Comparing the Two SLASH Marshall Mods! S.I.R #34 vs #39

[@frishdaw]

#34 has THAT sound! The natural compression, sounds excellent!

[@JohanSegeborn]

Thanks!

[@extramile734]

Johan Segeborn, I admire and respect your work and contribution to Rock knowledge.

[@JohanSegeborn]

Thanks, makes my day to hear that!

[@auruxy]

I always love how the sheer volume shakes the cameras, great video as always

[@JohanSegeborn]

Thanks Luis!

[@Ontariosound]

A touch of channel strip EQ, boosting by 3 - 6 db at 10K could match the 34 to the 39. EVH said a few times that the console EQ during Mixing was part of his sound.

[@corneliuscrewe677]

Man those both sound amazing. Two different flavors of THE sound. Of course, trouble is Johan could make a Gorilla 10 watt amp sound amazing.

[@joecooper7803]

Then the price would go up

[@corneliuscrewe677]

@@joecooper7803 Probably already has 😆

[@JohanSegeborn]

Thanks my friend, that’s too kind ;-)

[@andreacampana4754]

They both sound incredible. The 36 has that GNR taste, the 34 just roars and is my favorite! Great video!

[@JohanSegeborn]

Thanks Andrea!

[@AnodyneHipsterInfluencer]

I think each one excels at what the other doesn't and would sound incredible together. 34 would bring the body and grunt and 39 would bring the sizzle and sustain.

[@JohanSegeborn]

Thanks! I agree

[@qua7771]

So a SIR #73?

[@jcoulter43]

Anything with Forsberg attached is incredible! I love the sound of both these amps. 34 is a little darker and 39 has got that sizzle. Perfect way to end the week on black Friday! God bless and Forsberg on 👍😎🎸

[@JohanSegeborn]

Yeah Forsberg is a tone magician. Have a great weekend!

[@danielforsberg4018]

Thanks Guys! 😊🙏❤️🙏

[@plexidust5101]

Sounds Fantastic ! #39 was used by George Lynch on Tour In Support of " Under Lock & Key ". He used a Super Distortion and likely G-12-75 T . Perhaps he used less gain and could have been slightly smoother with less edge. Its got the tone though. #34 is Glorious also, Its a coin toss !

[@JohanSegeborn]

Thanks!

[@budgetguitarist]

Both sound amazing! I think I like #34 better, but they're really both stellar.

[@JohanSegeborn]

Thanks, glad to hear it!

[@eddieholmes3236]

#34 was spot on. Lots of grunt from the BB3. Thanks Johan!

[@JohanSegeborn]

Thanks Eddie!

[@8bigtubes]

That SIR #39 is THE AFD sound! The cut, the high mid push, the tight low-end......DAMN!

[@plotonisradd]

man , Johan never disappoints does he ? You rock sir !

[@JohanSegeborn]

Thanks! Glad you like it!

[@plotonisradd]

@@JohanSegeborn like it ? no sir no , i L-O-V-E your work

[@jayguitar]

Really awesome hearing those two circuits side by side. I have both courts built into my custom Purple#39 amp and they have that same vibe. Somebody mentioned he brightness’s do slight oscillation on the #39 and that’s happens with mine too. So much gain with 39 as well. Q for you Johan, have you tried or experimented with the Aspen Pitman Purple Plexi Marshall circuit? That one was also extensively used by George Lynch and is pretty amazing as well - built into my amp also (different negative feedback and presence). Warmer then the #39. Have a great day.

[@mikkywhalan]

34. Warmer but still loads of clarity

[@deadsoundradio]

Surprised that I preferred the #34, but both record beautifully 👌🏾 Cheers Johan!

[@JohanSegeborn]

Glad to hear it! Cheers

[@Twobarpsi]

Oh man that opening jam on that 39 is pure gold 🍺🤘🤘🤘!!

[@JohanSegeborn]

Thanks, really good to hear that!

