Overheat + amp turns off

ph0nghw0ng · #1 06-10-2010, 08:28 PM

Hi!

I have a Yorkville BM200 (classic 1x15 combo amp) hooked up with a David Eden d210T (2x10 cab 250W 4ohm).

I play a Fender Jaguar Baritone guitar through it. The other day i was playing kinda loud, enough to get some distortion with volume at 5-6 (no pedals, effects or whatsoever) and the amp turned off. The amp felt hot to the touch, and power came back 5 minutes later.

In my opinion there's no doubt that the amp switched off to protect itself, but what could be the cause of the overheat?

I use speaker cables to connect the cab to the combo.

Thanks!

chokeslam512 · #2 06-10-2010, 08:30 PM

My guess is that you are running it below the minimum impedance with the 4 ohm extension cab.

Rick Auricchio · #3 06-10-2010, 08:34 PM

No, the specs say it can run a four-ohm extension cab and is OK with two ohms.

Could have been to hot in the room. Not enough airflow through the combo's head. Low line voltage.

5port · #4 06-10-2010, 08:43 PM

Quote:

Originally Posted by ph0nghw0ng

Hi!

I have a Yorkville BM200 (classic 1x15 combo amp) hooked up with a David Eden d210T (2x10 cab 250W 4ohm).

I play a Fender Jaguar Baritone guitar through it. The other day i was playing kinda loud, enough to get some distortion with volume at 5-6 (no pedals, effects or whatsoever) and the amp turned off. The amp felt hot to the touch, and power came back 5 minutes later.

In my opinion there's no doubt that the amp switched off to protect itself, but what could be the cause of the overheat?

I use speaker cables to connect the cab to the combo.

Thanks!

Not every cab is dead on impedance wise. In other words your extension cab may really be 3.7 ohms and your on board speakers may be 3.8 ohms which would put the impedance slightly under 2 ohms. This would pull extra current from the amp causing it to run hot and trip.

megadan · #5 06-10-2010, 08:48 PM

Quote:

Originally Posted by 5port

Not every cab is dead on impedance wise. In other words your extension cab may really be 3.7 ohms and your on board speakers may be 3.8 ohms which would put the impedance slightly under 2 ohms. This would pull extra current from the amp causing it to run hot and trip.

This seems, if unusual, like a pretty solid premise. Some amps run a true 2 ohm load better than others.

ph0nghw0ng · #6 06-11-2010, 05:07 PM

Quote:

Originally Posted by 5port

Not every cab is dead on impedance wise. In other words your extension cab may really be 3.7 ohms and your on board speakers may be 3.8 ohms which would put the impedance slightly under 2 ohms. This would pull extra current from the amp causing it to run hot and trip.

Ok so what can I do about it? It wasn't really hot in the room. Do i play too loud for my amp? I mean, is it ok for me to crank the volume until the loudest chords (i play guitar through it) distort? The guy at the shop where i bought the cab is a good friend of mine and said impedance would not be an issue, since the amp external speaker output is geared for 4 ohm imped. Said amps are tolerant to lower impedance than their minimum rating. It has its logic, since they would not tell you to plug minimum 4 ohms otherwise, no? Could the cab be faulty? Anyone ran into this problem himself?

Quote:

Could have been to hot in the room. Not enough airflow through the combo's head. Low line voltage.

I'll work on airflow. Low line voltage: can you explain?

Thanks!

will33 · #7 06-11-2010, 05:52 PM

Sounds to me that cranking an SS bass amp into full on distortion combined with using the lowest possible impedance just plain drew too much power/got too hot. Get a dirt pedal for the guitar, or better yet, a real guitar amp.

will33 · #8 06-11-2010, 05:54 PM

Low line voltage means the power at the wall socket it's plugged into is too low. That would be an electrical problem with the building, not the amp but amps will have problems if the power source isn't what it's supposed to be.

coreyfyfe · #9 06-11-2010, 06:08 PM

Quote:

Originally Posted by ph0nghw0ng

The guy at the shop where i bought the cab is a good friend of mine and said impedance would not be an issue, since the amp external speaker output is geared for 4 ohm imped. Said amps are tolerant to lower impedance than their minimum rating. It has its logic, since they would not tell you to plug minimum 4 ohms otherwise, no? !

True for tube amps, they tolerate lower-than rated impedance better than higher, but as far as I've read it's the opposite for solid state amps. They say minimum 4 ohm because 4 ohms (+/- a reasonable % variance) is the minimum the amp can tolerate.