The LXII fans are like having a leaf blower constantly running. I'd be pretty surprised if it needed any kind of special consideration for heat as long as the front and back are both open.
Fryette LXII:
VHT 2/90/2 from 2003:
Fryette PS-100:
Pics snagged from various sources found via Google. I'm basing the following just on pics so correct me if I'm wrong.
2/90/2 needs to be 2U due to the big transformers and the staggered big bottle tubes, but there's plenty of space left so some vents and a single fan is good enough. Looks like it has a 80 or 120 mm fan, and a pretty thick one at that so it can run at lower speed for less noise.
Looks like the LXII actually has two fans on the sides of the power tubes. Impossible to say from pics but it looks like both are just pulling whatever air is circulating inside the chassis and blowing it towards the power tubes.
The LXII looks like it can be 1U because of the toroidal power transformer, and the less tall but wider output transformers. A more modern design but with the caveat that it's packed to the brim. So cooling is more of a concern, and you can't fit those bigger, less noisy fans either. Without a complete redesign you probably can't do any better for cooling. I don't know if anyone has experimented with replacing the fans with e.g Noctua or reducing their speed with a resistor to make it less noisy.
PS-100 is mostly concerned about cooling some of the load components under the fan, with some minor airflow to the tubes.
I'm guessing that for all of these the fans are more of a safeguard, so that the amp will keep going doing a full set on stage, stuffed in a rack with minimal space for air, in summer heat etc.
Quote from TOP from Fryette support guy regarding the LXII fans:
Some people don’t like fans. Some don’t like heat. We strive for balance.
Fan noise is almost never a “quality” issue. It’s a speed issue. In order to maintain a safe operating temperature, you need sufficient airflow. “Safe” doesn’t necessarily mean safe for the internal parts. It usually means consumer safety. The tighter the environment, the smaller the fan, and the higher the speed needed to maintain the rated temp.
We spent a lot of time on the LXII fan with 3 different fan suppliers and their engineering depts to obtain the best speed:noise. We ended up using a part with much higher speed than necessary and used voltage control to keep it at 80% of max to help minimize noise.
Arbitrarily changing it with “something better” will most likely result in more noise, more heat, or both.
The design of the fan has a big influence on its noise profile so I don't agree "quality" does not matter. This is why e.g Noctua is regarded as the best for computer fans. But it will always depend on usecase, where and how it's mounted too. Fryette also needs to concern themselves with the supply and cost of those fans.