[@WillelmMacguyver]

Hey Johan, I mean no disrespect to your playing or recording here, which was good as always, but I've built and experimented with these SIR circuits fairly extensively and both of these amps sound really off, particularly the "SIR #39". These circuits are supposed to be bright but not like this, more of a 'sizzle' than this grating top-end that literally hurts my ears to listen to. If I had to guess why it sounds so harsh, I'd start by checking to see if the input cable is 'hot shielded' or at the least if there's a small (typically ceramic, 10-100pF) plate to cathode capacitor to simulate it's effect; I have also seen in some later Caswell mods that the shielded cable coming off the first gain pot to the second (overdrive) gain stage would also be hot-shielded in addition to the input stage. It should also be noted this is a feature common to both the 4 stage #36/#39 and the 3 stage #34. Also check the "#39" to see if the R/C divider after the 3ird overdrive gain stage is 470k//470pF(series) and ~250k(shunt) and not 470k//470pF and 470k. This is a very common error in many of the schematics out there but every Caswell I've ever seen had a R value in the 200k range, either 240k or 270k. This circuit with both cathode cap switches engaged is just barely stable so the difference between 470k and 240k here matters alot.

[@danielforsberg4018]

Hi Willhelm! I understand what you mean. I omitted the hot shielding in one place of every amp for one big reason: Because it really depends on the length of the cable and it takes away the fizz in an unnatural way and sounds dull. So 20cm cable sound different (different capacitance) than a cable 40cm long. Connecting the shield to ground, or to the cathode, doesn’t have that effect.

[@07parachute]

Loved them both. Combo sounded slightly compressed, in a good way, and the head sounded more open which i loved as well. But I definitely enjoy the sound of the SG. İt sounds great.

[@JohanSegeborn]

Thanks Emre! Yeah the SG has become my go to guitar!

[@ericschrdr]

Always great reviews! With so much access to awesome gear, I wonder if you've considered creating or have created impulse responses for some of the cabinets. I typically don't like amp modelers but have been playing around with a helix and I'm impressed with the impulse response capabilities - it doesn't compare to the real thing imo, but it's come a long way.

[@chrisrobinson6754]

I have a #34 Levi Superkill mod done on my 1980 JMP 2203 by Jay Linton in Utah, I can get just about any GnR Album tone on it just depending on the settings, works for my ears at least! Running JJs in all three Pre's and Tung Sol 6550 Coke Bottles for Power biased at 40mA. I have an extra Master so I can crank the Power more for UYI Tone.

[@truereligion7752]

Wow wow both are tonecrazy Love them Mr Forsberg is a gain ruler

[@DANTHETUBEMAN]

Your in good company I see. All great rock amps.

[@JohanSegeborn]

Thanks Dan! :-)

[@astro2069]

Johan, did you ever try out the sir #34 with the legendary tones hot mod? Real curious about that combination. Thanks for everything!

[@IGarrettI]

I hear the appetite hint in the 34 but not the tone. I think a Les Paul, SD and adjusted settings would do it. Both mods are incredible!

[@rocketpigrecords3719]

34 is Illusions, 39/36 are Appetite

[@d-sidespazuzu8971]

I really enjoy your videos

[@orbitaljellyfish808]

Would love to see a repeat of this with a Les Paul (SD pups, orange drops etc) and also throw in that Pedal PAL 800 v3 that has the AFD switch 👏👏

[@Kyush4]

Great work as always, would had love to hear the 6:43 riff through the 34, I assume the 39 would be better for early Metallica tones?

[@stevencancel1727]

Those G12 H 80 with 444 cone original 1979 really work well with the 50 watt late 70's JMP heads, sealed cab only of course!

[@JohanSegeborn]

I actually replaced the G12-80 with V30 here, but G12-80 is what Slash most likely used on AFD

[@jacekfeliks4730]

I saw that room GNR were recording in S.I.R, NYC. It was more a theater like stage, not a typical studio. I guess that's where the reverb is coming from...

