XTC, 5150, and SLO: how different are these amps?

ElKabong

Member
I think many folks have heard, over the years, that the Soldano SLO-100 has been "copied" or "ripped off" by any number of amp builders. Personally, I've read folks claiming that EVH instructed Peavey to clone his SLO for the 5150 amp. I've similarly heard that Mr. Soldano felt Mesa had ripped off his design in building the Dual Rectifier. I guess I can hear the family resemblance in the 5150 (it has tons of pre-amp gain and can sound fizzy unless you get the poweramp really cranking); but I always associate Rectos with a woolier, looser sound than the SLO.

And since they are all available in the Axe III, I'm wondering, in the opinion of those who really know amps (I'm hoping Cliff can chime in here if he likes), how close are these amps? If they are, indeed, heavily based on the SLO, to what can we attribute the differences in their tones?

Finally, how different is the SLO from my personal favorite, the Bogner XTC?
 
Do you mean as far as their underlying circuit designs? They definitely don’t sound the same.

In a circuit, a single resistor value can have an affect on tone. It doesn’t take much tweaking to end up with something that sounds different.

However, when people suggest that Mesa or Peavey “copied” an SLO, it’s my understanding that it was more that they implemented some of the high gain circuit concepts rather than actually cloning anything in particular. In the end, they’re all tube amp circuits. They’re inherently similar.

Full schematics are available online for most tube amps. Even if you don’t know how to read them exactly, you can kinda get a rough idea of the differences in circuitry by comparing a few.
 
Dual rectifier preamp is a copy of the soldano slo but different power amp obviously so they sound different.. 5150 is similar but with a 1 more gain stage.. Bogner xtc great amp and versatile.. Tone wise is a personal choice.. Between bogner and soldano don t forget the pick attack response.. I asked some days ago and cliff replies saying bogner has low pick attack response.. I can confirm this.. If you re a fast solo player could not be the best choice.. For me soldano the best ever.
 
Guitar amps all borrow from one another in some way, and it could be said the SLO was derivative of the amps before it, including earlier Boogies, Hiwatts, and similar "over-engineered" circuits. In the end, they all do their own thing, and speak to different people and styles of playing. You'd be hard pressed to differentiate between similarities and copying in many designs. It's almost like legos... same parts, different ways of putting them together.
 
All three are pretty much modified Marshall Plexis which in turn are modified Fender Bassmans. Leo's designs were based largely on tube radio amplifiers and tube manual circuits of that time. It's been a constant evolution since the 50's. Just depends on how picky you are and who you want to blame.
 
I can say having played 3 of these and owning an SLO 30, I can certainly hear the recto vibe in the SLO. Sounds like a slightly tighter recto with a tone stack (or at least the mids knob) that is a bit more upper mids then the recto I played/owned. Sounds nothing like a 5150 to me though.
 
I think many folks have heard, over the years, that the Soldano SLO-100 has been "copied" or "ripped off" by any number of amp builders. Personally, I've read folks claiming that EVH instructed Peavey to clone his SLO for the 5150 amp.
The 5150 has striking similarities to the SLO-100, but it's different enough that I don't think "clone" is the right word. I think the truth is Eddie went to Peavey and said "build me something just like this SLO-100, except I have some ideas for a few changes to the design.".
 
The answer, as always, is 42.
ASCII 42

In programming, an asterisk is commonly used as a sort of "whatever you want it to be" symbol, I've heard it called a wildcard.

ASCII language, the original way that computers run, the most basic computer software, in it, 42 is the designation for asterisk. The GIANT COMPUTER was asked what the true meaning was. It answered as a computer would.

Anything you want it to be.
 
ASCII 42

In programming, an asterisk is commonly used as a sort of "whatever you want it to be" symbol, I've heard it called a wildcard.

ASCII language, the original way that computers run, the most basic computer software, in it, 42 is the designation for asterisk. The GIANT COMPUTER was asked what the true meaning was. It answered as a computer would.

