Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: davantalus on September 22, 2012, 09:20:27 PM

Title: Possible heat issue?
Post by: davantalus on September 22, 2012, 09:20:27 PM

Crack assembled! Voltages check out and the sounds are heavenly. Powder coated pictures to follow eventually. :)

I've notice that my chassis gets uncomfortably hot to the touch. I was expecting the tubes to run hot, and the chassis to run a bit warm... but I wasn't expecting to be unable to pickup the chassis after powering it down.

Is this typical? Anyone have thoughts?

What's the melting point of the insulator material?

Title: Re: Possible heat issue?
Post by: Laudanum on September 23, 2012, 12:01:06 AM

Try a related search of this forum.   This seems to be a common question and I think there have been replies from the Bottlehead guys themselves.

Title: Re: Possible heat issue?
Post by: Doc B. on September 23, 2012, 07:10:28 AM

Yeah, it gets very warm because the cathode resistors under the chassis get hot. That's why there are cooling vents. If your voltages are correct you have nothing to worry about.

Title: Re: Possible heat issue?
Post by: davantalus on September 27, 2012, 08:38:54 AM

Strange!  Maybe I'm crazy is it possible that my Crack has "cooled down" a bit since first run?

The chassis plate seems to have gone from "blazing" to "pretty warm" at similar listening levels.

Title: Re: Possible heat issue?
Post by: Doc B. on September 27, 2012, 08:51:31 AM

You could remeasure the voltages and see if anything has changed. If the voltage across a cathode resistor has lowered the power dissipation has lowered and it will be radiating less heat. P=V²/R

Title: Re: Possible heat issue?
Post by: Mak33 on October 16, 2012, 06:46:36 PM

Quote from: davantalus on September 22, 2012, 09:20:27 PM

Crack assembled! Voltages check out and the sounds are heavenly. Powder coated pictures to follow eventually. :)

I've notice that my chassis gets uncomfortably hot to the touch. I was expecting the tubes to run hot, and the chassis to run a bit warm... but I wasn't expecting to be unable to pickup the chassis after powering it down.

Is this typical? Anyone have thoughts?

What's the melting point of the insulator material?

I'm with you davantalus... Maybe it's just my low pain tolerance, but I could not describe my chassis as "warm" when it's on for over an hour.  If some believe that "warm" is just below a burning sensation to your skin, then maybe my definition of "warm" is a bit off, but I'd call it hot.  I haven't taken a thermometer to it, but it might be interesting to see the value.

Another point... I'm using an aluminum knob on the POT with no plastic or insulating core and it also gets warm.  Not nearly as hot as the chassis, but definitely warm to the touch.

Title: Re: Possible heat issue?
Post by: Grainger49 on October 17, 2012, 02:00:57 AM

I started a FAQ Thread (http://bottlehead.com/smf/index.php/topic,2408.0.html).  Heat is question #4.