New MT15 has 6l6?? & cab question

Dreaming90s

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Stopped playing 25 years ago, sold everything. I had a mesa 95 dual recto with the 4x12v30 cab. Played Les Paul’s. Heavy rock (aic, early foo’s, soundgarden).. so metal tones did work at times, lived on the vintage bit modern channel, just slight gain adjustments…


Here we are 25 years later, I just bought a new (used 2024) Les Paul studio… the MT15 was on my radar but I gave a marshal dsl20hr with the marshal sv2x12v type vert cab a try due to the mt15 moving on from 6l6’s, anyways the Marshall - Trashy ice pick high end with any good amount of gain. Terrible boxy low end. So I just flipped that rig with out losing money. I was never a Marshall fan.

I’m just playing in my home office, will never gig or record again.. the mt15 was on my radar until I read they did away with the 6l6s…

Yesterday I noticed a post on Facebook MP someone in my area (very tiny music store that only has prs stuff, mainly do music lessons etc) selling a mt15 it said equipped with 6l6s… I assumed it was just a copy and paste of the original text adds…


So I stopped and sure enough it had 6l6s! It has a white sticker that says 1/24 (I assume that’s the build date)

Question 1 - I thought they stopped using 6l6s? These were like 6l6 gcc maybe or something?

Question 2 - I first played it through what they thought was the matching cab (with my new lp) 1x12 model number - sk112-cv3_bl sounded meh… ice pick high end like the Marshall but a tighter low, reminded me of the of Marshall a bit… so they had a PRS 2x12, I’m like let’s try this. Model number sk212-cvt_st this cab broight the amp to life! Tight bottom, no ice picks in my ears with the volume up on high gain, no sizzle playing the amp high, no gain fizzle at low volume. Anyone have experience with this 2x12? The guy that owns the store told me both cabs had v30s. That 2x12 definitely didn’t, it had something much smoother and ear pleasing. Google isn’t giving me much info. Seems the 1x12 may have been a v30 and the 2x12 might be 70 watt “v type”…. The Marshall cab I have is “v type” and ice picks my ears… thoughts on this 2x12?

I can get the 2x12 (retails around $500?) and the head (retails for $799) for $1050 they are both nee. He knocked $50 off the head because it’s a floor model (every amp I ever bought back in the day was a floor model lol) and he knocked $200 off the cab. I’m gonna go for it. Liked the tone. It was closer to my old dual recto then anything small I’ve heard or tried. It sounded better than the mini recto.


Thanks for your help!
 
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Stopped playing 25 years ago, sold everything. I had a mesa 95 dual recto with the 4x12v30 cab. Played Les Paul’s. Heavy rock (aic, early foo’s, soundgarden).. so metal tones did work at times, lived on the vintage bit modern channel, just slight gain adjustments…


Here we are 25 years later, I just bought a new (used 2024) Les Paul studio… the MT15 was on my radar but I gave a marshal dsl20 with the marshal sv2x12v type vert cab a try. Trashy ice pick high end with any good amount of gain. Terrible boxy low end. So I just flipped that rig with out losing money.

I’m just playing in my home office, will never go for record again.. the mt15 was on my radar until I read they did away with the 6l6s… (I tried the marshal because it had el34’s)…

Yesterday I noticed a post on Facebook MP someone in my area (very tiny music store that only has prs stuff, mainly do music lessons etc) selling a mt15 it said equipped with 6l6s… I assumed it was just a copy and paste of the original text adds…


So I stopped and sure enough it had 6l6s! It has a white sticker that says 1/24 (I assume that’s the build date)

Question 1 - I thought they stopped using 6l6s?

Question 2 - I first played it through what they thought was the matching cab (with my new lp) 1x12 model number - sk112-cv3_bl sounded meh… ice pick high end like the Marshall but a tighter model… so they had a PRS 2x12, I’m like let’s try this. Model number sk212-cvt_st this cab broight the amp to life! Tight bottom, no ice picks in my ears with the volume up on high gain, no sizzle playing the anp high on low volume. Any have experience with this 2x12? The guy that owns the store told me both cabs had v30s. That 2x12 definitely didn’t, it had something much smoother and ear pleasing. Google isn’t giving me much info. Seems the 1x12 may have been a v30 and the 2x12 might be 70 watt “v type”…. The Marshall can I have is “v type” and ice picks my ears… thoughts on this 2x12?

