want my,

I want my SCTV...

[D-MAN]

More than likely, the final output transistor stage(s) is/are blown, being that they are presumably direct coupled as with most SS amps.

If this is the case, it isn't actually all that bad, and yes, they can be fixed.

DM

[Tom Adams]

Some of you old timers her might remember this story, so at the risk of repeating myself.........

One day while my Dad was working on one of our cars (back when you could actually work on them) my Dad decided that his son, at the ripe old age of 11 years old, needed a lesson in voltage, amperage, and resistance when he saw me shy away from the 12 volt battery that spun over the 455 cubic inch motor in our Olds Ninety-Eight. He explained that the battery would not shock me, even though it could deliver A LOT of current, due to the massive resistance of the human body. After many questions from me and several explanations, Dad went back to work. In the mean time, I would grab the battery terminals in amazement of my new found knowledge. After a few minutes, my Dad hears this loud ka-POW! Turning around he sees his one and only son with one of those Three Stooges wide eyed horror looks. He then notices that his dumass son is holding a screw driver in each hand - one of which is sans a good chunk of metal from the shaft. That's right.....at the age of eleven I discovered how to arc weld! LMAO.........[]

Tom

[jacksonbart]

.

[jdm56]

Some of you old timers her might remember this story, so at the risk of repeating myself.........

One day while my Dad was working on one of our cars (back when you could actually work on them) my Dad decided that his son, at the ripe old age of 11 years old, needed a lesson in voltage, amperage, and resistance when he saw me shy away from the 12 volt battery that spun over the 455 cubic inch motor in our Olds Ninety-Eight. He explained that the battery would not shock me, even though it could deliver A LOT of current, due to the massive resistance of the human body. After many questions from me and several explanations, Dad went back to work. In the mean time, I would grab the battery terminals in amazement of my new found knowledge. After a few minutes, my Dad hears this loud ka-POW! Turning around he sees his one and only son with one of those Three Stooges wide eyed horror looks. He then notices that his dumass son is holding a screw driver in each hand - one of which is sans a good chunk of metal from the shaft. That's right.....at the age of eleven I discovered how to arc weld! LMAO.........[]

Tom

Now, that's funny!

Thanks for sharing.

[jdm56]

Update for those keeping score:

Still no receiver!!! Over three months and still I wait. Good thing I had some other amps around to press into service.

Actually, I got the Sony ES amp and the Pioneer Elite receiver both back over a month ago, but the receiver still had major issues, so it went back to the shop again the next day.[:@] And there it remains.[sn]

[tigerwoodKhorns]

I don't know how hight up or down teh food chain yoru receivers are but have you considered a $225 Panasonic SA XR55K digital amplification receiver? I am using soem Teac digital amps with great results. Really cheap and clean power.

Chris

[Paul]

OK, so I was doing a little side-by-side comparison, just for fun; my little RCA Pro-LX5's that normally live in my bedroom, and the B&W 703's from the main rig. Before making a switch with the speaker leads, I turned off the receiver (good), but I didn't think to turn off the power amp that was driving the B&W woofers (bad). Well, as fate and stupidity would have it, I managed to let the ends of the speaker wires touch, and the next thing I knew after the noise and the sparks had settled, I had a non-functioning Sony ES amp and a non-functioning Pioneer Elite receiver on my hands.

So, later that same day I was off to KC to the stereo hospital. Now I'm just waiting to see how bad it's going to be, and whether or not they can even be fixed. Or maybe I should say, whether or not they are worth fixing.

I can't believe that after 30 years or so of being an audio dork that I would pull such a silly stunt. All I can do is pass along my experience and warn everyone to be careful. All it takes is one little strand of wire and about a nano-second, and your precious rig can become toast![:'(][:$]

Well sorry to hear that,But if you lived down the street from me and you could bring a few beers i would of fixed it for you for free[]

[Jeff Matthews]

I don't know how hight up or down teh food chain yoru receivers are but have you considered a $225 Panasonic SA XR55K digital amplification receiver? I am using soem Teac digital amps with great results. Really cheap and clean power.

Chris

So, Chris, assuming you're not Panasonic's attorney, tell me more about the sound quality of that Panasonic you recommended. Coincidentally, Dean mentioned the SA XR70, which caught my attention since you rarely hear a mention of Panasonic around here.

What I am after is econo-grade, very decent HT with the ability to listen to stereo and still have some good punch. Will this do that?

[tigerwoodKhorns]

Jeff,

"Deaf warmed over" is classic.

I don't think that the Panasonic is going to push the levels that you want to listen to. I am also not sure which Crown model you have but I think that it is one of their very clean models (clean power) and you compared it to the VRD's and said it was a toss up (if I remember correctly) so I don't think the Panasonic is for you.

What the Panasonic does have is a digital amplifier that offers very clean, non-harsh power for horns at a ridiculously low price. The Panasonic SA XR55 is actually an upgrade from the XR70 at a lower price (better binding posts).

A digital amp worked differently than a conventional amp. A conventional amp uses a transistor or a tube which are both switching devlces (thats why tubes are called "valves"). Teh amp keeps the "switch" open at teh point just before it closes, generating lots of wasted power (heat). A pure clas A SS or Tube SET amp are both extremely inefficient and create tons of wasted power (heat) but sound so good and clean doing it that many swear by them.

A conventional amp, while the "switch" is open, creates a waveform. Now, I may be butchering this, but a digital amp, in creating the same waveform as a conventional amp, opens and closes the "gate" extremely rapidly. The resulting sum of the "spikes" from opening and closing rapidly appear to be about the same as the waveform that a conventional amp creates. (a good example of this is integration in calculus where several small "boxes" are summes to approximate a curve). Because digital amps do not keep a "valve" open for long, not much wasted heat is generated. Thus digital amps are very light (because they do not need huge heatsinks to dissipate wasted energy (heat) and cheap to build. The Panasonic receivers and Teac amps feel like empty boxes. They also are very energy efficient. Not a big deal in a home environment (well, maybe in yours at teh volume that you lsiten to!!) but a huge deal in commercial settings and portable gear. The "problem" with digital amps is that in approximating the curve, they generate a lot of distortion. However, and I do not claim to completely understand this part, or any part of this for that matter, the distortion can be maneuvered high up in the frequency rance and cut off with an appropriate filter network (capacitors).

Do a search here (if you can get it to work) on the Teac L700P amp on this forum. Is uses a Tripath chipset that delivers 30 wpc at 6 ohms. These were available recently for $100 new and just delivered unbelieveably clean power. Notice I didn't say "for the price." Several of us here picked them up just to play with. It's just a great little amp.

When I bought my Peach the only amp that I had was my Teac so I ran it and was amazed. I then bought a QSC and stored the Teac. I am now tri-amped and use the QSC for my woofer and two Teac's (one for midrange and one for tweeters). It is a great combo.

Chris

[jdm56]

I don't know how hight up or down teh food chain yoru receivers are but have you considered a $225 Panasonic SA XR55K digital amplification receiver? I am using soem Teac digital amps with great results. Really cheap and clean power.

Chris

I have read a lot of good things about the Panasonic digital receivers, but I have too much invested ("invested" -yeah right.[]) in my Pioneer to trash it. Plus, I really like the firewire connection I use between my Pioneer DV47Ai and the receiver. It lets me use all the bass management, EQ, and other bells and whistles with SACD and DVD-A. Not that I have a lot of those discs, but still it's a nice feature.