Hi Charles, no just a cost issue as I am replacing many resistors and the total cost starts to add up. I hope to really learn a great deal with this project and in the end have a $1500 amp that sounds like $10,000. Ha!
My next amp project will be to build a killer tube amp with Duelund parts, but I have much to learn. For this project, building a new power supply and changing out virtually every cap and resistor with sold quality Mills and Mundorf parts is enough. The amp's circuit and iron are OK, but not worthy of Duelund.
I am quite intrigued with what the end result will be. One can purchase a China made amp like my TAD 60 for under $400 new in China. Add another $650 in parts and I think I could have a very nice 50 watt stereo amp. The Bez amp company in China sells amps very, very low in price. One can buy 50 OtL monoblock amps for $1300. The build quality is good, but the parts are cheap. Great amps to learn on and modify.
My TAD 60 was made by the Bez Co., but it has many upgrades over their stock $400 amp. I will have to build a nice chassis extension out of wood to fit the much bigger film and big can caps. Fun stuff!