What does a SLO100 a 5150 and a Marshall have in common? (Honest question, not a setup for a joke!)

[HFloyd]

SOOOO.

Recently I've been sorta rabbit-holing on how amps are "related" to each other. One thing that keeps coming up is that Soldano SLO100 preamp which seems to be in basically every high gain amp. Specifically in a Recto and a 5150, but I also strongly suspect that the same preamp is in a Bogner Uberschall based on the fact that my Recto can do a pretty decent impersonation of the Uber (not the same, but...close enough that you probably wouldn't tell the difference when blasted out of a shit PA).

I was playing my 5150 Iconic yesterday and having a blast because it's a great amp, but I started to notice that it kinda felt surprisingly Marshally. Which in hindsight, makes an awful lot of sense considering that EVH was very much a Marshall guy (trying hard not to invoke that guy who makes EVH threads non-stop...)

Which has lead me to the above question.

I know a 5150 has the SLO preamp, but did Peavey effectively just bolt that to a JCM800 poweramp? Or a Plexi poweramp? Which is kinda what I thought a SLO100 was?

Basically, I'm curious how 5150s, SLO100s and Marshalls are all linked. Anybody got any ideas?

 

[StrummerJoe]

The 5150 Iconic is very different from an SLO100. James Brown was going for the earlier VH tones in that amp.

The Peavey 5150 and Boogie Rectumfryers have a lot in common with the SLO preamp.

I don't see the SLO having much in common with most Marshalls due to most of the drive coming from the preamp and attainable at much lower volumes than with most Marshalls that need volume to get to the sweet spot.

 

[playloud]

Looking at the schematics is the best way to distinguish between them. These high-level "topological" characterizations get repeated on forums and spread around like gospel truth. They only really make sense if you have a reasonable understanding of circuits in the first place.

I'm not an expert on the various 5150s and their channels, but I suspect the similarity is in the large number of gain stages (4+) and the use of a 39k cold clipper (as in the SLO-100).

The SLO-100 has 4 gain stages (one with a 39k cold clipper, so not much gain in practice - but plenty of assymetrical clipping) and a CF tone stack. The most notable thing about the SLO-100 is how it dumps a lot of signal after each gain stage, so you get a "distorted signal" without the sort of amplitude that will overload the power amp and subsequent gain stages.

The Marshall 2203 has 3 gain stages (one with a 10k cold clipper) and a CF tone stack, so in that sense the SLO-100 could be considered a "continuation on a theme". This was designed on top of the 1959 circuit, which has 2 gain stages and a CF tone stack.

There are plenty of high-gain amps which take a different approach to the SLO. One of my favorites is the TW Express/Liverpool, which has only 3 gain stages (plate-drive tonestack), with the last one being a (10k) cold clipper. Another one to look at is the Silver Jubilee, which inspired Wizard Amps (note use of clipping diodes). The Jose-modded Marshalls are also interesting. And don't forget the OD channel of the Dumble Overdrive Special - another take on a 4 gain stage design.

 

[guitarbilly74]

preamp, but did Peavey effectively just bolt that to a JCM800 poweramp? Or a Plexi poweramp? Which is kinda what I thought a SLO100 was?

Basically, I'm curious how 5150s, SLO100s and Marshalls are all linked. Anybody got any ideas?

Yes kind of.

This is the lineage of the 5150: Peavey first released the Butcher in 1983, which is a copy of the JCM800 only with 6L6s in the power amp.
Then in '86, they released the VTM.. The VTM was the Butcher platform, but with some mods that were done by Jose Arredondo to a Marshall owned by guitarist Marc Ferrari from Keel. They copied all the mods and put them on DIP switches in the VTM front panel so you could turn them on/off individually.
Then when Eddie joined Peavey, he liked the VTM but wanted the preamp to be based on the SLO.

But the power section remained the same throughout all these evolutions.

So in short, the original 5150 traces back to the VTM, which traces back to the Butcher, which is an 800 copy.

 

[HFloyd]

Looking at the schematics is the best way to distinguish between them. These high-level "topological" characterizations get repeated on forums and spread around like gospel truth. They only really make sense if you have a reasonable understanding of circuits in the first place.

I'm not an expert on the various 5150s and their channels, but I suspect the similarity is in the large number of gain stages (4+) and the use of a 39k cold clipper (as in the SLO-100).

