God’s Gift to Rock: A Late ’70s Marshall JMP 100 Watt

30 Sep God’s Gift to Rock: A Late ’70s Marshall JMP 100 Watt

(please note: this post is a follow up from a previous research: Angus Young’s Marshall Amplifier(s) & the “Back in Black Tone Project” )

EDITED: Members ROCKER and Sgace have helped me determine that this amp was NOT a super lead (NON master volume) but it was born as a Master Volume since its beginning. It was later modified as stated below. Have no idea of the differences yet 😛

So, it has arrived (for the record, this is a 1979 Marshall JMP 100w Lead).

The “Destiny” wanted that the first of the two JMPs I bought the other day to arrive was the the 100 watts.

So it was.

I quickly and swiftly hooked it to one of the two cabs I have now, the reissue non slanted cabinet with vintage 30s inside.

I blew a fuse the moment I turned it on, because the voltage (mains) selector was probably disabled when the amp was modded. No problem, I constructed a quick fuse and stuck it in.

Then it turned on.

Why have I waited so long? I don’t know. I thought Marshalls were Marshalls. Not true. They’re all different. So please be patient – you that have followed me so far: THIS is THE Marshall for me. A voice inside of me, after playing it, said “Thou shall not know any other after this”

Well folks, my quest for AC/DC tone from the mid to late 70s to early ’80s might have ended today: this amplifier is the best thing I ever connected into.

Do I sound exaggerated? I apologize. I am extremely, extremely excited and I am having a hard time to stay calm. My wife saw me and she understood right away something different was in the air.

I played it for circa thirty minutes. Now keep in mind this amplifier has been modified: let me give you – directly from the eBay auction I got it off – what the seller stated:

Genuine Lee Jackson Metaltronix Mod

This Marshall is in exceptional condition for its age and features all original Drake Transformers, and the complete Metaltronix Mod with Master Volumes 1 (front) and 2 (backside, also has a push-pull switch which allows it to serves as a power attenuator), 6-position Mid Frequency selector to morph the tonal characteristic from beefy blues to metal, and tube-buffered effects loop with Send and Return levels (the Return control is a push-pull switch, allowing you to engage the effects loop or bypass it to go straight onto Master (1) on the front). Lee’s signature and work completion date (smeared by control cleaners) are on the inside corner of the chassis, near the effects loop circuit (see third photo). Recently retubed with a matched quad of JJ E34L and five NOS Sovtek 12AX7WA preamp tubes. New three-prong power cable is included. Enjoy!

Back:

Now see the settings here:

And these are “guts” of it:

This was instant Back in Black (the album). I say, I mean, instant. Right away. I was blown away. Naturally, since i played it in my “laboratory”, I set the volume (the attenuator) at an extremely reasonable level. I could almost talk over it. Softer than I used to keep my 1987XL when was doing the tutorials thing back then (do you remember?).

This amplifier brought me back – partly – to when I was playing my 100 watts 1969 Super Lead (i.e., a 1959 model from 1969 I used to own).

There is a super attack that will support you/help you. The three or four SGs I tried into it were almost playing by themselves. A feeling of ease I had long forgotten.

If you followed me reading so far: I am in heaven. Do you remember when I was saying that gear has to sound good and make your life as a guitar player easier?

This one does. Whatever you do, whatever note you play, however you play it (soft, hard, biting, … ) sounds godly.

It’s hard to describe and no, I don’t have a video/audio for you yet.

As a completion to this project – you know how serious I am about this – I have investigated a bit on a good guitar microphone recently. I don’t have my Neumann U67 anymore.

I have a Neumann U47, but it needs repair, as it’s not working (and I’m bringing it to the shop on Monday).

So, what did I do?

I started a month ago studying some AC/DC images – recent ones – from a live show. I had seen this microphone on Angus’ and Malcolm’s cabinets:

Turns out this is an Audio-Technica AT4047 Condenser Microphone, with following features:

The Audio-Technics AT4047 Condenser Microphone is designed for professional recording and critical applications in broadcast and live sound. Transformer-coupled output and a specially tuned element provide sonic characteristics reminiscent of early FET studio mic designs. The AT4047 mic has exceptionally low self-noise, wide dynamic range and high SPL capability. It sports a vintage silver-matte finish on the microphone and shock mount. Audio-Technica includes a protective case and AT8449/SV shock mount with the AT4047 microphone. Requires phantom power.

Audio-Technica AT4047 Condenser Microphone Features:

• Gold-plated, specially contoured and aged, dual-diaphragms
• Switchable 80 Hz hi-pass filter and 10 dB pad

Muisican’s Friend link

Update: it is confirmed that AC/DC did use this microphone during this tour. From sound engineer that ran AC/DC live:

AC/DC is the best rock band there is,” enthuses front-of-house engineer Paul “Pab” Boothroyd. That means a lot coming from a man who’s been Paul McCartney’s live engineer for the past two decades, and whose list of clients includes Faith Hill and Paul Simon. Boothroyd has handled FOH duties for AC/DC since the band’s 1996 Ballbreaker Tour, and he’s back at the helm for their latest, the Black Ice World Tour, which promotes Black Ice, the group’s first album in eight years.[…]

As for guitar amps, it’s “Marshall, Marshall, Marshall, Marshall, 11, 11, 11, 11, loud, loud, lots of them,” Boothroyd says with a laugh. “There are about 20 [amp] cabinets up there. They are all flat-out — there’s no gimmick here, They’re there to spread guitar across the stage.” The cabinets have 100-watt Marshall heads, which have been tweaked by the tour’s amp technician to run hotter than a standard amp. “This is okay — it just means you go through a lot of tubes, but it gives it that sound,” Boothroyd says. “I put one mic on one cabinet, an Audio-Technica 4047. I’ve tried various microphones, much to Malcolm [Young, rhythm guitarist] and Angus’ [Young, lead guitarist] disgust because they’d be quite happy with just an SM57 on there. But I wanted to capture some other qualities, so I went for a slightly larger-diaphragm mic, and I found that the only one I really liked was the A-T 4047.”

(from Mixonline)

I thought that if it sounded good for them, it will sound good for me, too.

So I got one. You will have to wait until I have it – a bunch of useless days – and then, I will overload you with experiments.

I just couldn’t walk away from this little room today. I couldn’t… but I had to. Family needs me.

I am leaving you with a couple of foolish pictures of SoloDallas’ “laboratory”.

Love, Fil