You need a thermostat. Here is a thread I posted (graphic) of someone who "thought" a UTH without a thermostat would be just fine. Your method of "using more aspen" won't work, especially if he burrows. Don't risk it. Don't be cheap.
thanks for the feedback, well, where can i get one other than amazon, or ebay.
Reptiles
0.0.1 - Rhacodactylus Ciliatus, Cheerio
Mammals
1.1 - Canis Lupus Familiaris, Little Man & Molly