How should I punch 3" by 3" holes in the original ST-70 cage for additional ventilation?

So reading about heat being contained in a small area I have some concern although I am not sure my concern comes from reading these posts rather than the issue itself. I have an external 2tube dac with 2" of clearance from the top of the dac to the shelf above it. All my shelves are open, meaning there are no front, Back, on sides. Heat to the touch does not exists,however it is warm which is natural an is how I would describe it...warm not HOT.
With my description do you think a fan is necessary?
After reading this I am not sure.

bluemeanies wrote:So reading about heat being contained in a small area I have some concern although I am not sure my concern comes from reading these posts rather than the issue itself. I have an external 2tube dac with 2" of clearance from the top of the dac to the shelf above it. All my shelves are open, meaning there are no front, Back, on sides. Heat to the touch does not exists,however it is warm which is natural an is how I would describe it...warm not HOT.
With my description do you think a fan is necessary?
After reading this I am not sure.

I don't think so.  Consider old tube TV's.  They used to be ALL tube and they were not well ventilated cabinets.

New2Tubez - I forgot completely about the recent thread on the AB board and its properties which mitigate need for TDR. But others - be aware that use of the Weber WS-1 SS rectifier module necessitates some sort of delay, and careful monitoring of AC line voltage.
bluemeanies - Like the SP-14 pre, your tube DAC is in no danger of overheating. It is only a possible concern for high-power devices such as ST-120s, M-125s, etc.

dmagazz wrote:ahhhh/ nice. very well thought out.
these supposedly work very good
https://www.quietpcusa.com/Noctua-Anti-Vibration-Fan-Mounts-NA-SAV2-P1028.aspx

Thanks

I got those very ones. In black too!
Problem is the cage hole perfs are too small. When I tried to pull the fastener through the perf, it snapped. I tried more than one. I really don’t want to make the perfs bigger.

I think installing the fan on the back of the cover and having it push air past the transformers is the better configuration from both a performance and appearance perspective.

Thanks Kentley and corndog71
Appreciate your input.

Dogstar, you are correct re: placement of fans at the rear. I feel much more heat being displaced now that I've taken your advice. An added benefit is even less noise pollution from rotating blades than ever before. Onward and Upward!