I can get the 2x12 (retails around $500?) and the head (retails for $799) for $1050. He knocked $50 off the head because it’s a floor model (every amp I ever bought back in the day was a floor model lol) and he knocked $200 off the cab. I’m gonna go for it. Liked the tone. It was closer to my old dual recto then anything small I’ve heard. It sounded better than the mini recto.


Thanks for your help!
Sweet! Congrats on the find, and welcome to the forum.
 
If you seek that the MT15 sounds like PRS wants the MT15 to sound, then you need to acquire the suited cab.

If you want to make the MT15 to be your amp for your sound, then consider a neural speaker, to allow the amp to breath without colouration by a given speaker.

I did that with my BluGuitar Amp 1 (Iridium Edition). Though the founder was more than two decades sound designer of Hughes & Kettner, he is absolutely Marshall impressed.
First of all I learned about three dimensional soundings cabs by UK based company Barefaced. At that time their speaker selection was Celestion only. Me was recommended to take the V30. But I went own ways. Comparing all descriptions about each driver of Celestion in 2020, I pointed the 12" Celestion Neo 250 Copperback. He was described being a non-colouring. Additional pluses: A lot of reserve for power handling, low/insensitive for break up, the louder it gets, lightweight. The whole cab is 7 kg.
Later I took without any moment of hesitation the Neo for a 2×12 sized custom made cab (aswell three dimensional emitting). The other speaker in crime became the EVM-10M, 10" indeed.
 
Thanks for the replies. Picked the head up yesterday. I went with the 2x12 stealth cab with the vtype. I didn’t want a 1x12 so that was part of the reason, other, these New Les Paul’s with burstbucker pros are so damn bright. They don’t work well with v30s imo when using any kind of moderate to high gain. You have to dial out all the treble. I’ll prob swap the bridge out for the good ol 498t. So far so good, only played around for about an hr yesterday after bringing it home. Currently with the mt15 I’m running gain and Trevor around noon. That Marshall dsl20
I literally had to have to treble off. I was never a marshal guy, not sure why I even tried that thing.
 
Really enjoying this amp. Coming from a 95 mess dual recto back in the day, this head sounds more like my old dual then the mini dual they make lol… the stealth 2x12 cab with vyoe isn’t bad at all, Espically for the price I got it at new ($300)… very pleased for the application of just playing at home….
 
In modern parlance, the 6L6 GC is what most people (and typical amp specs) are referring to when they talk about a 6L6.

I think the MT15s at some point came with 5881s, which are a 6L6 variant, and are interchangeable with the 6L6 WGB, the 'W' being a military tube designation; the tubes also may have been available as 6L6GB, but I've only seen NOS ones with the 'W'. The 5881 breaks up a little earlier than the 6L6 GC.

As far as I know, the true 6L6 (they started making them in the 1930s) can't handle the plate voltages of the 6L6 GC, which is why amp makers use the GC tubes now.
 
In modern parlance, the 6L6 GC is what most people (and typical amp specs) are referring to when they talk about a 6L6.

I think the MT15s at some point came with 5881s, which are a 6L6 variant, and are interchangeable with the 6L6 WGB, the 'W' being a military tube designation; the tubes also may have been available as 6L6GB, but I've only seen NOS ones with the 'W'. The 5881 breaks up a little earlier than the 6L6 GC.

As far as I know, the true 6L6 (they started making them in the 1930s) can't handle the plate voltages of the 6L6 GC, which is why amp makers use the GC tubes now.
Yes, I was under the impression they were using strictly 5881’s for the past few years due to a factory that burned down, I was kinda shocked to see a brand new mt15 with 6l6gc. Date on the sticker is 1/24, so it sat for a year in this music store.
 
In modern parlance, the 6L6 GC is what most people (and typical amp specs) are referring to when they talk about a 6L6.