[@jamescarpenter4777]

SIR was in L.A. thats where they recorded

[@infectionsman]

Johan, there is a whining noise in the background of your recordings. I think it could be a ground loop causing high frequency noise. I suffered the same kind of noise and I had to remove some of my devices from the signal chain and also run the laptop from battery to get rid of the noise when recording. Maybe an isolation transformer on the signal between troublesome devices could help?

[@infectionsman]

Great sounds by the way, is this based on the amp Slash stole from the rental company?

[@JohanSegeborn]

Thanks, yeah the #39 is similar to the #36 that Slash stole

[@JohanSegeborn]

Yeah that 5kHz noice is killing me. It’s most likely related to parts of the building I have no access to. With Strat and long cables it’s just unbearable. I’m gonna solve it

[@oldebrodersen4661]

#39 killer tone! How can I change my 2003 into that?! Johann? Any explanations or even Layout shemes?

[@BMichel347]

Both were good, love the 34.

[@MrSheymie]

Both sound tremendous. I think I prefer #34. Slightly more grind and very characterful tone. #39 is probably best for lead playing and if two guitar players are playing together. Come to think of it, #34 for rhythm and #39 lead would probably make a very nice combination.

[@verruckterwissenschaftler]

Very Sweet

[@JohanSegeborn]

Thanks!

[@davidstephens1097]

Great demo Johan! I can’t decide which one I like better. Do you think someone could get similar results with a non hot modded Marshall and a good treble booster? In the video, my ears hear what a treble booster might do.

[@JohanSegeborn]

Thanks David! A treble booster pushing a Super lead wouldn’t sound as firm for palm mutes but would get pretty close for some playing.

[@davidstephens1097]

@@JohanSegeborn thanks Johan! 😊

[@ruggie.74]

I'm pretty sure Slash used v30s ALWAYS. Am I wrong? I don't ever remember him recording AFD or UYI with Greenbacks and what not.

[@jamescarpenter4777]

He used g12-80 on afd and 25 watt greenbacks on uyi.

[@donsmith5385]

You got to try a Randall BMF if you like that tone, imho I feel the BMF is better, the power section is massive in comparison

[@jamescarpenter4777]

Don Smith i have a BMF! its one of the prototype models without the vents on top. It is a killer amp!

[@donsmith5385]

@@jamescarpenter4777 the creator of the amp is Kevin Nelson, he is an amp wizard! He made some ground breaking amps! He created the Music Man Amps when Leo Fender owned Music Man

[@jamescarpenter4777]

@@donsmith5385 yes he did. My bmf has been serviced by him

[@qua7771]

I had a similar mod on a clone. There were treble peakers on each glain stage that sounded harsh to my ears, and the highs fed back liked crazy. Despite what I liked about it, I had to tame the circuit back a little.

[@rickya3877]

34 has more natural power tube grunt while 39 has more preamp gain...both sound great 🎸🎵💥🍻

[@Burkhimself]

So I assume the #34 has a diode adding some gain if there’s not an extra tube ? I was kinda turned off by the whistling feedback. I think I prefer the head (39/36)….which one cleaned up best with the guitar volume ? ….killer vid as always !

[@JohanSegeborn]

Thanks! None of them cleans up well actuslly

[@jamescarpenter4777]

None of these mods have diodes

[@eyedunno8462]

It's adding a cathode boost cap to the 10k cold clipper, rasing the first peaker cap to generate more gain, more high and mid cut from the stock circuit which pushes it to the very edge of its' limitations. Then, subsequent snubber caps, high cuts to tame the extreme high end content to get those delicious mids coming through. More than that, you really need to add an extra tube. The 34 is useful in that you don't have to.

[@zombiemosher1139]

Both sound killer man but the #39 is where its at for me.

[@hootowl6354]

What about #69? Can we see a demonstration of that one?

[@danielemella1758]

Fantastico rock'n'roll Sound 😈❤😇!Grande

[@DMSProduktions]

WOULDN'T kick either out of bed! \m/

[@JohanSegeborn]

Cheers DMS

[@louaguado995]

#34 for the win! Much smoother treble response. The super bass was too harsh sounding. I wish you would have used different levels on your guitars volume control instead of always on 10

[@skylarcarlson7745]

I have that same shure 548. How do you like that mic? I’ve had it for 20 years or so and don’t use it much. Wonder what that thing is worth right now?

