Small problem with K2 S9800 Need information

[jan_slagman]

Hi Loffen,

The same happened to my Cambridge Audio TL 200's (big English transmissione line loudspeakers ) wayback in the early Seventies.
At that time i had a Dynaco PAT 5 preamplifier and a Dynaco ST 410 power amplifier. Unfortunately i forgot to switch on the Dynagard, which was the amplifier's power limiter.
I can recall i played the Abba song Arrival and i believe they were using bagpipes in that song. At a certain moment there was a continuous tone and i played that with a high amplitude. My neighbour who sat next to me all at once knocked me on my shoulder pointing direction left loudspeaker. My goodness, it looked like someone was sending smoke signals through the transmissionline's duct. After that event there was an unbalance between the loudspeakers due to burnt crossover components in the left loudspeaker.

Kind regards,

jan Slagman
The Netherlands

[Zilch]

Good point -- does it still play, or not?

Are we just crying over spilled magic smoke here?

[gtimbers]

Oops! Too much power. Those Metal Oxide resistors sound very nice but are not as robust as the wire wounds we typically use, I am not in the office today so I am not sure exactly where in the circuit those parts are. I would expect your dealer/distributor to take care of the problem, but if you are handy, I can send you some replacement resistors. It will be a lot less trouble for everyone that way. I will send some wire wounds so the problem doesn't happen again.

The Metal Oxide film resistors will barely handle their rating and then pop quickly. The wire wounds will take about double their rating for short periods. They just get hot and start burning the board and surrounding parts but they usually hang in there.

The K2 was not designed to play extremely loud for any period of time. I always have a decision to make regarding the best possible sound, cost parameters, and robustness. We have had no reported power handling failures with the K2 so I am comfortable with my choices on this unit. I'm sorry you had a problem with yours. We can beef it up a bit and you should be O.K. after that. You can send any address information to Giskard and he can get the information to me. I don't view the forum regularly,

Regards,

Greg

[subwoof]

Back when I made some "poof-proof" networks for the installs that had an impossible access, I used the 25 watt adjustable resistors ( see picture ) that we actually mounted to a panel with large bolts.

The drivers were 2482's so we wern't concerned about the occasional clip BUT fire was a real threat so into the metal boxes they went...

Now I use them and the 50-70 watt flat types that were used in very large wiper motor speed controls by some detroit company. Found them in 4,5,7,8,20 ohm in stacks of 10 for a buck each....:o)

sub

[Valentin]

thats that

nice ofer take it

or wait a long time for replacements.

[Loffen]

Thanks Guys.

I will of course take Mr Timbers kind offer, there is no problem for me to replace the resistors.
Giskard can you please send me a PM so I can give you my address ? I do not know your username on the forum.

I did also receive an answer from Mr J.Curl it was short but he did say the same as Mr Timbers.
(I rearly use "Mr" in front of anybodys name,but here I am talking to two of the persons that have all of my respect and admiration )

I will add a picture or two of the crossovers when the work is done.

[Loffen]

Good point -- does it still play, or not?

Are we just crying over spilled magic smoke here?

If you where thinking of the K2s they where not played on after this happend,however the resistors is placed in a paralell configuration,in one crossover they was almost up to specs, in the second crossover one of the resistors where clarly burnt up the other was out of specs.

[Loffen]

Just a short note, I have got hold of Mr Giskard and my address is forwarded.

Thanks guys !

[oznob]

Just a short not, I have got hold of Mr Giskard and my address is forwarded.

Thanks guys !

Hey Loffen, if he hasn't got back to you, Giskard's forum name is 4313B. It is a very kind offer form Harman/JBL's Chief Engineer!

[Loffen]

Just a short update.
I got the resistors from Mr Timbers yesterday and I will replace them later this week.
I will add a picture or two when it is all done.