Anything you want it to be.
You win two Pan Galactic Gargle Blasters!
 
I don't know anything about the technical side of amps, but Cliff has stated before that the Rectifier copied the SLO preamp. I'm sure you can dig those up with a search. I don't know how valid the 5150/SLO comparison is.

To me those amps don't sound alike and they fulfill totally different tones and playing styles. 🤷
 
Quite Everything is about copy + improvements . But a rectifier is not a slo 100 whatever they can say . So maybe he copied something but I like the recto and don’t like the soldano at all so ... nice job Mesa 😅👍🏻
 
I think many folks have heard, over the years, that the Soldano SLO-100 has been "copied" or "ripped off" by any number of amp builders. Personally, I've read folks claiming that EVH instructed Peavey to clone his SLO for the 5150 amp. I've similarly heard that Mr. Soldano felt Mesa had ripped off his design in building the Dual Rectifier. I guess I can hear the family resemblance in the 5150 (it has tons of pre-amp gain and can sound fizzy unless you get the poweramp really cranking); but I always associate Rectos with a woolier, looser sound than the SLO.

And since they are all available in the Axe III, I'm wondering, in the opinion of those who really know amps (I'm hoping Cliff can chime in here if he likes), how close are these amps? If they are, indeed, heavily based on the SLO, to what can we attribute the differences in their tones?

Finally, how different is the SLO from my personal favorite, the Bogner XTC?

I have all the amps that you mentioned and no matter how much they're copied they don't sound the same.

I know that the Dual rectifier is the same only in the preamp layout while different in the final stage (i.e. the tube/silicon rectifiers and a more spongier bass response). While the 5150 is the same but adds another preamp tube to the layout. The power section is different and components also (Soldano has DeYoung PT) Anyway the SLO is more Hi-Fi and elegant sounding and way less extreme than DR or 5150 and while is still plenty of preamp gain it's never fizzy or harsh.

As different they sound in the room, when they're miked, anyway, they still retain some kind of familiarity: that's why there's plenty of videos that purport to suggest that they sound identical and therefore there is no difference between a $ 4000 SLO and a $ 1,200 EVH 5150. And that's simply not true. Differences are also in pick response and attack, resulting in a more 2dimensional sound of the 5150 (which I love anyway).

As for the Ecstasy is a world apart especially for the possibility of shaping your favorite sound. It has a unique crunch sound (blue channel) that is completely different from all the others amps. Perhaps one of the most beautiful sounds ever. But for some reason I don't tie much with the soft attack and a compressed feel of its hi gain sound on (red channel).
 
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Circuits? I look to others. I've never confused one for the other when playing them.

The Mesa has the low end push, the Peavey the midrange clank, and the Slo has more squish and feels more even across the EQ.
After mixing and mastering any can sound like any though, so if you are only going by recordings, you'd never know.
 
The Mesa Dual Rectifier Solo amp (as it was originally called before the other Dual Rectifier amps flopped and they pretended the Solo amp was the only amp in the Dual Rectifier line) was almost a component for component copy of the SLO-100 preamp in the early days. Even the name (Solo vs SLO) is similar. They used much weaker output transformers, the switchable tube rectifier, and the modern mode negative feedback removal circuit all of which helped give them some character all their own. And they kept iterating the design from there from RevA to RevG, then 3 channel, then multiwatt. The oldest early revision models models are usually referred to as tighter, less bassy, and thrashier, which sounds a little closer to the SLO sound to me too.

Now seeing as the Solo was just one of 4 Dual rectifier amps where the switchable tube rectification was the real star maybe they didn't feel bad about lifting some other amp designs. And then it accidentally turned into the most popular amps of the 90s.

The original 5150 shares enough similarities that It's reasonable to believe they had a SLO on hand to reference while they were designing it too.

All that said, go into advanced settings on the Axe FX and start fiddling with Negative Feedback, Input EQ, and more and you'll see how a few small changes can affect the overall character and sound, which is part of why these "copies" all sound and feel pretty distinct.
 
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