Just finished my 5E3 and it sounds great. I took one of several good pieces of advice from the @robrob website and added a Master volume to it. Used one of the input slots as was one of his recommendations. While the speaker still needs a break-in period, I love the amp! Now I'm taking on my last task for a while, which is to construct a 5F6-A and I'm starting to gather up all the stuff I'll need. But owing to my experience with the 5E3 and the master volume, I definitely want to do the same with this amp. So here are my questions for the gang. 1. @robrob shows a couple of master volume setups that would only be easy if you were starting from scratch: the Type 2/Lar-Mar and the Frondelli. Does anyone have any experience with these and any comments before I get started? I think I'm trending toward the Type 2 but would welcome any comments. 2. Placement will not be as easy. On the one hand, there's plenty of room on the bottom of the chassis but the problem with that is that it will only be accessible with a screwdriver to take off the back panel. It looks like I've got enough space to put it right in between the 4 input jacks. But I wonder about whether or not the position will have an impact on the input signal being in such close proximity. The other spot would be the hole for the "Ground" which is at the far end of the chassis, right in front of the transformer. The hole is a little big, but doable--and, I've got nothing else to put there. Question is, am I too close to the transformer even when using coax for leads? Am I asking for trouble here? Any comments are welcome, as usual.