Pass Labs Amps - Does the heat bother you?

A few rules of thumb, based on experience.

• Class A, Tubes, cathode bias, heat dissipation = rated power * 6
• Class A-B, Tubes, fixed bias, rated power * 2
• Class A, SS, rated power (@ 8 ohms) * 4

The quoted figure for the 350.8 (Class AB) is 600-800 watts.

If you want 250 watts, based on Google's AI summary, class D would be somewhere between 25 and 50 watts (10 to 20% of rated output).  

I ran a VAC 70/70 for many years (400 watt dissipation I think)  and it made my room warm!  Kept it OK in Winter, Hot in Summer.

@dman777 

I own a XA25 and a X150.5. They power different speakers and I use them every day. I keep both powered and just switch the input signal around. I live in the SoCal area and it's not as hot as in the Desert, but it still gets hot. The previous amps that these Pass replaced where Benchmark AHB2 configured in Mono. those runs warm to the touch.

So, with that said, I can tell you that after a couple of hours, I can feel the heat coming from those amps. BUT in the end, they are worth every penny i spent and i would gladly deal with the inconvenience of the heat dissipated. Its musicality and performance are far greater than the heat inconvenience or cost of ownership.

The heat generated is not bothersome at all. A small desktop fan combined with house air; you won't notice it at all.

This is my opinion living with these Amps and YMMV

Good luck 

My XA-25 gets hot exactly as Pass said it would...put your hand on the heat sinks and you can leave it there for a few seconds, according to them. Also I leave space above the amp so as not to to cramp its style. I imagine if you have a very small room you may be concerned about heat but in a normal room...meh...the Pass isn't as hot as my little Dennis Had Firebottle SEP tube thing that I switch to when the mood strikes me, but also it gets plenty of room so again...meh...if you worry about heat there are plenty of boring Class D amps out there.

I have the 600.5 and it does get hot on the other hand my boulder 2060 is class a and only gets warm. So they designed it that way. My krell monoblocks  get hot and I put low noise fans on them.my d sonic 1500 watts in8 and 2400 in 4 don't get hot. My smsl gan  pa x 500 watts  mono no heat. Class d is becoming more desireable.enjoy the hunt.

Wear fewer clothes. No, seriously. Our living room faces WbyNW and gets warm in summer. Add in the energy from a well driven tube amp and it can be downright sultry. I usually wear gym shorts and a t-shirt.

Relax. Get comfy. Enjoy. 😊 

Happy listening.