Is the rectifier a copy of a SLO?

[67mike]

JCA are cool amps. Wish I still had my 22H, that was a real firey little guy after I swapped out all the stock tubes.

 

[Shask]

I have heard those JCA mods are cool amps.

I have a JCA100HDM that I modded completely into a SLO, and I also moved the loop to the normal spot and added a master volume. Thing sounds awesome, and also makes a great poweramp for other preamps.

 

[RedPlated]

I’d have to go through schematics again but there are some differences in the Rectifier preamp.

The difference I think of first is the 5000pf capacitor from B+ to ground off of the second stage plate resistor. Really cuts highs.

Recto also has a 20pf snubber cap from the second stage grid to ground.

Recto orange treble cap is 500pf vs 470pf in SLO. It does make an audible difference. And red channel treble cap is 680pf.

Rectifier has 30uF preamp filtering. SLO is 10uF.

Orange channel in vintage mode is closest to SLO. It adds negative feedback with a 47k NFB resistor. SLO has a 39k NFB resistor. Recto uses 8 ohm tap. I forget which tap the SLO is using but that can make a difference as well.

Modern mode lifts the NFB so it’s brighter, louder and more raw.

 

[fusedbrain]

I’d have to go through schematics again but there are some differences in the Rectifier preamp.

The difference I think of first is the 5000pf capacitor from B+ to ground off of the second stage plate resistor. Really cuts highs.

Recto also has a 20pf snubber cap from the second stage grid to ground.

Recto orange treble cap is 500pf vs 470pf in SLO. It does make an audible difference. And red channel treble cap is 680pf.

Rectifier has 30uF preamp filtering. SLO is 10uF.

Orange channel is vintage mode is closest to SLO. It adds negative feedback with a NFB 47k resistor. SLO has a 39k NFB resistor. Recto uses 8 ohm tap. I forget which tap the SLO is using but that can make a difference as well.

Modern mode lifts the NFB so it’s brighter, louder and more raw.

I was hoping you would chime in lol!
As that 5000pf cap goes from the B+ side of the plate resistor to ground, and is not connected to the tube side of the resistor, I was expecting it to be a B+ ripple cap, and not a high frequency snubber. I'll have to experiment with this.
The 20pf snubber is the other component I mentioned in my first post. The low pass filter created by the 470k resistor and the 20pf cap has a center frequency of 16.9Khz, so I considered it insignificant to the tone of the amp. Again, I'll have to experiment with this.
The craziest thing about the recto's in my mind is the total absence of negative feedback in modern mode.
As far as I know, every other high gain amp uses rather large amounts of NFB in the power section.
The recto's in modern mode have NONE, and it sounds F'n great!
Go figure....

 

[BABMusic]

Randall Smith said this year that he wanted to change the preamp section but everyone else at Boogie liked it the way it was with the power amp. So in other words, he didn't deny it and gave credit to Mike. I know that later on it did change more and more, but it still has that recto thing.

 

[RedPlated]

I was hoping you would chime in lol!
As that 5000pf cap goes from the B+ side of the plate resistor to ground, and is not connected to the tube side of the resistor, I was expecting it to be a B+ ripple cap, and not a high frequency snubber. I'll have to experiment with this.
The 20pf snubber is the other component I mentioned in my first post. The low pass filter created by the 470k resistor and the 20pf cap has a center frequency of 16.9Khz, so I considered it insignificant to the tone of the amp. Again, I'll have to experiment with this.
The craziest thing about the recto's in my mind is the total absence of negative feedback in modern mode.
As far as I know, every other high gain amp uses rather large amounts of NFB in the power section.
The recto's in modern mode have NONE, and it sounds F'n great!
Go figure....

Yeah that 5000pf cap does definitely cut high end out. I usually reduce the value. Too large for my liking.

The lack of NFB sure is wild sounding. I add a a NFB control that functions on orange/ vintage only. I use a decent sized pot so you get close to no NFB with the control all the way up.

