They aren't that different from tweed Fenders but they really are different sounding. Yesterday Lou Rosano came over with my new Louis Electric JTM45 style and a new 412 cab and a 100 Watt plexi style he made for another customer. The guy that wound the speakers (Jim) also came over. So in trying out the 412 (which are these hand wound greenback style speakers) we compared the JTM45 style with the tweed Twin style head Lou built for me a couple years ago. They aren't that different a circuit, but man they sound different. I totally prefer the tweed Twin style, but the JTM45 style has that Marshall sound. Sounds like early Clapton (no surprise there). Then we compared the Germino Headroom 100 to Lou's 100 Watt plexi version. All of this was at high volume in the living room complete with the rest of the family going out up by the barn and passing remarks about the windows shaking and stuff. So we really let these amps stretch out, as opposed to using my cab in the isolation room that I usually use. It was actually surprising to me how different the Germino Headroom 100 was from the Louis Electric 100 Watt plexi style. Yeah, old Marshalls varied a lot, and these are two amps that are supposed to be old Marshalls built right. Lou had a special copy of a Drake output transformer in his version and the Germino has a different transformer. The Germino was much rounder and smoother, and had less sustain. The Louis Electric was hairier and hotter in the upper mids and it has sustain for miles. We did quick A/B between the two heads. We all heard the same thing between the two amps. I liked the Germino tone more and the Louis Electric sustain more. Lou thought about revoicing the Louis Electric, but I think he's just always revising his work - there was nothing bad about that head. Jim made the comment that Ken Fisher would not think the Germino sounded like a good plexi. Apparently they know Ken Fisher, and his ideas about how a plexi should sound. I don't know. The Germino has a big muscular sound which is round and thick. It's got more sag that the Louis plexi and much smoother. It's like the Germino had the compression on the leading edge of the note and the Louis had the compression on the trailing edge. The Louis had much more of the hairy aspect and somewhat more buzz in the tone. Sounded slightly modern. I don't know if I could make the call which was better in general. It would depend a lot on what style you played. But to my ear the Germino had better tone, although it could use a tad more sustain in comparison. The Louis plexi is made for another customer who is going to sit in with a very loud band in a big venue which is why he wants the 100 Watts. When Lou is done revoicing it for the customer it will probably be different than what I heard. Finally Jim had never come across a Dumble, so we plugged that in the cab. They mostly were trying to figure out whether they can make an amp that people would pay $30,000 for. Jim suspects that the output stage has positive feedback. I'm mildly surprised by that but it is not out of the question - you would just have to filter it to keep the amp stable. Dealing with Lou is a pleasure, and I love his tweed Twin-ish head (an astonishingly good amp), and the JTM45 style is a solid amp.