My SLO100 Sounds Like a JCM800
- Thread starter Deadpan
- Start date
Badonkey Kong
Roadie
- Messages
- 262
Let's hear it!
MirrorProfiles
Rock Star
- Messages
- 3,242
it’s definitely 2203 derived. infamously swaps the 10k cold clipper with the 39k cathode resistor.
more low end filtered out of the pre (with extra gain to keep it tight), makes up for it by adding the low end back later in the circuit.
there’s a cool explanation of the circuit here:
more low end filtered out of the pre (with extra gain to keep it tight), makes up for it by adding the low end back later in the circuit.
there’s a cool explanation of the circuit here:
- Messages
- 4,411
Therefor, recto = jcm800
James Freeman
Rock Star
- Messages
- 3,672
I hereby declare that henceforth a stock '80-'82 JCM800 2203/4 shall be the benchmark amp to which all amp modelers and plugins be judged and graded in accordance to how accurately they emulate this amp.
So it is written, so it shall be done.
So it is written, so it shall be done.
the-trooper
Shredder
- Messages
- 1,881
Elric
Roadie
- Messages
- 699
Rectifier == JCM800
SLO == JCM800
Helix has a Rectifier
Helix has an SLO
Helix has not one; but two JCM800s.
JiveTurkey
Goatlord
- Messages
- 16,447
laxu
Rock Star
- Messages
- 5,371
With the Revv models arriving on Fractal the other day, I set up a little comparison preset between Cornford MK50, Diezel VH4 and the Revv models. They honestly weren't that far off from each other, like I could have probably spent more time and gotten them fairly close with vastly different EQ settings and picking one as a reference. I got far bigger differences out of each by just swapping between cabs.
To me this translates to the real world rigs too. When I had the Vox AC30-ish Victory VC35 and the Fender-meets-Marshall Bogner Goldfinger 45 SL, if I ran both of them into the same 4x10 with 10" Greenbacks the Victory ended up sounding far more Marshallish than if I ran it into a 1x12 with an Alnico Gold which brought in that Vox style chime.
People keep buying more amps because those are more exciting, but in reality would be probably better off buying more cabs.
To me this translates to the real world rigs too. When I had the Vox AC30-ish Victory VC35 and the Fender-meets-Marshall Bogner Goldfinger 45 SL, if I ran both of them into the same 4x10 with 10" Greenbacks the Victory ended up sounding far more Marshallish than if I ran it into a 1x12 with an Alnico Gold which brought in that Vox style chime.
People keep buying more amps because those are more exciting, but in reality would be probably better off buying more cabs.
James Freeman
Rock Star
- Messages
- 3,672
Very true for high gain amps especially when they are level matched.
Low-mid gain amps when they have up to 30dB difference in frequency response due to tone shaping in the preamps is a different story in my experience.
Coalface1971
Groupie
- Messages
- 99
Owning both amps at one point (still have the SLO, stupidly sold my '76 2204), having other 800-style amps, comparing the SLO's lead channel to the stock 2203/2204 is not a fair fight.
There is an extra gain stage, different stage biasing, more bass, more filtering, FX-loop in circuit, and a 39k cold clipper sounds a different to a 10k cold clipper (I've pissed around with the cold clipper value in 800 circuits). Needs a modded 800 or some type of pedal to make that a worthy comparison. Even then, the SLO's power section is still punching hard, when the Marshall's is a squishy mess (which is cool, btw).
The cold clipper 39k in the SLO (not pointed out in Robinette's article, I don't think?) is not in circuit on the SLO's rhythm channel, so comparing the 800 to the SLO crunch is closer to comparing the Marshall to a stiffer (highly filtered) and more bass heavy, cascaded JMP MV. The SLO is cleaner, and clearer maybe, but also not as much fun with the spandex pants.
Sorry guys, Randy ripped off the SLO for the Recto
There is an extra gain stage, different stage biasing, more bass, more filtering, FX-loop in circuit, and a 39k cold clipper sounds a different to a 10k cold clipper (I've pissed around with the cold clipper value in 800 circuits). Needs a modded 800 or some type of pedal to make that a worthy comparison. Even then, the SLO's power section is still punching hard, when the Marshall's is a squishy mess (which is cool, btw).
The cold clipper 39k in the SLO (not pointed out in Robinette's article, I don't think?) is not in circuit on the SLO's rhythm channel, so comparing the 800 to the SLO crunch is closer to comparing the Marshall to a stiffer (highly filtered) and more bass heavy, cascaded JMP MV. The SLO is cleaner, and clearer maybe, but also not as much fun with the spandex pants.
Sorry guys, Randy ripped off the SLO for the Recto
MirrorProfiles
Rock Star
- Messages
- 3,242
Coalface1971
Groupie
- Messages
- 99
Thanks man, I was just being lazy (it's early here). Faster for me to read the actual schematic than read RR's article again (had the SLOClone schematic up which is lovely CAD redraw compared to Mike's original).
MirrorProfiles
Rock Star
- Messages
- 3,242
your description was spot on and concise for the differences between the circuits!
- Messages
- 4,411
Sorry guys, Randy ripped off the SLO for the Recto
And bless him for that
I can afford rectos
Coalface1971
Groupie
- Messages
- 99
Any of the boutique amps are expensive in my neck of woods. Mesa' are as bad as Soldano, or anything BAD like Freidman etc.And bless him for that
I can afford rectos
MirrorProfiles
Rock Star
- Messages
- 3,242
History suggests he not only did the right thing, but he also massively improved it. SLO’s are beautifully built and it’s a historically significant circuit. But they have some odd design choices (FX loop, not an amazing clean channel).And bless him for that
I can afford rectos
Mesa found a circuit that they could build in HUGE numbers and that defined at least one (if not more) generations of rock music.
Yes, they copied a lot of the preamp but there’s tons of stuff in a Rectifier that has nothing to do with an SLO (tube rectifier, voltage drop, channel cloning, better fx loop, evolution with distinct channels and modes/cloning, totally different power amp). The Mesa Oversized cab that goes with it is one of the best cabs ever made too. Rectifier wouldn’t have happened without the Soldano but IMO the rectifier has had a way bigger impact on music
Last edited:
shanesiegle
Roadie
- Messages
- 127
I went thru 25 plus amps and once I dialed them in they were all more alike than not.
- Messages
- 1,325
Same cabinet I assume?