[@JohanSegeborn]

It’s my go to dynamic mic. They’re pretty rare actually. Cheers

[@OgamiItto70]

Liked 'em both. Liked #34 better, though. #39 was gettin' a little shrill and had more distortion. Maybe too much. Save some for my dirt pedals, dude! Of course, swap out for a different cab/speakers and maybe the whole picture changes.

[@Burkhimself]

Which did you prefer more Johan ? Did one of them “scratch that itch” more than the other ?

[@JohanSegeborn]

Hi I preferred the 39 when I played. But recorded the 34 sounds better for sone of the riffs on

[@MrHerb664]

I had always thought the 39# was made famous by George lynch , and the 36 was more jubilee structure I thought 🤔? And the 34# is totally guns and roses even in this video. 39# has lynch drive tonality to me but just my thoughts

[@ein1002]

I like #34

[@JohanSegeborn]

Thanks!

[@djent1448]

I like the #39 way better, sounds way more natural to my ears. The #34 sounds too compressed and too middy/nazaly for my taste.

[@JohanSegeborn]

Thanks

[@djent1448]

@@JohanSegeborn Cheers! Wich one did you prefer Johan?

[@EJH-jn6mo]

Would love to hear how 39 compares to a Bogner Ecstasy 101B

[@JohanSegeborn]

Great idea for a video

[@gil_evans]

I hear a soft whisteling on the #39. Is that a slight oscillation?

[@semdallinga69]

I’m not sure but if that’s the case it’ll be expensive to keep replacing tubes

[@masecardrums]

Yeah, unfortunately it seems to appear in most of Johan's videos these days, at least those taken in this room. It's in the #34 too, it's just not as loud because it's not as bright.

[@semdallinga69]

@@masecardrums perhaps the guitar picks up some high frequencies from all the equipment in the room

[@masecardrums]

@@semdallinga69 I believe it to be related to power or lights.

[@liverpoolred2834]

Want both :-))))))

[@GTguitarworks]

I don’t think the #39 sounds good on the top end, I am currently in the middle of modding a 2204 with a extra 12AX7 gain stage & wasn’t even going for the number 39 sound really, and I think my modded 2204 sounds a lot more like a #39 than that #39 does. I’m just guessing here but it sounds like he’s got large plate snubbers on the first gain stages which will cut some treble but boost the very top /presence frequencies, giving it a lot of fizzy top upper high end when you already have that extra gain stage pushing more frequencies, you don’t need plate snubbers. You need attenuating resistor on the high pass capacitor and then you’ll have that tight top end you hear on the album. In my opinion after doing these mods myself I don’t think the schematic you find online sounds like the number #39 on the album. I think if you go with the Niel special schematic/diagram you get a much closer sound because it’s just copying the original second gain stage with a 10k cold clipper, in the added gain stage. With a 1 Meg to ground off the coupling cap and 470K voltage dividers/attenuators. Then wire it all straight into the original third gain stage 470K attenuator/voltage dividers. To me it sounds a lot more like slashes sound on the album.. but again this is just my opinion.

[@charlesbukowski9836]

34 wins hands down.. same great punch and drive but warmer

[@astro2069]

Which do you prefer, 34 or 39?

[@IAMTHERAZOR]

Any links to schematics? TIA

[@gitarbangsatchanel8036]

Killer

[@Guitarista78]

I'd prefer 34 in a live setting, 39 in a recording...

[@EB1775]

#34 f’ing rips

[@MrJamescord]

Like the 34 much better

[@jaricklosey4607]

39 sounds more like AFD and 34 sounds more like UYI

[@stoofystoof]

My #34 is not as gainy as yours

[@HiHello-ku1fl]

Prefer #34.

[@aferreyrola]

i liked 34 better.

[@curtisprice9806]

#34 HAS GIRTH, GRIT...NOT TINNY/ THIN( MY FIRST IMPRESSIONS )