Just wondering as my 5e3 was from a Zenith Chassis with a Zenith PT and a stancor OT. though I figured the transformers should work as the tubes were the same except for the octal preamp tube which was changed to a 12ay7/12ax7 tube type. I built the amp and it sounds great! For my new 5f4 build the trannies are as follows and I was told on an other board by PM it will not be a true 5f4 due to the different trannies. The turret board will be a 5f4 and the tubes will be the same as will the controls ect so how much differnce will these trannies make? So I wonder how much the transformers have to do with making things different. For my 5f4 build I am working on now I have the chassis and PT out of a Hammond Tone Cabinet and the PT is a Hammond Tranny AO 20927-10 which is a 360 0 360 V and the Output tranny came out of a Peavey Duel amp that had 4 6l6s. I was told I could not use the OT (s) that was origionally on the chassis, as it was from a 2 channel (treble and bass one pair each 6v6 running each channel with a separate bass and treble OT ) amp and I am running two 6l6s. Peavey and some one else told me I could use this Peavey OT only since it was for a 120 watt amp and I was using only two 6l6;s instead of 4 the OT would read differently and you shift the taps so I will not use the 4 ohm tap as the amp now would see it as 2 ohms and the taps I am using the 8 ohm tap will now be for 4 ohms and the 16 ohm tap will be for the 8 ohm tap. So I wonder now much of a difference using them trannies will make than buying trannies for a 554 build? I think they should work fine. Opinions?