 

[stephen sawall]

Mike offered to modify my Tremoverb 30 years ago. We talked about this back then. He mentioned he had borrowed from Mesa first. He didn't mention what he borrowed. He really liked the sound of the Tremoverb. Randy offered to modify my Tremoverb 10 years ago. He mentioned he was looking into copyright of sounds.
The Tremoverb is still stock. I have done more gigs with this amp than any otheŕ.

 

[mnemonic]

Gain pots also different value (does affect the tone, not just gain pot position for a given amount of gain) and the fixed high cut ‘presence’ I believe is still in place on both modes, vintage and modern.

No pre-tonestack loop also, I removed the pre tonestack loop on my jet city jca50, it did noticeably improve the sound in my opinion. Amp sounded deeper and punchier with it gone.

I have read people say Mike took things from the mesa mark ii to build the SLO, I think he mentioned it in the tonetalk episode if I remember right, I’m guessing what Mike means by that is the idea to cascade additional gain stages for higher gain, if you look at the schematics they don’t really have anything else in common other than being tube amps.

 

[Racerxrated]

Put a SLO in my hands and I can make it a tight bro it’s metal monster . I’ve done it . I don’t understand . Not saying you . Everyone says this but to me it’s easy af .

Rectifier AND 5150 are SLO copies ( to a degree, in the preamps). Eddie took his SLO that he bought (Mike wouldn't give him a free one, which irritated him) to Peavey and said "Make this!". Mesa had been working on their version a little after Peavey did theirs.

 

[S̷͖͑m̵͎͂á̵̺s̸͚̈́h̴̬̑]

Rectifier AND 5150 are SLO copies ( to a degree, in the preamps). Eddie took his SLO that he bought (Mike wouldn't give him a free one, which irritated him) to Peavey and said "Make this!". Mesa had been working on their version a little after Peavey did theirs.

That is probably one of Mike's greatest regrets. So much would be different if he just gave the diva what he wanted.

 

[LPMojoGL]

I have an SLO and Tremoverb.
I've had a few SLOs, and 6 different Rectos.
And a couple of PV 5150/6505s, and EVH 5150s.
They all have their thing, and their quirks.

Tone is subjective. The SLO is not the best amp for metal, tho it is more than capable.
It doesn't have the krang of a Marshall. It has a 90s vibe to the sound, imo. It's arguably one of the best amps for lead guitar, as is evident by the plethora of players that have used it on stage and in studios.

Some things aren't subjective.
Build quality of the SLO is by far superior.
Sound quality (clarity, noise levels) of the SLO is superior.

SLO is my choice if I could only have one, compared to 5150 or Recto. It's not even close. Every time I play it, every time anyone hears it, including those that have no clue about guitar gear...it is obviously a level above and never fails to impress.

 

[Shask]

No pre-tonestack loop also, I removed the pre tonestack loop on my jet city jca50, it did noticeably improve the sound in my opinion. Amp sounded deeper and punchier with it gone.

Yeah, when I modded my JCA100HDM into a SLO I moved the loop to after the tone stack. It took away some of that smooth compression it had and made it more dynamic and punchy.

 

[Exo-metal]

I have an SLO and Tremoverb.
I've had a few SLOs, and 6 different Rectos.
And a couple of PV 5150/6505s, and EVH 5150s.
They all have their thing, and their quirks.

Tone is subjective. The SLO is not the best amp for metal, tho it is more than capable.
It doesn't have the krang of a Marshall. It has a 90s vibe to the sound, imo. It's arguably one of the best amps for lead guitar, as is evident by the plethora of players that have used it on stage and in studios.

Some things aren't subjective.
Build quality of the SLO is by far superior.
Sound quality (clarity, noise levels) of the SLO is superior.

SLO is my choice if I could only have one, compared to 5150 or Recto. It's not even close. Every time I play it, every time anyone hears it, including those that have no clue about guitar gear...it is obviously a level above and never fails to impress.

Never played an slo but I'm getting great results tweaking the recto.

