two issues to deal with if you are saying that you want to stand your amps on their ends assumiong that they do not have cooling fans: `1, standing them on their ends could diminish the flow of cool air, i.e. the hot air flow off the lower tubes would be used to "cool" the upper tubes. 2, is the framework of the amp sufficiently strong to support the weight of the downward shearing pull of the transformers? i'd give arc a call before i tried this.
Amplifier Orientation?
I've got a pair of ARC VT100 MkIIIs and some space issues. One thing I thought about was welding up a rack to hold them vertically, and stashing them behind my front end equipment, which is sitting on a couple Solidsteel racks. Its not like there is any reason to actually see them... I can't intuitively believe there would be an issue with operating an amp in a different orientation--it might even improve airflow around the amp. Just thought I'd see if anyone had any wisdom on this grand plan before I embark on this scheme...