Rotel 1056 Died!

[Scherr]

My six month old Rotel 1056 started shutting itself off last night while watching TV. It was very hot to the touch.

This morning, I tried to turn it on and it was dead! I saw smoke coming from the top of it.

It goes back to the dealer tomorrow for warranty service.

Scott

[Aussie Geoff]

Scott,

Bummer!!

I hope the repair / return is quick

Did you have good ventilation for the unit (2 inchse at top, not a closed cabinet etc)? If not they can heat up too much... Mostl likey though a faulty unit, especially with the bleed through you were getting on the Zone 2

Geoff

[Scherr]

Thanks, Geoff. It was ventilated adequately. I am going to take it back to my local dealer who has always treated me well for many years and will report back.

Scott

[Scherr]

Just wanted to post an update. Took my Rotel to the dealer who will fix it under the warranty. They suggested I buy a multimeter and test my speakers and wires for defects.

I did just that. I have 2 Paradigm Studio 40's, v.2, 4 Paradigm Studio 20's, v.2, and a Paradigm CC, v.2.

The resistance for the 4 20's and one of the 40's was 4.0 on each. This is normal according to the dealer because these speakers are rated at 8 ohms, for in reality 6 ohm speakers. (Resistance is always less than ohms -- usually somewhere around 75% give or take).

The CC read 6.4 which the dealer said is normal because it is a true 8 ohm speaker.

Interestingly and unfortunately, the other 40 read 7.6 which is much higher than it should have been. This speaker is defective I will have it fixed although it is not covered by warranty since I bought it used.

I am relieved to discover the problem. A suggestion: if your received shuts down in protection mode or dies on you, test all speakers and wire with a multimeter.

Scott

[Andrew Pratt]

Good catch Scott but its too bad about the speaker being the problem. You might try contacting Paradigm directly and see if they can help...you never know they might offer you something towards the cost of the repair.

[Scherr]

Thanks for the tip, Andrew. I contacted Paradigm and they were extremely helpful. They said that they would call me back after checking with Research & Development to determined the mostly likely cause and they can sell me the part directly. A tweeter or midrange or woofer is only $100.00 and a crossover is only $80.00. Not bad considering the cost of Studio 40's.

Scott

[Andrew Pratt]

Nice to see they're able to help.

[rhoffman000]

Just curious, if there was a short, shouldn't the resistance be less, not more? Also, if resistance was higher than normal, shouldn't that tax the amp less?

[soundhound]

You are correct rhoffman000

[GosonFletchy]

I think the problem is that you let the smoke out of your 1056. Once you let the smoke out of electronics they just don't seem to work quite the same . Hopefully you will get the 1056 fixed promptly and be back up and running.

G.

:grab:

[Scherr]

You guys are correct. Paradigm called back and said that the Studio 40 with the 4.0 reading is the defective speaker. Since the 20's are a 2 way speaker, their resistance levels are lower than the 40's which have a midrange and a woofer. Since resistance does not include the tweeter, which is separated by the crossover (and I tested this by removing the binding posts), either the midrange or woofer of the 4.0 speaker is fried. Hence, the reading of roughly half of the other speaker.

Time to pull out the woofer and midrange and test resistance to see which one is fried. You guys were right as always.

Thanks!

Scott

[Scherr]

Another update:

Paradigm called back. They spoke to Research & Development and they are now certain that the 7.5 ohm resistance speaker is the defective one!

This is what my dealer told me, but Paradigm called yesterday suspecting the 4.0 speaker, but then today spoke to R & D who said it is definitely the 7.5 speaker and is certainly either a damaged woofer or midrange. Very interesting.

Scott

[Fred7]

If one of the drivers in the speaker is an open circuit (completely dead) the resistance (impedence) will most likely rise because they are wired in parallel so that would be the bad one.

[Scherr]

Thanks, Fred! That makes sense.

Scott

[shadow]

Sounds pretty bad when Paradigm cannot decide which speaker is bad. Not very good protection circuits on the Rotel either.

[Scherr]

I asked Paradigm about why they were suspecting the other speaker at first. He said that he initially suspected the lower resistance speaker because the center channel, which has two drivers in addition to the tweeter, had a higher resistance and he thought the number of drivers would cause the 40's to be rated for a higher impedance.

He then relayed how I had tested the speakers to Research & Development who concluded that the 40's and 20's all have the same impedance and that the center channel had a higher impedance because center channels take on much of the power needs in movies and they purposely make it easier to drive. R&D is certain that the 7.5 speaker is defective and I suspect that they did a resistance test in the lab.

My friend has 60's, exactly the same as the 40's except the enclosure, and I will test his with a multimeter.

There are threads over at hometheaterforum and avsforum about the protection circuit of the 1056. They apparently do not have as solid a protection circuit as mass market receivers like Denon, Yamaha, etc. This individual bought a 1056, it died immediately, had it replaced, and the new one died immediately. He then tested his speakers and determined that he had a problem with one of his speakers.

Scott

[Scherr]

The problem is solved and fixed!

My friend and I opened up the 40's, pulled out the woofers and midranges and tested the resistance. They were all fine.

We then opened up the crossovers and what do you know, in the bad speaker (7.5) the wire from the crossover which leads down to the woofer had come loose (uncrimped). We crimped it back on and restested resistance for the speaker and it was now 4.0 on both. Hooked them up to my friend's system and they sounded great!

So, it was a loose wire in the crossover and not a dead woofer or midrange. All is well.

Thanks for your help.

Scott