Up front: Im no amp builder, and Im really in awe of so many of you guys that know your shit SO deeply on the internals of an amp. I build and play guitars, and I've never found the time to even start on the 50 watt Plexi kit (the first one MetroAmp ever sold) that I bought so long ago. I finally conceded that I WASN'T gonna find enough time to build it, and I didnt wanna F-up a nice kit for my first, so I sent 'er back to have Jim at MetroAmp build it.
Well, its been a few months having my Metro 50 watt Plexi make the trip to Burton MI (twice) to be built, tweaked, and tranny-swapped by the good 'ol boys at MetroAmp. (Jim and Dave... MONDO props to you guys for all your help and advice).
The amp started life as a '68 Bass spec, but was nowhere near aggressive enough for my tastes. A local amp tech stuck his hands in there, modifying it to be much more aggressive while still retaining the fatness of the original Bass spec. Currently, I'd call it a modified Lead/Bass spec. Its played thru a Marshall Mode Four cab loaded with a quad of old, original G12-65's. With an original LP, I was looking to nail Duane Allmans tone from the Fillmore recordings. I did NOT want a clean sounding 50 watt--I wanted an aggressive screaming '71 metal-front era animal. Circuit-wise, ultimately I got exactly what I wanted.
Against Metro's initial advice, I opted for Mercury ToneClone iron for the PT, OT and choke, figuring Mercs HAD to be the best choice in a custom amp like this.
(Note to self: LISTEN to an experts advice, and DONT think you know more than someone that does this shit for a living, cause ya dont).
Well, out of the box (and after the aforementioned aggression modding) with the Merc iron, the amp sounded GREAT... solid as concrete bottom end, superb, crisp definition, awesome note separation, and a singing, liquid sustain that raised the hair on the back of my neck. The amp had a lot of touch-sensitivity, easily cleaning up with lighter pick attack or simply rolling back on the guitars volume. And it SCREAMED in both channels, with the "Normal" channel having a fat-ass bottom end and later break-up than the "Bright" channel, which was overdriven into sustain by the time the volume was at "2" or better. Set the Normal to the desired volume and fatness, set the Bright to add crunch to taste, and wail away like a mo-fo.
Sounds perfect, right?? No. The one thing this amp lacked was ANY sag, or resemblance to "vintage" anything. LIGHTNING fast pick attack (it sorta reminded me of a Soldano in that way), and to my ear, upper-mids that didnt remind me of any Marshall I ever heard. They didnt sound necessarily BAD, just kinda hard, and Mid was a control that basically stayed off, or very low at best. Bottom was SUPER solid and ballsy and shook the glass in my house. Top end was sweet and intense at the same time. VERY cutting. Not vintage in the least.
Lots of phone calls!! Mercury says its not the trannys. Metro says it IS the trannys. What to do?? Brought it out again to my good bud in Medford, N.Y. (Richie Johnson, the aforementioned other tech... gotta give props where they're due). Richie knows Marshalls like NYC knows pollution. He tweaked the circuit a bit, added a pot on the NFB, and virtually TOLD me that despite the mods, the "problem" is in the trannys.
Its a very tough decision yanking out expensive iron like Mercs for Heyboers, (even though Im being told they're "Metro-spec" Heyboers, and have nothing to do with off the shelf Heyboers). But the bottom line was that I was beginning to not like the amp, NOT because it sounded "bad" (cause it didnt), it just didnt sound "RIGHT" for my needs at all. I already have "fast", modern sounding amps. I didnt need another one.
Well, amp road trip #2 to Michigan, this time to bite the bullet, concede to what everyone is telling me, and have the Mercs yanked out, and the Metro-Heyboers (along with the Metro choke) installed.
Get the amp back, re-install my beloved Brimars and Mullards, biased it up and plug it in, VERY suspect that there will be any improvement. In fact, I expected to be disappointed.
(Read note to self... again).
Whole different ballgame ALTOGETHER. Not the same amp AT ALL, right out of the box. It still works the same, circuit wise, in that its a goggle-eyed screaming animal at almost any volume settings, but this sucker sounds EXACTLY like a '71 Marshall built on the best day the assemblers at Marshall ever had EVER. NOW its got guts, balls, cut, sizzle, and the EXACT amount of sag an old Marshall would and should have... I hate to use the word perfect, but its PERFECT. Playing my LP without a pick yields the most dead-on Duane tone I've ever heard, short of the Fillmore recordings of Duane himself. If it was a vintage amp in a store for sale, I'd buy it at $500.00 above the current market price without hesitation. Its THAT good.
Years ago, I played thru a '71 metal front that sounded like God built it, and I've been searching for that tone ever since. This amp is better. Yep, better. Not only does it SOUND better, but Im sorta freaking out about it cause its THIS good, and its brand new. There are a few non-conventional items in there (like the adjustable NFB pot) and a cap or two. But, to my ears, and to how many tweaks this amp has had to get it to this point, the VAST majority of this amps tone IS the Metro-spec trannys. There is a REALLY big difference between the Metro heyboers and the Merc ToneClones. Neither is bad, actually both are great... they're just both really, really different.
If anyone wants to see a gut-shot, lemme know and Ill post it. Just dont ask me WTF this or that is, cause as I said, Im not an amp builder. Probably most of it will look stock, with the exception of the caps used to make it more Lead spec, and the bright volume cap is a .0047 Orange Drop, not the stock Silver Mica. It was universally deemed better sounding, though not stock Marshall spec.
Anyway, maybe this might help someone out there thinking about swapping the trannys on their 50 watt. I've read some threads about other iron, like Magnetics Corp, etc. I cant speak for them, and Im sure they make a great product too. This has been MY experience between Mercury ToneClones and Metro Heyboers.
Thats the long and short of it... kinda expensive, but at this point, impossibly sweet... just like Duanes tone!!
). My pleasure. Here are some gut shots, as promised.
)
), but Im happy as shit with it now. I wouldnt change a thing on it.
. Been sitting on it for weeks waiting for the right opportunity. I'm real slack when it comes to my own amps. 
