SL-X 50watt gain question (and some)

[theflyingmat]

Hi guys,

I have a SL-X head. I really like the two channel function for solos etc. However, I do find it quite 'gainy' for my needs. By that I mean it sound more metal and rock to my ears.
My question is would be to do a mod that would make it more rock than metal? I'm not saying the sound is bad or anything, but I would just like a more rock like tone.

Oh and why does it sound better though the 900 cab, than my old greenback cab?

And while I'm at it, why does my DSL sound better through the GB cab than it does through the 900 cab?

cheers
B

 

[krish]

A good way to reduce the level of gain in an amp without compromising it's tone would be to replace the 12AX7 in V1 with a 12AT7. This way you'll find that cranking the gain doesn't make the amp as "gainy" but will give you the other benefits of really working the preamp tubes. Hopefully this will give the amp a bit more of a rock feel than metal.

I tried this in my DSL to try and tame the red channel with great results, but I went back to original configuration as it suited my band a little better. If I only ever used it at home it would still have the 12AT7 in V1.

Also, placing a balanced 12AT7 in the Phase inverter position (V4 in an SL-X I think) can help you push up the master volume control a bit more to help get rid of pre-amp fizz without blowing your head off. This is something I did with my Vox AC50CPH and it was definitely worth it.

I'm by no means an expert on how valves affect sound but I'm just speaking from my experience, so some of this may be slightly misinformed.


I don't have an answer about the speaker cab question. Different amps just suit different speakers better I suppose. I know my DSL loves Vintage 30s and Greenbacks, but just sounds like stiff fizzy wank through G12T-75s (in my opinion).

Not meaning to thread jack... but I've been interested in trying to get a 50 watt SL-X, how do you rate yours? How does it compare to the DSL?

 

[theflyingmat]

Thanks for the valve idea.

Regarding the SL-X and DSL. I really like the two channel thing with the SL-X. I think the DSL is a little more versitile and I really like the clean/crunch channel. However, I think the SL-X does the high gain dirty thing better. It'snot that I thought the SL-X was a poor sounding amp, I just would like a little more of a rock sound from it. Both good sounding amps though..
cheers
B

 

[Ken]

Using the guitar volume to take the edge off a high gain channel really works well. It will clean up your chords yet still have some menace. Then you can go to 10 for solos. Marshall tube amps respond really well to that, unlike Fenders (and my Music Man) that sound flat to me with the guitar on anything but 10.

Ken

 

[AxlOz]

Greetings from Oz. I also own a 50w jcm900 sl/x, and think theyre a great amp! I A/B'd it with one of the early jcm900 master volume heads and chose this one. It just sounded warmer and had more gain at its disposal.
Anyway, as for getting a more rock tone out of it, try setting your dials like this:

Pres 4, Bass 5, Mid 6, Treb 5, Master volumes [where you like], sensitivity 11-12, preamp gain 8-9.

In other words, I run the EQ with slightly enhanced mids, keeping treble in the mix, then I crank up the preamp but keep the sensitivity (the one that goes between 11 and 20) really low. This keeps some the tone nice and warm but stops it from being overly gain heavy.

I find these amps to be really quite versatile in gain settings, and contrary to what you might hear on the interwebs, clean tones CAN be had from them, just dont expect sparkly fender cleans. I usually play a les paul too so it breaks up a little easier.

I've been thinking about swapping some 12ax7's for some lower gain tubes just to satisfy curiosity but havent got round to it yet.. Could also be a good solution for you.

 

[Roadburn]

I never have the gain/sensitivity past 3-4.
Would changing pre-amp tubes give you more room in lower sensitivity settings. (as in you could dial in more precise/evenly???)

Right now it has:
4x EL34
1x 12ax7WB
2x 12ax7WA

 

[plankbadger]

Oh and why does it sound better though the 900 cab, than my old greenback cab?

Hi,
Are these cabs both 1960 cabs? You've got presumably G12-75 in the 900 cab and G12M greenbacks in the other?

I'm surprised. I've got an SL-X 50 head and a 900 cab (G12-75) and was thinking of changing the speakers to something else possibly greenbacks.

 

[AxlOz]

I never have the gain/sensitivity past 3-4.
Would changing pre-amp tubes give you more room in lower sensitivity settings. (as in you could dial in more precise/evenly???)

Right now it has:
4x EL34
1x 12ax7WB
2x 12ax7WA

shouldnt there be a 4th 12ax7...?


I'm curious to know which of the 4 12ax7's in the sl-x would have the most impact on tone if it were to be swapped for a lower gain tube. anyone shed any light on this?

 

[Roadburn]

shouldnt there be a 4th 12ax7...?


I'm curious to know which of the 4 12ax7's in the sl-x would have the most impact on tone if it were to be swapped for a lower gain tube. anyone shed any light on this?

Sorry, but I don't have an SL-X. Mine is a Mk III.

