rootz wrote: ↑Fri Aug 14, 2020 2:16 pm
norburybrook wrote: ↑Thu Aug 13, 2020 3:24 pm
p.s. Rootz, yes the 2x12 is a great cab I have one with two vintage G12-65's. It's big and heavy though. Have you tried the sealed ported 1x12 EVM 12 like the Carlton cab? They have a nice punch to them.
If breaking in of electrical components is a real thing, there is some good news. I have yet to read an article, comment or opinion where breaking in leads to worse sound reproduction! I can't really comment on it being a true thing or not. There is, like Martin and Tony said, no scientific research on many of these topics that I know of. Lack of research doesn't mean it can't be true though, just that it isn't researched before and you will have to trust your and others ears, logic and experience. In any way it is a highly subjective matter with some objectified arguments.
A few things to consider as far as iron goes: I recently built an amp that had brand-new defective output transformer. Made maybe ten watts, while it was supposed to be a 40-watt amp. During the diagnosis (of-course suspecting the transformer the least likely suspect), I realized how much unhappy power tubes can affect the grid drive. I tacked-in my test mule transformer (an old Bandmaster output with clip leads) and the amp was fine...but I kept thinking I had a driver problem someplace, because the power tubes were driving a bad transformer and the grids loaded the PI down..the whole output stage certainly works as a unit. I do agree, replacement iron can be all over the map. I like the Classic Tone stuff. Bogner uses it (although he puts a Bogner Custom Shop sticker on them, lol), Heyboers are good as well. Mercury is good at cloning, I've lost faith in them for new designs, as Sergio made a few errors he insisted were "for tone", but getting 60 watts from 4-6L6's at 500 volts due to mismatch is hardly a tone I would sacrifice 50% of my output for.
As far as break-in: I was never a big believer, but I started breaking in amps during burn in with the radio and a dummy load. My main rig is an Overdrive Supreme from the early 2000's. It's been loaned out to artists, gigged hard, and sings like a bird. I play brand-new amps daily, and while they are great, you can feel the organic warm "I want to be your partner" feel that this amp gives me. It's heavy as hell (Delta Pro speaker, and big iron), so I use a prototype hybrid mini combo with a Neo speaker 95% of the time now, but with over 15 years of playing behind it, the rig is stellar...now, to replicate that in the lab...oy.
As far as ODS-II and multichannel platforms: It's not impossible, just don't overthink it, and you can certainly make it work...
It takes a pile of relays and careful everything... but it can be done obviously. Les Paul once said "I told Gibson how to build a guitar, just not MY guitar". Same here...I give back what I can, when I can. The one tip I'd share is not messing with relay switching at the input jack. It's really quite tough to keep quiet. Do your switching later on...at higher signal levels and at a lower impedance signal point. FWIW: The Carol-Ann amps are a D-style (with a Marshall twist), and since Alan closed up, I've serviced and tweaked a fair share. One of his amps is pretty cool and is basically an HRM with the normal tone stack on top in channel one, that stack is bypassed (gain boost like a Dumble), and the second stack (HRM stack) on front panel serves the overdrive channel. Not a bad way to get "two channels" so to speak.
As far as Dumble comparisons to modern amps: Look, guys like Brandon and Jelle do their thing and do it well. I built maybe a dozen visual and electrical clones (pc boards though, sorry), that looked and sounded good enough that a local vintage shop asked me to take my amp out of the store (selling for $ 8-K) because it hurt his ability to sell the two real Dumbles he had in the store. I really didn't want to be another cloner in a sea of cloners. I have made a few at the request of a few specific clients, but it's really not my thing. The sales associate at the stores was comparing the two amps, and scratched his head for hours. "This is crazy, I can dial them in identically"....Yes, there are some amazing Dumble examples out there, and there are all the others. Howard had his share of bad days I'm sure, as I've seen, heard and played some amps that quite frankly, were not special at all. Many of us have seen that. If you don't think he had to make the rent and sometimes pushed things out the door to not get the police at his door, an angry attorney up his ass, or a customer banging on the door at 3-AM (oh, sorry Jackson, wrong door), you're fooling yourself.
A good friend had his Dumble repaired when he lived in the Abbey on Jackson Browne's property. He described walking down a hallway filled with Fender amps stacked as high as his head, from which Dumble took parts that he measured carefully and selected for their merits...and he rejected many as well...because of how he ran his "business" (as NOT a business), he never really had much custom made beyond the chassis and cabinets. That's why Radio Shack and other parts were used, where most builders would have a transformer wound to not need that extra transformer...he used stock everything really, and he made it work !
I chose to forge my path based on
what I wanted from an amp. Sure, started with a D-clone in a Bandmaster chassis, added reverb, added loop, fancied up foot switching, started refining things like DC tube filaments and PC boards when it finally got to the point I needed to be more consistent and efficient. Do they sound like Dumbles ? I lived with a Dumble Andy Brauer owned that was sent to me for repair. He had a rough year, closing Brauer rentals and personally, so I held onto it and it provided an opportunity for me to tune and compare and refine my amps to do many of the things people like that Dumble's do. The fact is, I no longer care about the comparisons, and am proud that I forged my own path that has influenced other builders (here and commercially too), which is flattering.
Have fun. Be safe, stay well, don't kill yourself, single point ground, be kind to others, and have more fun. Proud holder of US Patent # 7336165.
My list of things I still want to build keeps getting longer and longer! I have a design for a EVM12L based bass reflex cab. It is considerably smaller than the 1x12 I currently use. Care to elaborate what I could gain with a bass reflex over a half open 1x12 Marcus? 
...and drink rings on the suede 