I think the MT15s at some point came with 5881s, which are a 6L6 variant, and are interchangeable with the 6L6 WGB, the 'W' being a military tube designation; the tubes also may have been available as 6L6GB, but I've only seen NOS ones with the 'W'. The 5881 breaks up a little earlier than the 6L6 GC.

As far as I know, the true 6L6 (they started making them in the 1930s) can't handle the plate voltages of the 6L6 GC, which is why amp makers use the GC tubes now.
This is pretty much how it is.

The 6L6GBs pre-dated the WGBs, and aren't capable of handling the same plate voltages. The WGBs, which were Joint Army Navy specified (hence JAN) from Philips, were very much closer to GC specs in terms of what they could dish out. They'd been "rugged-ized" for military 5881 applications, and I've run sets of these for years in amps that would also be fine with GCs.


I'd say the TAD-labeled WGCs that came from China - until their factory burned down (or whatever it was that really happened) - were some of the most musical tubes made since Philips and Sylvania stopped manufacturing their 6L6s. I've still got a few sets, along with some of the newest TADs. I'll be able to give an opinion on these soon(ish), as I've just fried a "5881" in one of my Tone-Masters........ :rolleyes:


I do play quite loud at times :)
 
Yes, I was under the impression they were using strictly 5881’s for the past few years due to a factory that burned down, I was kinda shocked to see a brand new mt15 with 6l6gc. Date on the sticker is 1/24, so it sat for a year in this music store.
If you'd rather run a set of the best sounding 5881 types s they can be found NOS - get the Philips 6L6WGB, as Runcible says, or better still, the Tung-Sol NOS.

I used these instead of 6L6s in Two-Rock Onyx and Artist models (in fact, they were installed by Two-Rock during manufacture at my request), and they sound absolutely great.

They will break up a little earlier than the 6L6GC - assuming that you run your amp at full throttle, Master Volume wide open letting the power tubes distort, not just the preamp tubes.

Most people don't play loud enough to drive their output tubes hard enough to really break them up. For my studio work, I often have.

The drawback is that a set of Philips NOS will set you back about $150, the Tung-Sol NOS about $300.

Might as well install a set of NOS 12AX7s if you're going that route, and get really spendy - there is a difference, but you'll be out some dough. I think it's worth it in my amps, but I don't run anything made in China like the MT-15, and spent enough that the investment made more sense to me.
 
If you'd rather run a set of the best sounding 5881 types s they can be found NOS - get the Philips 6L6WGB, as Runcible says, or better still, the Tung-Sol NOS.

I used these instead of 6L6s in Two-Rock Onyx and Artist models (in fact, they were installed by Two-Rock during manufacture at my request), and they sound absolutely great.

They will break up a little earlier than the 6L6GC - assuming that you run your amp at full throttle, Master Volume wide open letting the power tubes distort, not just the preamp tubes.

Most people don't play loud enough to drive their output tubes hard enough to really break them up. For my studio work, I often have.

The drawback is that a set of Philips NOS will set you back about $150, the Tung-Sol NOS about $300.

Might as well install a set of NOS 12AX7s if you're going that route, and get really spendy - there is a difference, but you'll be out some dough. I think it's worth it in my amps, but I don't run anything made in China like the MT-15, and spent enough that the investment made more sense to me.
My stage and studio days are long gone. I’m just playing by myself, to myself 20 years later…
 
If you'd rather run a set of the best sounding 5881 types s they can be found NOS - get the Philips 6L6WGB, as Runcible says, or better still, the Tung-Sol NOS.

I used these instead of 6L6s in Two-Rock Onyx and Artist models (in fact, they were installed by Two-Rock during manufacture at my request), and they sound absolutely great.

They will break up a little earlier than the 6L6GC - assuming that you run your amp at full throttle, Master Volume wide open letting the power tubes distort, not just the preamp tubes.

Most people don't play loud enough to drive their output tubes hard enough to really break them up. For my studio work, I often have.

The drawback is that a set of Philips NOS will set you back about $150, the Tung-Sol NOS about $300.