 

[theflyingmat]

Hi,
Are these cabs both 1960 cabs? You've got presumably G12-75 in the 900 cab and G12M greenbacks in the other?

I'm surprised. I've got an SL-X 50 head and a 900 cab (G12-75) and was thinking of changing the speakers to something else possibly greenbacks.

Yes both are 1960 cabs. I defo think the SL-X sounds better through the 900cab than the green back loaded one. Same with the DSL. I think it sound better through the GB cab than the 900 cab. this was even commented upon by the band singer...

 

[theflyingmat]

I don't have the gain that high to be honest. I'm not at home at the minute so I can't quote settings etc. I will try those suggested though. Maybe I should try to get as clean a sound as possible and use a pedal to get the gain level I require. It's just the whole 'sound' that the SL-X has got. I know I might get ribbed for this, but it sounds more heavy metal.

 

[AxlOz]

I run mine through a marshall 1936 2x12. used to have the G12T75's in it but i swapped them out for vintage 30s just to see how it'd sound. To be honest the difference is fairly small between the two.. Never tried it through greenbacks though.

I really doubt you'll need to run a distortion pedal through the SL-X.. Its got heaps of gain available, just so long as you like it a bit juicy. I wouldnt call it a metal amp specifically, but its definately got some hairy rock tones! I play mainly blues influenced rock stuff so i like to clean it up a little, which as mentioned above seems to be sweet with the sensitivity knocked back to 11 or 12, maybe a tad higher if i'm needing more thickenss and sustain. Metal amps need a much flatter response than these offer i think. I guess i'd describe the SL-X distortion as highly coloured, saturated tone, whereas the MK3's and the like are more an aggressive rock type distortion, with emphasis on high mids and highs for cutting solos etc. SL-X models can deliver this with the sens turned down, but they seems a little more creamy overall, which makes sense when you think about the extra tube saturating the tone..

As someone mentioned earlier, theyre also nicely sensitive to guitar volume settings, so be sure to play with that a little, it should take out some of the gain primarily.

 

[WrenchDevil6]

Volume knob.

 

[core]

shouldnt there be a 4th 12ax7...?


I'm curious to know which of the 4 12ax7's in the sl-x would have the most impact on tone if it were to be swapped for a lower gain tube. anyone shed any light on this?

V1 is going to effect your tone the most. Check out the last page of the Preamp Tube thread. I think someone else posted some questions about this amp in there and Marty and Joey Voltage were kind enough to give specs on it.

 

[AxlOz]

excellent, cheers for that! Just to capitulate on what was said in the other thread:

You see a 12AX7 is two circuits inside the tube. They can do two jobs. The circuits are called Triode A and Triode B.

Basically, it is like this:

V1A-Primary Gain Stage
V1B-Cathode Follower to Gain Pot (1-10) to V2A Grid (Ties into V2A)
V2A-Gain Stage to Gain Pot (10-20)
V2B-Gain Stage
V3A -Gain Stage
V3B - Cathode Follower to Tone Stack to Op Amp Buffer.
V4AB-Phase Inverter (Power Amp Section)

This amp lives up to its name with massive amounts of gain. V1A, V2A, V2B and V3A are your four stages of gain. I would go with a Tung-Sol in V1 and then a hand select high gain Mullard RI in V2 and another Tung-Sol in V3.

If you want to turn it into a crunch machine with a minimal clean, then go with two hand select high gain Mullard RI's in V2 and V3.

You don't need gold pins or a perfectly balanced Phase Inverter tube.

link to post here

 

[AxlOz]

oh and unless I'm mistaken, V1 is the tube on the left hand side when looking at the back of the amp. V4 is the tube closest to the power tubes.

 

[Toogy]

So to my understanding changing the V4 pre-amp tube would have very little impact on the tone of the amp?

 

[AxlOz]

from my understanding the PI tube wont really affect the tone much at all. If you happen to have a tube in there that has vastly different triodes then it may make things sound a little different to a tube with matched triodes though. The matched one will sound a little smoother. Probably barely noticable though..

I put a NOS 12AT7 in my PI slot of my 2500 and it does sound a little smoother, but certainly not as big a difference as swapping out v1 or v2..

 

[dixie duncan]

I have a SL-X head. I really like the two channel function for solos etc. However, I do find it quite 'gainy' for my needs. By that I mean it sound more metal and rock to my ears.
My question is would be to do a mod that would make it more rock than metal? I'm not saying the sound is bad or anything, but I would just like a more rock like tone.

B

I'm VERY interested in what you learn with this, as I am in the same boat. I'm using all single coil teles and strats, but they're hotter than stock. I'm playing rock n roll, like classic rock, but with a more attitude. I look forward to hearing more about it.

 

[MartyStrat54]

I never recommend a 12AT7 as a V1 tube. They just don't sound that good. I say you can always get it done with the right 12AX7. I will say that there are some other options out there to tweak your tone, but if you want to go with tubes, then I say for the OP situation, go with a lower gain 12AX7 in V1 and a slightly hotter one in V2.