I think alot of people have bad experiences of Wee Lee Aljunied cos of Sam. But personally, he is actually a very nice and pleasant person. A lot of times when he gives "attitude" is cos of players who don't know how to control their volumes and take care of the equipment. Basic stuff like turning off the volume before turning on/off the amp, adjusting EQ, avoiding feedback, a lot of players don't know as they usually just practice at home with a small amp. When it comes to a bigger amp, there's a need to be more careful. The equipment there has been used for years and years and yet there is usually no buzzing sounds or weird noises or bad feedback from the mics. Every thing there is properly set up, well grounded and maintained.
If you show yourself to know how to take care of the equipment and generally nice and polite, Sam will definitely be nice to you too. Give and take. Remember he earns a living through his equipment. Also, he has a wealth of experience concerning tone and shaping your live sound and shares it freely, all you have to do is ask.