The SLO-100 has 4 gain stages (one with a 39k cold clipper, so not much gain in practice - but plenty of assymetrical clipping) and a CF tone stack. The most notable thing about the SLO-100 is how it dumps a lot of signal after each gain stage, so you get a "distorted signal" without the sort of amplitude that will overload the power amp and subsequent gain stages.

The Marshall 2203 has 3 gain stages (one with a 10k cold clipper) and a CF tone stack, so in that sense the SLO-100 could be considered a "continuation on a theme". This was designed on top of the 1959 circuit, which has 2 gain stages and a CF tone stack.

There are plenty of high-gain amps which take a different approach to the SLO. One of my favorites is the TW Express/Liverpool, which has only 3 gain stages (plate-drive tonestack), with the last one being a (10k) cold clipper. Another one to look at is the Silver Jubilee, which inspired Wizard Amps (note use of clipping diodes). The Jose-modded Marshalls are also interesting. And don't forget the OD channel of the Dumble Overdrive Special - another take on a 4 gain stage design.

This is the sort of information I'm looking for. I remember when I first got my Recto people would tell me all sorts of things about what it is. "Bro that's basically a Mark IV mixed with a Marshall!" and "Yeah nah man it's got no Marshall AT ALL in it" and "Pfft, it's just a Fizzy JCM800" so yeah I'm after sorta historical "development" timelines as to what-came-from-what and actual circuit information.

Yes kind of.

This is the lineage of the 5150: Peavey first released the Butcher in 1983, which is a copy of the JCM800 only with 6L6s in the power amp.
Then in '86, they released the VTM.. The VTM was the Butcher platform, but with some mods that were done by Jose Arredondo to a Marshall owned by guitarist Marc Ferrari from Keel. They copied all the mods and put them on DIP switches in the VTM front panel so you could turn them on/off individually.
Then when Eddie joined Peavey, he liked the VTM but wanted the preamp to be based on the SLO.

But the power section remained the same throughout all these evolutions.

So in short, the original 5150 traces back to the VTM, which traces back to the Butcher, which is an 800 copy.

This is also good shit!

So to generalise, a 5150 is KIIINDA a SLO100 Preamp attached to a Jose modded JCM800?

What's the deal with Rectos?

 

[tallcoolone]

I've had 3 5150 amps several Dual Recs and picked up my first SLO100 last year. IMO the 5150 is very compressed not my cup at all, the SLO much much less so. The Mesas are more up front, but the SLO has more top end and cut--almost like a Marshall but not quite.

 

[Dino Boreanaz]

I thought this video did a good explanation of the SLO circuit. I watched it after the same channel's videos explaining the circuits and evolution of the Bassman-JTM45-Plexi-JCM800 and it was at just the right level for my basic knowledge of amp circuits.

 

[guitarbilly74]

This is also good shit!

So to generalise, a 5150 is KIIINDA a SLO100 Preamp attached to a Jose modded JCM800?

Almost. The Jose mods of the VTM were all preamp mods so they didn't transfer to the 5150. But it's correct to say the 5150 is a SLO preamp with a few tweaks into a JCM800 power section.

I know the drive channel of original 2ch Recto is heavily based (i.e. copied) off the SLO overdrive channel. But frankly the rest of the amp (clean channel, loop, power amp) is quite different and pretty much its own thing.

 

[HFloyd]

I've had 3 5150 amps several Dual Recs and picked up my first SLO100 last year. IMO the 5150 is very compressed not my cup at all, the SLO much much less so. The Mesas are more up front, but the SLO has more top end and cut--almost like a Marshall but not quite.

Yeah while they all share a similar DNA, they're definitely still different. The Recto is sloppy as hell and I kinda hate it for rhythm, but it almost always wins for me if I'm recording some high gain lead. Saturates well, but it just sings.

5150s are weird. They have a huge amount of compression to the point where it doesn't really matter what guitar you plug into it 'cos it's just gonna make it all sound the same. Despite that, there's some Marshally bite to it that the other amps don't have? I don't know how they get huge compression, yet still a cool bite to it?

I thought this video did a good explanation of the SLO circuit. I watched it after the same channel's videos explaining the circuits and evolution of the Bassman-JTM45-Plexi-JCM800 and it was at just the right level for my basic knowledge of amp circuits.

Well this is what I'm gonna watch tonight! I'm very much not an electronics guy so I get the feeling this will teach me an awful lot.

Almost. The Jose mods of the VTM were all preamp mods so they didn't transfer to the 5150. But it's correct to say the 5150 is a SLO preamp with a few tweaks into a JCM800 power section.

