I've gotten a bug to build another tweed amp at some point this year, and I'm trying to take it slow (we'll see how that works out). I was initially attracted to the idea of a 5f4 tweed Super in 2x10, but I've recently begun to think about a 5e7 tweed Bandmaster with its 3x10 configuration. For reference, I've attached .pdfs of both schematics below in the second post of this thread. Some questions have come up that I'd like to have your input on. Since they require a lot of explanation, I've bolded the actual questions and also put them in red. First: In comparing the schematics, the 5f4 Super and the 5e7 Bandmaster are identical in every way, save one part: there is a 4.7M resistor ahead of the V2b grid (pin 2) that connects to the .1 uF coupling cap in the 5f4 Super. In the 5e7, that same resistor is 10M. And that's it. Every other part (including the voltages on the schematic) is the same. So: I've read some about the impressions of these two amps, and they seem to be fairly different narratives (I've never had the opportunity to hear either in person). It seems that the Super doesn't behave exactly like the Bandmaster and that the Super likes to stay clean longer as well. Perhaps this is wrong, but it does seem clear that a tweed Bandmaster is an über cool amp, whereas the tweed Super doesn't seem to have the same volume in its fan-club (aside from Leo himself, I suppose). I don't really understand why this would be the case. The discussion below and some preliminary questions set up the final question at the end of the post. So here are the questions: 1. What difference does the 10M as opposed to the 4.7M resistor make in that spot on each amp? 2. I believe the same PT, OT, and choke can be and (in some cases, at least) indeed was used in both the 5f4 and 5e7. PT: The Super lists the PT as 8087, the OT as 45216, and the choke as 14684. Given that everything is identical on the schematics, including the voltages, it seems evident that both used the Triad 8087, which seems to have a modern clone in the Classictone 40-18073 (http://www.classictone.net/40-18073.html), among others. I'm not exactly sure if that's the one I'd go with, but it seems applicable to both models. There is also the 40-18029, which could give you lower voltages with the lower tap, but it'll have a bunch of extra wires (not a fan of that). OT: There seem to be some different stories on the Bandmaster OT. The Super used a 4-ohm tap for its (2) 8-ohm speakers. The Bandmaster, of course, has (3) 8-ohm speakers. I believe at least some (all?) of them ran a 4-ohm tap as well, which was a mis-match to the speaker load ( 8-ohm speakers / 3 = 2.67R). It seems I've seen some folks suggest that there was actually a specially wound 2.67R OT tap, but I'm not sure. All that to say: at least some specimens of both the 5f4 and the 5e7 ran a 4-ohm OT. The difference was the speaker load, with the 5f4's (2) 10" speakers running at 4R each and the 5e7's (3) 10" speakers running at 2.67R each (assuming a 4-ohm OT). The OT on the Super schematic is listed as 45216. The Bandmaster schematic doesn't give a Triad number. I have read, however, that they both used Triad 1848. There are several current models that have the correct 6k primary impedance and multiple taps. The Classictone equivalent of 45216 on the 5f4 schematic is Classictone 40-18088, and it actually has 2.67R, 4R, and 8R taps: http://www.classictone.net/40-18088.html choke: It is well documented that a lot (if not all) the chokes that come in amp kits for the 5f4 and 5e7 (including Mojotone's) are woefully underspec'd for the current. Given that the schematic for both the Super and the Bandmaster puts the choke before the power tube plates instead of after them means that the choke would need to be spec'd for 200-250 mA (the Mojotone one that comes in the kit [MOJO 777] is spec'd at 3.5 Henries of inductance and 100R resistance, but only 100mA of current!). Again, Classictone makes a choke that looks like it would do a much better job with the current, though I don't know what difference the inductance and resistance specs make to the performance: Classictone 40-18058 is rated for 250 mA of current, 3H of inductance, and 125R resistance. Hammond 159S is rated for 225 mA of current, 4H of inductance, and a resistance of 65R. I'm sure there are others, and I'm planning to keep the choke before the plates rather than move it after the plates (at which point a smaller choke would be fine, though one would need more filtering of the B+ with the caps). What is the difference in inductance and resistance between these two filter chokes, and how do those specs compare with the choke or chokes used in the 5e7 and 5f4? 3. So this is what I'm driving at: I love the sound of the Bandmaster, and it seems to be prized by others. I think I'd like the 5f4 Super, but I don't know. And it doesn't seem to be as well loved in terms of Fender tweeds as the 5e7 is (and the fact that the 5f4 was supposedly one of Leo's favorites suggests to me that its reputation for higher headroom, longer clean, and brightness is correct; that's what he liked). Could I simply use a 2x10 configuration like the Super and get close to the Bandmaster tonality? I know that the third 10" speaker will add a great deal to the sound of a Bandmaster, in comparison to a Super, but is the magic of the Bandmaster versus the Super really only (1) 10" speaker? How important is the impedance mismatch in the Bandmaster sound? Though the Classictone OT listed above actually includes a 2.67R tap, it would seem advisable to stick with the 4R tap to me. Am I wrong? Except the one resistor listed at the first of the post (4.7M versus 10M), it sure seems it would be easy to build a 5e7 using a 4-ohm OT that would run either (2)-10" speakers on a 4-ohm load each or (3)-10" speakers at 2.67 ohms each. But it sure seems to me that there must be more to the difference in sound between these two amps... In the end, I'd rather have the portability of the 5f4 if I can get close to the sound of a 5e7. I'm wondering out loud how different the 5f4 and 5e7 really are. Either way, I'm planning on running a pair of vintage Tung-Sol 5881's and a 5U4 rectifier. Thanks for listening to my long-winded explanation and my questions!