# DIY 18 watt marshall kit or jtm45 kit from Mojotone



## copperhead (May 24, 2006)

I'm considering building one of the 2 ,Im leaning toward the 18 cause i don't really need a loud amp
I would not mind trying a Trinity kit, but i get dealer pricing from Mojotone, so i can save a bunch

so this is my first amp build but i seen a couple being built on YouTube & look pretty easy ...soldering is not a problem 

Question is has anyone built a Mojotone kit ? & how easy are there instructions to understand ?
also which amp to build ,18 or the jtm45
thanks


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## Guest (Sep 5, 2011)

Been wanting to build one of these kits for a long time. Just not sure which one to get that would be best for a novice. When I say novice I mean in terms of knowing a lot about electronics etc. Soldering would be OK. Having a detailed set of instructions would be best for me


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## hollowbody (Jan 15, 2008)

I have a JTM45 and I'd like to build/get an 18 watter, so I'll chime in on the choice part at least. I love my JTM45. I practice with it all the time and I gig it regularly and it always sounds fantastic, BUT (and it's a pretty big but) that sucker is LOUD!!!!! I'm running KT66s in it, so it tops out around 36 or 37 watts, and I definitely cannot run it where I like it without an attenuator. Running it lower than that, it's a great platform for pedals, but my Marshall-in-a-boxes aren't as good as my JTM45 wide open, so I prefer running the normal channel at around 6 or 7 on the volume dial and the treble channel around 8 or 9.

I get great 70's rock tones and turning the volume on the guitar just a bit gets me some less hairy 60's tones. Turn down a touch more and you get fantastic cleans.

So yeah, great amp. I'll always keep it, but I'd really rather have an 18 watter and not have to carry around an attenuator with me.


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## DavidP (Mar 7, 2006)

I'd go with the 18W in combo format with 2-12s (preferably a Hellatone and a Blue). I built one from a Trinity kit a few years ago now -- great amp for studio and gigging! FWIW I'd go with Trinity as his parts were top-rate and no customs hassles.


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## copperhead (May 24, 2006)

thanks i'm only building the head kit ,I will make my own head ,probably curly maple
& i'm leaning towards the 18 watt ,i don't need it to be any louder than my 15 watt amps i have now
Can the 18 watt do hard rock ?


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## copperhead (May 24, 2006)

Im leaning toward the Jtm45 with a Post Phase Inverter Master Volume 
to get the tone at lower volume 
how heavy can a jtm45 or the 18 watt do ....I do hear a bunch of youtube video ,doing vintage AC/DC with them

just a thaught if it will replace my tiny terror or maybe i should be looking for something like a jcm800 but low watt


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## keto (May 23, 2006)

Ya, you're not going to get anywhere remotely close to Tiny Terror gain levels with either of those amps, without a pedal. Think 60's-70's rock at best, on its own (more with pedals, obviously).


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## hollowbody (Jan 15, 2008)

copperhead said:


> Im leaning toward the Jtm45 with a Post Phase Inverter Master Volume
> to get the tone at lower volume
> how heavy can a jtm45 or the 18 watt do ....I do hear a bunch of youtube video ,doing vintage AC/DC with them
> 
> just a thaught if it will replace my tiny terror or maybe i should be looking for something like a jcm800 but low watt


My JTM45 gets pretty dirty, but it's not 80's metal kinda dirty, more like a really raunchy AC/DC or Black Crowes with high-output humbuckers. I have no problem covering some slightly heavier stuff like Pearl Jam or STP. But yeah, goosing it a bit with my Timmy or OCD gets me into hair metal pretty easy.


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## Emohawk (Feb 3, 2006)

You can do the cascade mod on the Trinity 18, or the "Rhoades mod" (similar concept) on a JTM45/Plexi to get more gain. If you built a Trinity 18w TMB (the highest gain version) with that mod it should be pretty close to early 80's heavy metal territory, possibly even in Tiny Terror territory (but a slightly different gain structure).

As a point of interest, I think the V6 version of the Trinity 18w amps running in 6v6 mode is more JTM45-ish. None of the inherent EL84 edginess when pushed hard. YMMV.

If you're looking for hair metal you aren't going to get there with that type of amp without some modifications or a boost. There's a reason most those dudes ran boost or ODs of some sort. 

BTW, the Marshall 18w design is a pretty loud amp. The 35-40w of a JTM45 isn't much louder in real terms. Remember that doubling the volume requires roughly 10x the power (all things being equal...which they're not). You're only looking at twice the power with a JTM45 over an 18w, so that's what...10 or 11% louder? I can't do math anymore...darn computers.


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## hollowbody (Jan 15, 2008)

Emohawk said:


> You can do the cascade mod on the Trinity 18, or the "Rhoades mod" (similar concept) on a JTM45/Plexi to get more gain. If you built a Trinity 18w TMB (the highest gain version) with that mod it should be pretty close to early 80's heavy metal territory, possibly even in Tiny Terror territory (but a slightly different gain structure).
> 
> As a point of interest, I think the V6 version of the Trinity 18w amps running in 6v6 mode is more JTM45-ish. None of the inherent EL84 edginess when pushed hard. YMMV.
> 
> ...


doubling the power will get you about +3db, so yeah, the JTM really isn't much louder than the 18w.


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## bcmatt (Aug 25, 2007)

I actually just rewired a homebuilt 18 Watt that I built for my Brother-In-Law. It was a different sort of 18 Watt but I converted it to a TMB. I'd say it is pretty handy because having an MV on the TMB channel and using the other one for clean, you can use an A/B pedal to flip between channels at the same volume. I also did a global Variable Voltage Regulator, which makes this amp very versatile for volume all around. So, you can get a sort of MV type distortion or just crank the normal channel and get more classic style distortion.
Here's a quick example of it that I recorded today flipping back and forth. It's probably set at about 60% plate voltage here:
[video=youtube_share;WqSyf9pZjcM]http://youtu.be/WqSyf9pZjcM[/video]

So, remember that VVR is a pretty handy thing to add to either amp as well.
I have the TMB channel almost cranked but its MV is at less than 1 out of ten. The normal channel without an MV is at 2 out of 10.


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## copperhead (May 24, 2006)

Thanks guys


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