For the Dyanco ST-70 amp, Lundahl model LL1682/PP OPT is a prefect replacemernt to the OEM or other manufacturers. At a cost of $150.00 per piece, plus shipping, it is a very affordable upgrade. To complete the install, use the Lundahl 1638 transformer housing for the LL1682PP. Please note, this is NOT a direct drop in replacement, the chassis holes required to mount the 1638 housing are very different and this must be taken into account!

 

A new option is also model LL3723, which is internally pre wired for 4 and 8 OHMS speaker outputs. However, this is a physically larger transformer than the LL1682/PP, so this MUST be taken into account, and it may just be too big for the ST-70 chassis!

It also costs more at US$289.00 per piece and the housing is model 1620.