Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: audiophileboss on August 14, 2013, 10:01:25 AM

Title: Resistors get hot
Post by: audiophileboss on August 14, 2013, 10:01:25 AM

The ceramic resistors are getting hot. Music plays through both channels....any help?

Title: Re: Resistors get hot
Post by: Doc B. on August 14, 2013, 10:05:48 AM

Sounds like you don't really need any help. The cathode resistors are doing what they are supposed to do.

Title: Re: Resistors get hot
Post by: Grainger49 on August 14, 2013, 11:07:32 AM

IIRC, those are 5W resistors.  That means they are supposed to put out some watts, but not 5, Paul is more conservative than that. 

BTW, the tubes, top plate and transformer will also get hot.  It is the nature of tubes and Bottlehead equipment.  Look in my Corner at the FAQ Thread (http://bottlehead.com/smf/index.php/topic,2408.0.html).

Title: Re: Resistors get hot
Post by: audiophileboss on August 14, 2013, 11:35:00 AM

Is my amp ok to use?

Title: Re: Resistors get hot
Post by: audiophileboss on August 14, 2013, 11:41:18 AM

I left it on for 2hrs. The heat was consistant. No caps or wires got hot. But the resistors could COULD be hot enough to burn my finger...the values are correct when I ohm it out, the plate, 6080 and transformer get warm(6080 gets hot). Is it ok to use?

Title: Re: Resistors get hot
Post by: audiophileboss on August 14, 2013, 11:41:48 AM

One more thing, I am useing a 1 amp fuse that Eilenne sent me.

Title: Re: Resistors get hot
Post by: Doc B. on August 14, 2013, 11:52:31 AM

Yes it is doing exactly what it is supposed to do and it is OK to use. As your subject header says, resistors get hot. That is what they are supposed to do.

Title: Re: Resistors get hot
Post by: audiophileboss on August 14, 2013, 11:56:57 AM

Thanks Doc! Bottlehead rocks!

Title: Re: Resistors get hot
Post by: Paul Birkeland on August 14, 2013, 05:33:25 PM

Hey there Boss,

If the voltages at 7/9 are correct, then the heat across the 3K resistors is correct.

They are 10W resistors, dissipating 2.7W, but they still warm up nicely.

-PB

Title: Re: Resistors get hot
Post by: Grainger49 on August 15, 2013, 12:18:41 AM

Here is how to figure it out.  The resistors are well sized.  If the voltage across them, from the cathode to ground, is within what is specified everything is as designed.