I know the drive channel of original 2ch Recto is heavily based (i.e. copied) off the SLO overdrive channel. But frankly the rest of the amp (clean channel, loop, power amp) is quite different and pretty much its own thing.

See, this is where it's interesting to me.

'Cos I saw this video:


And thought that the Uber\JCM800 sounded KINDA similar. The Uber saturates way more but the voice was KINDA similar. So that lead me to ask my amp tech mate about a JCM vs an Uber and he said that the Uber was BASICALLY a JCM800 with a Soldano Preamp.

I mean we know from pedals that changing a few parts can sometimes have a massive impact. It definitely wouldn't be fair to say that these amps all sound the same even if they have the same DNA but...they ARE kinda similar...and kinda different at the same time. If you listen carefully you can hear my brain spinning trying to sort this out.

 

[HFloyd]

Y'know.

It's just occurred to me.

That Eddie Van Halen - Master of tapping.

Would probably fucking love an amp that had a shitload of compression in it.

 

[JSutter]

The early Rectifier ads described it as a souped up Marshall. Pretty crazy considering the later revisions turned into something else.

 

[HFloyd]

I vaguely remember hearing that Mesa wanted the Recto to be the "Hair Metal" amp of choice, but they kinda took too long in developing it so it came out in the early 90s and missed the boat.

But it was a great sounding amp anyway and just ended up being adopted for metal in general.

 

[PentodeLicious]

The 5150 is a copy of a SLO with some minor component differences in the preamp and a 120W output section.

The SLO is "inspired" by mesa boogie Mark Iic+ which its roots are from fender.

The recto has a lot of similarities to the SLO but it's a total different animal.

The one thing that all of them have is a cold clipper stage.
That is the key to that high gain sound "never" heard before.

So basically because everybody is ripping of everyone else I have no issue in enjoying my bugera 6262 which is a replica of the 5150II.
And to the original question there are more things in common to a fender princeton in these amps than to a marshall.

 

[V-man]

OT but I never got into Mesa/Rectos, quickly hating what “M” became and them becoming the next face of metal that became out of touch with. The BG info added just to say I had no interest in giving them a fair hearing (other than noting recs usually washed out in the live mix), thus my limited understanding of them comes very slowly over the years…

… But my point was to reference Kyle Bull who recently did a DR vid in the past year or two being reminded why he did not care for them at all. The takeaway was he revisited them and was floored by how “wrong” he was: until he got a second one. He solidified his bias by noting his experience was they were very inconsistent amps from example to example (think 70s Marshall, only rock ‘n roll is a lot more accommodating to a loose Marshall than modern metal is an off-Rec).

A minor detour but if accurate, perhaps one of the more noteworthy deviations from the “consistent cousin” made by Peavey.

 

[rmlevasseur]

I cant speak about the internal difference, but it is very hard for a SLO to sound brownish or like a plexi. My Origin 20 actually does a better VH1 than my SLO. In order to get close on my slo I have to use the crunch channel and get the presence and bass very high. I have to juice the front end with a clean boost as well.

 

[PentodeLicious]

OT but I never got into Mesa/Rectos, quickly hating what “M” became and them becoming the next face of metal that became out of touch with. The BG info added just to say I had no interest in giving them a fair hearing (other than noting recs usually washed out in the live mix), thus my limited understanding of them comes very slowly over the years…

… But my point was to reference Kyle Bull who recently did a DR vid in the past year or two being reminded why he did not care for them at all. The takeaway was he revisited them and was floored by how “wrong” he was: until he got a second one. He solidified his bias by noting his experience was they were very inconsistent amps from example to example (think 70s Marshall, only rock ‘n roll is a lot more accommodating to a loose Marshall than modern metal is an off-Rec).

A minor detour but if accurate, perhaps one of the more noteworthy deviations from the “consistent cousin” made by Peavey.

Kyle bull... don't get me wrong he looks like a really kind and sweet person but regarding to his recording capabilities I have doubts.
His micing is bad and the sound of all the amps he records sound thin.
I know this because he tested around 4 amps that I own and at least 10 others I heard in person...

This is how a dual rectifier actually sounds(skip to 0:55):

 

[SonVolt]

^^^^ that's certainly how a Recto can sound. Maybe it's the Greenbacks in that cab, but it sounds overly mushy/fuzzy. I think V30s really help push the mids forward. Also, the "trick" of setting the Treble to 0 and putting the Mid on 10 really opens the amp up.