NAD: Modded Marshall

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Bought this one off my tech. Started life as a 1987x, which he modded to a stock 2204. Years later, he did the JEL mods with each tweak on a seperately switch.

When I planned on buying it, I decided that I don’t need the stock 2204 sound as I have that pretty well covered, so I decided to hard wire the JEL mods in place and use the switches for additional mods.

The underlying circuit is the JEL, and then the switches:

- coupling cap ( 0.02uF vs 0.0022uF) to filter more or less bass early in the preamp. Can go for a more fat sound, or more tight and modern
- gain boost (JEL circuit attenuates after a gain stage, this has it unattenuated - sounds like more gain and bass)
- 3-way bright cap switch (middle position is no bright cap). Super handy with varying levels of gain, as well as the different coupling cap values.
- 3-way diode clipping (symmetrical and asymmetrical).
- tone switch, revoiced the tone stack. Goes from Marshall to something pretty unique
- NFB switch, can have standard marshall negative feedback or have it wide open like a dual rectifier
- depth pot

The stock sound is like a perfectly tuned JCM800 with a bit more gain (stock they’re a bit lighter on gain than people usually think - this sounds more like a boosted 800).

LOVING the bright cap switch more than I thought - with the diode clipping things can get a bit to spanky and removing it can balance things out nicely. Conversely, on other settings having a strong bright cap really gives the Marshall kerrang.

No NFB seemed like a bit of a gamble as it means the presence and depth do nothing. The amp sounds really open and dynamic and the chugs just bloom out like this. It’s loose and wild in a good way.
 
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Bought this one off my tech. Started life as a 1987x, which he modded to a stock 2204. Years later, he did the JEL mods with each tweak on a seperately switch.

When I planned on buying it, I decided that I don’t need the stock 2204 sound as I have that pretty well covered, so I decided to hard wire the JEL mods in place and use the switches for additional mods.

The underlying circuit is the JEL, and then the switches:

- coupling cap ( 0.02uF vs 0.0022uF) to filter more or less bass early in the preamp. Can go for a more fat sound, or more tight and modern
- gain boost (JEL circuit attenuates after a gain stage, this has it unattenuated - sounds like more gain and bass)
- 3-way bright cap switch (middle position is no bright cap). Super handy with varying levels of gain, as well as the different coupling cap values.
- 3-way diode clipping (symmetrical and asymmetrical).
- tone switch, revoiced the tone stack. Goes from Marshall to something pretty unique
- NFB switch, can have standard marshall negative feedback or have it wide open like a dual rectifier
- depth pot

The stock sound is like a perfectly tuned JCM800 with a bit more gain (stock they’re a bit lighter on gain than people usually think - this sounds more like a boosted 800).

LOVING the bright cap switch more than I thought - with the diode clipping things can get a bit to spanky and removing it can balance things out nicely. Conversely, on other settings having a strong bright cap really gives the Marshall kerrang.

No NFB seemed like a bit of a gamble as it means the presence and depth do nothing. The amp sounds really open and dynamic and the chugs just bloom out like this. It’s loose and wild in a good way.
That coupling cap switch is cool. IIRC those values are switching you between Superlead lead and something close to bass spec. Bet it sounds really cool.
 
Plenty of gain! Dig it!
Yeah, and just the standard 3x12ax7’s (which includes one as phase inverter and half of one as cathode follower for the EQ). The gain stages are all working pretty hard though and the diode clipping can take it into high gain territory.
+1000 for opening with the riff from Elite. :satan “When you’re ripe, you’ll bleed out of control”:headbang
Ha EVERYONE likes deftones
 
Dude, I figured it out.
This amp is the secret weapon blending it with another amp(s)
You can use all those killer options as a surgical EQ tools goin’ in or comin’ out.
Dude…….whoa.. FIRE IN THE HOLE!
Sure it would be a cool blending amp, I usually like to try and have the amp's full character on display rather than trying to hide behind other sounds. I used to blend way more before but I like going gung ho about it now
 
What a great sounding amp! For some weird mental block that I have I couldn’t drill on a old amp but I would not mind if someone else did and I bought it already like that, it would be so cool to experiment with different values for all those switches!
 
What a great sounding amp! For some weird mental block that I have I couldn’t drill on a old amp but I would not mind if someone else did and I bought it already like that, it would be so cool to experiment with different values for all those switches!
same here.

This is a reissue 1987x from about 10 years or so ago. Chris wanted a 2204 (50W) which Marshall still don't offer, so he decided to mod a 1987 into one as its not a ton of work. All the reissue's are pretty solid donor amps. Vintage ones should be left alone besides anything non-invasive/destructive. Same goes for Recto's too as far as I'm concerned. Pains me a bit to see Rev F and older get carved up. There's a lot more Rev G's out there, and even still I think there's no reason not to use one of the current production ones.
 
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