 

[anomaly]

Most definitely a multi-watt dual rec will rip the face off a slo… (If we’re talking brootalz) next level up for me is an Uberschall… I was always after a blend between 5150 & Dual Rec.. Found that in the Uber.

I don't find the Uber all that 5150'ish. It's got it's own thing going on.

The reason a Recto blends with other amps so well is because it's so scooped in the mids, so it leaves this big spot for a more midrangy amp to sit. Something like an Orange would blend great with a Recto.

 

[anomaly]

I have an SLO and Tremoverb.
I've had a few SLOs, and 6 different Rectos.
And a couple of PV 5150/6505s, and EVH 5150s.
They all have their thing, and their quirks.

Tone is subjective. The SLO is not the best amp for metal, tho it is more than capable.
It doesn't have the krang of a Marshall. It has a 90s vibe to the sound, imo. It's arguably one of the best amps for lead guitar, as is evident by the plethora of players that have used it on stage and in studios.

Some things aren't subjective.
Build quality of the SLO is by far superior.
Sound quality (clarity, noise levels) of the SLO is superior.

SLO is my choice if I could only have one, compared to 5150 or Recto. It's not even close. Every time I play it, every time anyone hears it, including those that have no clue about guitar gear...it is obviously a level above and never fails to impress.

All that said, the recto practically defined a genre with it's tone (talking about nu-metal). It was on so many recordings in the 90's and early 00's, but the SLO hardly made a splash... I find it more 80's sounding myself. I think It would have been a lot more popular if it had been released 5 years earlier.

 

[rstites]

All that said, the recto practically defined a genre with it's tone (talking about nu-metal). It was on so many recordings in the 90's and early 00's, but the SLO hardly made a splash... I find it more 80's sounding myself. I think It would have been a lot more popular if it had been released 5 years earlier.

Don't discount that Soldano was always a small two-man shop with a limited distribution network and very pricey. While certainly not inexpensive, Recto's were far more affordable and far more readily found as Mesa had an existing distribution network throughout the country with a couple of decades behind it. What gets used is as much about business models as it is the specific sounds we get out of them. Much of our preferences for that sound comes later because we've already trained ourselves on what was there at the time. (This is true of Fender and Marshall too, of course.)

If the Soldano had been released 5 years earlier, it wouldn't have changed that much if most musicians couldn't find it and couldn't afford it....especially the pre-internet days.

 

[anomaly]

Don't discount that Soldano was always a small two-man shop with a limited distribution network and very pricey. While certainly not inexpensive, Recto's were far more affordable and far more readily found as Mesa had an existing distribution network throughout the country with a couple of decades behind it. What gets used is as much about business models as it is the specific sounds we get out of them. Much of our preferences for that sound comes later because we've already trained ourselves on what was there at the time. (This is true of Fender and Marshall too, of course.)

If the Soldano had been released 5 years earlier, it wouldn't have changed that much if most musicians couldn't find it and couldn't afford it....especially the pre-internet days.

I'm talking major lable bands though. They generally have access to all of the best gear in the studio. Price is rarely an issue when recording in a big studio. I'm sure many of those studios had SLO 100's.

 

[SonVolt]

SLO to me represents the worst of Van Halen & Clapton. I still don't get why they are, allegedly, iconic.

 

[rstites]

I'm talking major lable bands though. They generally have access to all of the best gear in the studio. Price is rarely an issue when recording in a big studio. I'm sure many of those studios had SLO 100's.

Most major label bands never get to the point of unlimited time in the studio with unlimited access to equipment, and all of that is an advance the band owes the label. People tend to use the gear they came up with on the first couple of major label albums, which is about as far as the vast majority of bands get.

However, it's a fair point that a lot bands who do get to that point choose some really weird oddball equipment or get a chance to use those one-off holy grail amps/guitars just for recording before hauling standard gear back out to tour.

 

[LPMojoGL]

Never played an slo but I'm getting great results tweaking the recto.
View attachment 442273

Recto is a blast!