Nashville 400 overheating

Bob Tuttle · Post by **Bob Tuttle** » 25 Apr 2001 9:10 pm

I played a gig tonight, and when I was tearing down I noticed the heat sink on the back of one of my Nashville 400's was very hot. The other one was barely warm. I'm running from a ProFex II into the power amp input on the back of the amps. What could cause this amp to overheat? I didn't notice any distortion while playing. Then again, the guitar player was pretty loud, so if it was distorting a bit I might not have heard it.
Thanks
Bob

Mike Brown · Post by **Mike Brown** » 26 Apr 2001 7:51 am

I recommend that you turn the amp on with no input or output connected to it and see if it still gets hot. If it does, the amp might need a bias adjustment or the speaker wiring/harness may have a short, therefore heating just before shutting down. If it does not get hot, it is probably something connected to the amp that is causing it to heat up.

If I can be of further assistance, please feel free to contact me here at the factory. I can be reached toll free at 1-877-732-8391.

Bob Tuttle · Post by **Bob Tuttle** » 26 Apr 2001 8:31 am

Thanks Mike. I found one of the speaker wires loose where it connects to the speaker. It probably wasn't getting a good connection. I don't know if that would cause it to overheat or not, but I'll try it on the job tonight and see if it does better.
Thanks again.
Bob

ajm · Post by **ajm** » 26 Apr 2001 11:36 am

Question for Mike Brown (not accusing, just trying to learn): A Nashville 400 is a solid state amp. My understanding is that only tube amps need bias adjustments. If there is something else wrong with Bob's amp, like a resistor out of spec or something else, then it may need a "bias" adjustment, but only because that component needs to be replaced. Is this what you are implying?

Also, since we have people of all knowledge levels reading the forum, a warning flag needs to be raised here. My understanding is that solid state amps can be operated with no load (no speaker) without damage. However, it is NEVER OK to operate a tube amp with no load. True?

Mike Brown · Post by **Mike Brown** » 26 Apr 2001 1:50 pm

Yes, a solid state amp has to be biased also, but our solid state amps have a fixed bias. There could've been other causes in this case, but I'm glad that it was as simple as it turned out.

Our solid state amps are capable of safe operation without connecting a speaker load. We have built them this way since the late to mid '70's. We incorporated a flyback diode circuit in most all tube and solid state amps that allowed them to be operated without a speaker load connected.

Bill Rowlett · Post by **Bill Rowlett** » 27 Apr 2001 7:35 am

Mike/Bob,

I also have an early model (chrome) Nashville 400 that does the same thing. By the end of a gig the heat sink is too hot to touch. This occurs even without an input connected if I set the amp up at home. Both myself and a Peavey dealer have been all through the amp checking voltages and values against a scematic. We have found nothing out of spec. The speaker wiring has been attached/disconnected several times. I wondered if the transformer might have a trickle short? I have considered sending it to Peavey, but never got around to it.

Bill

Mike Brown · Post by **Mike Brown** » 27 Apr 2001 8:25 am

Hello Bill,
Please send the chassis only to me here at Peavey and we will check it out for you. The amp shouldn't get to hot to touch or anywhere near that hot. Our service address is;
Peavey Service Center
Hwy. 80 East
Meridian, Mississippi 39301

Also, please include a note of symtoms and a daytime phone of where you can be reached and we'll be glad to repair it for you.

If you have further questions, please feel free to call me toll free at 1-877-732-8391 until 5PM CST weekdays.

Mike Brown
Peavey Electronics Corporation

Don Townsend · Post by **Don Townsend** » 27 Apr 2001 11:55 am

quote "Then again, the guitar player was pretty loud, so if it was distorting a bit I might not have heard it." That's not a good sign, Bob!!

Bill Rowlett · Post by **Bill Rowlett** » 30 Apr 2001 6:37 am

Thanks Mike,