Might as well install a set of NOS 12AX7s if you're going that route, and get really spendy - there is a difference, but you'll be out some dough. I think it's worth it in my amps, but I don't run anything made in China like the MT-15, and spent enough that the investment made more sense to me.

After reading your post, I went to my "spare tube" boxes and had a look at what I've got - EL34s, 6L6s, 5881s, 7581As, etc. A load of them are still un-matched, purchased over the last twenty+ years as pulls, NOS, ANOS and so on.

Quite a few small bottle "6L6 family" tubes in there, including GE, Tung-Sol, and Philips. I'll test a few of the non-Philips in case I can get a strong set together for the Tone-Master, and to see if they offer any musical advantage over the usual suspects.


I've got them, and should darned well use them, or they'll end up in land-fill along with me 😁
 
After reading your post, I went to my "spare tube" boxes and had a look at what I've got - EL34s, 6L6s, 5881s, 7581As, etc. A load of them are still un-matched, purchased over the last twenty+ years as pulls, NOS, ANOS and so on.

Quite a few small bottle "6L6 family" tubes in there, including GE, Tung-Sol, and Philips. I'll test a few of the non-Philips in case I can get a strong set together for the Tone-Master, and to see if they offer any musical advantage over the usual suspects.


I've got them, and should darned well use them, or they'll end up in land-fill along with me 😁
That makes total sense!

My tubes and I have the same landfill potential, so I've been installing what I have in my amps - gonna use 'em before I lose 'em (I have a few waiting just in case I somehow acquire another amp, which...I mean, ya never know). 🤣
 
During the pandemic, PRS, like just about everyone else, was pressed for getting tubes for their amp models so they had to switch to something else that was more obtainable. I believe the story was they tried the 5881's in an amp and Tremonti liked the sound of them and so that's what they went to. I have an original MT15 with the 6l6GC tubes and have paired it with both the matching 1x12 cab and my Mesa Recto 2x12. Both sound huge and the Mesa cab absolutely just punishingly awesome. One thing I would strongly suggest checking once you get your amp is the bias on the tubes. These amps seems to sound best on the hotter end of the spectrum. Try to get the bias as close to 30mV as you can. Mine initially came around the lower end of the spectrum about 27mV. When I set it at 30mV average between the two tubes it sounded even better.

Tubes I have used in this amp have been ruby, Mesa, and now JJ.
Ruby - these are the originals, sounded ok, not great not bad. Was looking for something less grainy.
Mesa - very smooth, but didn't last long and started making weird noises when warming the amp up.
JJ - best tubes I have put in this amp. Strong, responsive, very clear, not woofy in the bass, and quiet.

Enjoy the amp dude! It's Killer \m/
 
I have an early version of the MT15 with 6L6GC’s, and I picked up another to leave at a rehearsal space, and it has the 5881’s. Once they hit a track, I don’t hear much difference between them.

I do prefer swapping the V1 to a lower gain 12ax7, and the PI to a 12AT7, just to give more clarity… not that anyone asked!
 
I have an early version of the MT15 with 6L6GC’s, and I picked up another to leave at a rehearsal space, and it has the 5881’s. Once they hit a track, I don’t hear much difference between them.

I do prefer swapping the V1 to a lower gain 12ax7, and the PI to a 12AT7, just to give more clarity… not that anyone asked!
So after sometime, I can’t seem to get this gain where I want it… using les Paul’s (one with high output 498t the other with a 57plus… I’m going after 90’s gain (early foo’s, soundgarden and as heavy as AIC) I’m either getting to much gain or not enough.. I feel like I need to take this gain, or get something to make the gain more clear for note definition… I keep flipping between 11 o’clock and 1oclock… master volume is only 9 o’clock… I thought about a 12at7 in the second gain stage to hopefully “clean it” unlike the tone of the gain, jsut can’t dial it… I’ve read people using 5771? (Lower thwn a 12at7)bin the second gain lead channel postion… I don’t want it to sound like a Marshall, I used a dual recto rev g in the 90s… so the PI slot, I’ve read you shouldn’t play with it? The valvue is set for a certain tube?

I happen to have a new jj 12at7 here lol, try it in the PI first? Or better to try and bring the gain down?

Thanks!
 
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